THE SHOCK AMD VIBRATION DIGEST

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SVIC NOTESThe 54th Shock and Vibration Symposium was held in Pasadena, California, on October 18-20, 1983.

It was a well-ettended and highly succsful meeting. I would like to thank all of the invited speakers,

chairmen, co-chairmen, panelists, presenters and attendees of this symposium. Without your excellent

technical support and participation, the symposium would not be possible.

Many participants commented to me on how smoothly the meeting went. The credit for this must

go to the staff of SVIC, Rudy Volin, Jessica Hileman, Betty McLaughlin and Mary Gobbett. The

credit for the successful administration of the meeting must go to Mrs. Hilemen since she was respon-

sible for all of the final arrangements and took care of the dozens of small details necessary to run a

successful meeting. I would also like to thank Dr. Ben Wade and all the members of the Jet Propul-son Laboratory who provided such excellent support. The Von Karmen Auditorium at JPL was a

superb meeting site. JPL also arranged a tour of some of their more important activities, including

their spec flight control center and environmental testing facilities. A few short technical presents-

tions on new JPL programs and a short review of JPL's past accomplishments were given and wallreceived. The people who want on the tour were very impressed with the quality of the material

presented.

The 54th Shock and Vibration Symposium had several notable features. In the Opening Session,

Bob Ryan, of NASA Marshall, did a good job of explaining how the job of the shock and vibrationengineer is becoming more and more difficult due to the increasing complexity and nonlinearity of

today's spacecraft. In fact, the Opening Session emphasized the increasing usage of space in thefuture. Three excellent and thought-provoking Plenary talks ware given by Strether Smith, George

Morosow and Bill Baker. Rudy Volin organized an interesting day-long session on the new MIL-STD-

81OD and we managed to give away over 300 copies of the new standard at the meeting.

Other sessions at the meeting covered Structural Dynamics, Machinery Dynamics and a collection of; "Vibration problem. I received many favorable comwriets about Session I1B on Spe Vibration.

. ICredit should go to Jerome Pearson of AFWAL who organized the session and Invited several of the

speakers.

Other noteworthy features of the meeting were the large number of seions related to blast and

shock including the two full days at JPL which were devoted to Navy problems. Don Lund, Stan

Herman and Dew Hurt of Navel Sea Systems Commend were mostly responsible for organizing the

PL sessions which included inviting many of the speakers.

A big "ell Done" to all. Thanks for helping us make the 54th Shock and Vibration Symposium a

successful one.

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EDITORS RATTLE SPACE

TECHNICAL MEETING ATTENDANCE

It appears that attendance at technical sessions held at meetings continue to de-cline. In fact, it is not uncommon for authors to talk to each other at many ses-sions. This does not necessarily imply that engineers are not attending meetings,conferences, and symposia. It means that in many conferences the technical ses-sions are not the focal point.

I believe there are a number of reasons for this trend. Continued republication ofthe same material in slightly altered form does not motivate people to attend ses-sions. Publication of irrelevant material - whether it is a super-technical treatise,technology with no practical application, or solutions to trivial problems -- is nextto worthless. Exhibits and social events often become the focal point of a meeting.While these functions are essential and contribute to the effectiveness of a meeting,their importance must remain in prospective. After all, the technical sessions arethe stated principal function of the meeting.

Economics plays a big role in attendance at meetings. Often employers are notwilling to spend money on "frills" such as technical meetings. In the absence ofnew development or crisis, management is reluctant to support long term educationof an employee. It is unfortunate when an engineer is requested to perform atoptimum level on short notice -- the costs involved for mediocre performance mayexceed those expended in a long-term educational program.

In order to stop this declining attendance, I believe we are going to have to selectmore carefully the material that is presented -- even if it is less of it. More is notalways better. The technical sessions need to be brought back as the focal point !of the meeting. This can be done in part by establishing guidelines for the materialto be presented at meetings. Input on the interests of technical people would behelpful to meeting organizers and planners. This can be accomplished by morequestionnaires. In addition, the effort to educate employers and employees (engi-neers) about the value of long-term learning should be intensified.

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A TECHNICAL NOTE ON EVALUATION OF DAMPERS

T.V. Gopalad*

Abstract. The significance of the inverse standing 0 comparatively large mass of the damperwave ratio (ISWR) test and its role in assessing 0 cable bending at the location of the dampersdampers and in obtaining other information needed due to asymmetric action of the damperfor their evaluation are discussed in this technical weights or cablesnote. 0 an unbalanced torsion on the cable at the

point of attachment of the damper

The inverse standing wave ratio (ISWR) test has been A simple mass suspended on a cable can protect theused to assess the effectiveness of overhead line suspension point by damping the portion of thevibration dampers over the expected range of fre- cable between the suspension point and the mass.quency of aeolian vibration of cables. The ISWR However, the mass imposes dynamic stresses on thetest is recommended as a supplement to dynamic cable. The attachment of a heavy mass increases thecharacteristics tests on stockbridge dampers in stiffness of the point of attachment and results inIS:9708. Based on the results of the two tests the dynamic stresses there as well as at the suspensionadequacy of the damper regarding both dynamic point. The inherent asymmetry of multi-resonanceperformance and efficiency can be assessed. The dampers can also cause dynamic stresses at the loca-dynamic characteristic tests provide quantitative tion of the damper even if the mass of the damperinformation regarding damping capacity for a given is not great; e.g., cable bending is possible whenvertical movement of the damper under kinematic one of the two masses of a stockbridge damper is inexcitation; information is obtained concerning the resonance, either in the cantilever mode or theextent of such movements possible in the field. But bending mode. Torsion of the cable is possible ifthe ISWR test indirectly provides both the mobility significant imbalance exists in the masses of a dog-of the point of attachment of the damper when bone damper.placed on the conductor and the damping capacity.

: The mass-like behavior of the stockbridge damper

Need for an Appropriate Method for Evaluation of and its variations cannot be assessed by dynamicDampers characteristic tests. The ISWR test is useful in assess-External dampers have been used in transmission lines ments but does not seem to be helpful in assessingto protect cables at suspension points at which the bending and twisting action of the cable. Therefatigue failures have been known to occur. But some is thus a need to develop a better system of damperdampers cause cable failure at their points of attach- evaluation.ment, and the section of cable at the suspensionpoint is not damaged. The damper therefore has Recommended Method for Evaluationshifted the failure from the suspension point to the Dynamic characteristic tests on a damper providepoint at which the protective device is located. The quantitative information regarding damping capacitydamper thus transfers all or most of the dynamic in terms of damping power per unit displacement ofstresses to a point at which static stresses are less damper clamp. No information regarding possiblesevere than those at the suspension point. This damper displacement in the field is obtained; i.e.,transfer of stresses can be attributed to any of various the mobility of the point of attachment of dampercauses: on the cable while in the field is not obtained. No

bnlor Deputy Director, Ceftral Power Rewch Institute, P.O. Box 1242, Anplore W 012, Indb

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information about added damping and hazard pos- Summary of Recommendations for Evaluation ofsible at this location can be obtained from these tests. DampersIf it is assumed that a damper is immobile due to itsmass, it will not contribute any damping even if it 1. If any one test is to be depended on for evalu-possesses good dynamic characteristics. Such a ation of dampers, it is the ISWR test. Thedamper will show an ISWR of 0.0. Conversely, an damper that is efficient over the desired fre-ISWR test that shows the desired level of damping quency range is recommended.indicates that the damper does not cause considerable 2. Dynamic characteristics tests should be comple-stiffening of its point of attachment on the cable; mented by ISWR tests for evaluating dampers.hence the damper is performing well. An ISWR test Primary consideration should be given to ISWRof dampers also serves as an independent means of test results.evaluation. 3. Among dampers that are adequate based on

ISWR and dynamic characteristics tests, the oneHowever, the mass of the damper is a good index that weights least is best.when one damper must be chosen from a number of 4. The choice among symmetric dampers shoulddampers having satisfactory dynamic characteristics be based on measurements of the assembledand ISWR results. For identical dynamic character- damper and of the damper stripped into itsistics and acceptance curves obtained by ISWR tests components.-- not realized in practice -- the damper weighing the 5. If an asymmetric and symmetric damper meetleast is the best choice. Unintentional asymmetry in the requirements equally, the choice can bedampers can be assessed by taking physical measure- the symmetric damper.ments on the assembled damper and stripping a ran- 6. Conclusions at 4. and 5. above are of minordomly selected sample; e.g., stripping a stockbridge consideration, however.damper into messenger cable, masses, and clamp.

Evaluation of stockbridge dampers designed with Thanks are due to the Director of CPRI for grantingasymmetry with respect to the damper clamp - in permission to publish this note. Thanks are also dueother words damper performance is dependent on to Prof. S. Durvasula, Aeronautical Engineeringintentional asymmetry, as in a four-R damper - de- Department, and Prof. G.R. Nagabhushan of Highpends on tolerance levels of results of asymmetry. Voltage Engineering, Department of Indian InstituteHowever, a symmetric stockbridge damper that of Science, Bangalore, India, for their guidance in thismeets the requirements imposed by an overhead line work. The author also wishes to thank Mr. M. Swam-might be preferable to an asymmetrically designed inathan for assistance in preparation of the manu-damper of the same type. script.

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ofuthey Shoc andlsiLITERATURE REVIEW: oftlw'hocs

Vibration literature

The monthly Literature Review, a subjective critique and summary of the litera-ture, consists of two to four review articles each month, 3,000 to 4,000 words inlength. The purpose of this section is to present a "digest" of literature over aperiod of three years. Planned by the Technical Editor, this section provides theDIGEST reader with up-to-date insights into current technology in more than150 topic areas. Review articles include technical information from articles, reports,and unpublished proceedings. Each article also contains a minor tutorial of thetechnical area under discussion, a survey and evaluation of the new literature, andrecommendations. Review articles are written by experts in the shock and vibrationfield.

This issue of the DIGEST contains articles about dynamic behavior of underground

structures and stable response of damped linear systems.

Dr. G.D. Manolis of State University of New York, Buffalo, New York has writtena review article that provides a brief historical perspective to the general subject ofdynamic behavior of underground structures and summarizes the work done in thisarea during the last few years.

Dr. D.W. Nicholson of Naval Surface Weapons Center, White Oak, Maryland andDr. D.J. Inman of State University of New York, Buffalo, New York have writtena paper that updates and expands a previous review concerned with several aspectsof the response of damped mechanical systems. Topics include asymptotic stability,oscillation conditions, forced response bounds, and eigenvalue localization.

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DYNAMIC BEHAVIOR OF UNDERGROUND STRUCTURES

G.D. Manolie

Abstract. This article has two purposes: a) to provide This type of behavior lends credence to static (6]a brief historical perspective to the general subject and quasi-static methods of design 17-91. Theseof dynamic bwavior of underground structures and methods assume that the seismic forces a structureb) to summarize the work done in this area during experiences can be computed by multiplying the massthe last few years Underground structures can be of overburden soil by the maximum acceleration thatclose to the surface or deeply buried and can be does not cause soil failure. Monitoring of accelera-subjected to harmonic, shock, or seisnic excitation& tions developed in basements and other embeddedExperimental, analytical, and numerical methods structures during small to medium earthquakes (10]of approach are discussed. confirms this type of behavior. Only if significant

inertial and/or stiffness mismatch exists between thestructure and the surrounding medium does the

There is a great range of use of underground struc- possibility of failure due to progressive distortiontures. Examples include buried pipelines used to of the buried structure exist. At present, little infor-transport liquids and gases; traffic movement through mation on this case is available.buried tunnels; culverts used for drainage and as un-derpasses; tunnels cut through mountains; buildingsbuilt beneath the surface of the earth to provide EXPERIMENTAL WORKstorage and to serve as shelters; and vertically buried The literature is rich in experimental investigationssilos used for placement of delicate machinery and on the dynamic behavior of underbround structuresinstruments. Reasons for the widespread use of under suddenly applied (shock) loads. Most of thisunderground structures include conservation of work was done in the 1960s and early 1970s.space in crowded urban areas, protection againstclimatic extremes, and amelioration of some of the Bulson [11] examined the influence of cover depth Ieffects of dynamic loads imposed by such surface on the collapse load of horizontally placed thin-disturbances as earthquakes and air blasts [1-31. walled cylindrical metallic tubes in soil under a

surface pressure applied both quasi-statically andThe static behavior of buried structures involves soil dynamically. Failures included local snap buckling ofarching. Under normal circumstances soil arching the rim and/or caving of the roof. The collapse pres-develops [41 and transmits to the surrounding soil sure in the static case rose rapidly with increasinga large part of the overburden pressure created by the cover depth until the cover was equal to the diameterweight of the cover soil. Arching action is substantial of the tube. Thereafter, no significant increase in theeven for shallow burial; Krauthammer's [5] recent collapse pressure occurred with increasing cover. Inre-evaluation of experimental data on reinforced the dynamic case, complete tube collapse occurredconcrete box-type structures indicates that soil when the peak blast overpressure was in a zone veryarching can account for up to 70% of the measured close to the static pressure that would cause collapse.resistance to the static overburden load. Results from similar tests (12-15] essentially agree

with Bulson's conclusions. Previous investigatorsFor the majority of underground structures under [16, 171 had examined the validity of the similitudedynamic loads, soil-structure interaction is negligible, relations used to extrapolate the dynamic responseConsequently, the structure conforms to free field of real underground structures from experiments onsoil deformations and small dynamic stresses develop, scaled models."Ahbmat freAwr. Dwrtmmt of CWi E ngdnwh .SteOn Unlvorsit of New York, Ruftfl. NY 142W

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During the last few years, emphasis in experimental have almost the same inertia to stiffness ratio as thework has shifted from small-scale flexible models, material removed, they essentially conform to soilwhich essentially conform to the free field motions motions; the stresses induced are small comparedof the soil, to larger scale stiff models [18-22]. The to the design stresses resulting from the weight ofresponse of 1:30 scaled models of stiff reinforced the overburden. The tests also indicated that theconcrete cylindrical missile shelters subjected to dynamic response is more pronounced the closersevere dynamic shock ioads was examined [19] and the structure is to the surface and that the naturalcompared with the response of similar 1:6 scaled frequencies and damping ratios of the soil are virtu-mLdels from a parallel program [18] . In the tests ally unaffected by the presence of the buried modelsand was rained over a vertically placed cylinder 4.2 structure. The same behavior patterns were observedft in height with a base and a cap. The model was in similar experiments [29, 301. In one case [29]contained in a large rigid facility; explosives produced a pile foundation was examined; the deformations ofan air blast that impinged on the soil surface. The a prefabricated highway tunnel model were measuredstronger of the two models tested exhibited linear in the other [301. Earthquake simulators are usefulelastic response. The other failed because excessive in that they can accurately reproduce virtually anybase flexure cracked the base connection of the type of dynamic record.cylinder. The cylinder itself survived the blast. Goodcorrelation of results between the two programs was The behavior of subaqueous buried tunnels duringobtained. It can therefore be concluded that suddenly earthquakes was first investigated by Okamoto andapplied excitations, generated either by dropping Tamura [31], who vibrated three-dimensional modelsweights or by firing explosive charges, create an on a shaking table. The test results were necessarilyextremely fast response. As a result inertial effects linear elastic because gelatin was used for the soildo not develop; the buried structure simply experi- layers and the tunnel was made of silicon rubber.encesa uniform acceleration field. In addition, earthquake observations were made

at the site of the real tunnel, and a mathematicalIn sharp contrast to blast loads, oscillators transmit model was formulated for seismic design studies.both forces and motions to the buried structure. The results obtained from the experiments, theobser-Various investigators [23-27] have performed forced vations, and the mathematical analyses were con-vibration tests using oscillators or vibration genera- sistent and indicated that elastic subaqueous tunnelstors. Some results [25] indicate that the exciting with no mismatches of inertia and flexibility moveforce developed in a full scale nuclear reactor building in phase with the ground during an earthquake.is directly proportional to the frequency of oscilla- Furthermore, the strains developed in the tunneltion. In general, oscillators can produce a variable are due to nonuniform displacements of the ground.loading force at constant frequency or a force of con-

stant magnitude with varying frequency [26]. Oscilla- Although large earthquakes are infrequent, micro-tors are used to study the natural frequencies of soil seismic activity in such countries as Japan is continu-and embedded structure(s). ous. It not surprising that full-scale structures such

as underground tanks [32], underground structuresLittle work has been done on buried structures using [33] , submerged tunnels [31, 34-36], pile founda-earthquake simulators. Perhaps the most involved tions [37], and highway bridges [381 have beentesting to date is a large number of experiments on instrumented and their dynamic responses recordedscaled models of underground stations and tunnels during small earthquakes. In most of this work suchfor a subway transport network [281. A total of methods as finite elements or lumped parameter214 tests were completed on two shaking tables. formulations were subsequently used in attempts toSeventy different s-ijuctural models were subjected correlate actual observations with numerically ob-to harmonic, shock, and seismic excitations under tained results. The conclusions reached by the variousconditions of plane strain. The information generated researchers are that a) dynamic strains and stressesfrom these tests confirmed qualitative information developed in structures are proportional to soilgained from earthquake observations [10] about the accelerations (although at high frequencies thisdynamic bendvior of horizontally buried structures. proportionality is disturbed), b) axial strains in theIn particular, because the majority of these structures buried structures are amplified at low frequencies,

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c) bending strains increase at high frequencies, and proaches the natural frequencies of the system is notd) natural frequencies of the soil layers are only present here [49, 50].slightly influenced by the presence of the structure.

NUMERICAL METHODSANALYTICAL METHODS

Two major categories of numerical techniques areAnalytic work on highly idealized representations of currently being used for both linear and nonlinearunderground structures began in 1898 when Kirsch dynamic structure-medium interaction analyses:[39] investigated the stress concentration around a approximate continuum and discrete (lumped param-circular hole in an infinite elastic plaste under a uni- eter) models. The most widely used approximateaxial static stress. Dynamic stress concentration continuum method at present is the finite elementstudies for two-dimensional structures by analytical method (FEM). Its accuracy depends, in general,methods were done in the early 1960s by Baron and on element size, mesh dimensions, and assumed dis-his co-workers 1401 and by others [41]. These placement functions [51, 52]. In principle, the FEMinvestigators determined the dynamic stress and is a versatile technique when applied to structure-displacement fields produced around a circular medium interaction problems because it can handlecylindrical cavity in an infinitely extending elastic complex structural geometry, medium nonhomo-medium due to the passage of harmonic or transient geneities, large deformations, and complicatedwaves. The case of a lined circular cylindrical cavity material behavior in both two and three dimensions.in an infinite medium was also considered [42, 43]. The finite element formulation of a problem resultsThe diffraction of horizontally polarized shear waves in a system of equations that can be solved by modal(an anti-plane strain problem) by cyiindrical and analysis, Fourier transform techniques, or step-by-elliptical canyons on the surface of the half plane step integration schemes.[44] and by a lined circular cylindrical tunnel buriedin the halt plane [451 has also been studied. Such The major deficiency of the FEM is that an infinitetechniques as the wave function expansion method or semi-infinite medium is represented by a finiteor integral transforms along with the concept of size model. The obvious remedy of using a very largeseparation of variables were employed. In a detailed mesh, as compared to structure, is uneconomical.review of the work done on dynamic stress concen- Therefore, considerable effort has been directedtration up until the year 1972, Pao and Mow [46] toward obtaining non-reflecting or transmittingconcluded that analytical methods of solution are boundaries that are placed at the ends of the meshpossible only for problems with cylindrical, elliptical, to allow for energy radiation [53-55]. Transmittingspherical, or parabolic geometries and exhibiting boundaries can be either frequency dependent orelastic material behavior. Even very recent solutions independent and can absorb body waves, surfaceto problems involving two-dimensional diffraction of waves, or both. *The best transmitting boundaryelastic waves by inclusions, cavities, or shells in a model at present is valid for axisymmetric problemshalf space [47, 48] are restricted to circular cylindri- and reproduces the far field in a manner consistentcal geometries of the discontinuities. Therefore, for with the FEM discretization of the core region [55].embedded structures of arbitrary shape under general A comparison of transmitting boundaries is availabledynamic disturbances, numerical methods of solution [56]. In the case of a wave propagation problem, anmust be used. additional difficulty is that the motion at the bound-

aries of the mesh must be prescribed without inter-It is of interest to note that in such linear solutions, fering with the already placed transmitting bound-dynamic stress concentration factors do not exceed aries.the static counterpart by more than 15%. This is truefor transient as well as harmonic excitations, the lat- The FEM can employ three-dimensional, axisym-ter resulting in an upper bound solution for wave metric, and two-dimensional solid elements. The firstscattering problems. It can therefore be concluded type results in enormous computation requirementsthat the resonance phenomenon observed in most dy- that only a few researchers can afford. Therefore.namic systems when the frequency of excitation ap- at present the other two types of elements are often

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used. Luco and Hadjian [57] found that, for nuclear the medium -- with due consideration to the inter-power plants, a two-dimensional approximation of action phenomenon - and allows for an efficientthe three-dimensional problem results in considerable dynamic analysis of the structure alone. An imped-underestimation of the response. ance function lij is generally a particular reaction

of the medium at boundary point i due to a pre-The finite difference method (FDM) has also been scribed type of displacement at boundary point j,employed for the solution of dynamic structure- with all other possible displacements of the mediummedium interaction problems. For example, Ang and boundary prescribed as zero. For a three-dimen-Newmark [58] determined the response of under- sional continuum there are, in general, three possibleground structures to surface blasts assuming elastic components of translational motion at a particularsoil behavior. Ang and Chang [59] introduced point and three analogous reactions. Exact expres-elastic-perfectly plastic soil behavior using the Von sions for impedance functions can be obtaine -rMises yield criterion in the same problem. Trans- very few cases. In most instances, analytic F. ,bmitting boundaries for finite difference or finite sions for these functions are obtained under r 3delement meshes and time domain formulations have boundary conditions, mostly by assuming calso been developed [60, 61]. Numerous commercial reactions under a given type of displacement Bprograms for separate or combined FEM and FDM zero (uncoupling). Finally, successful attemptanalyses are currently available, been made at obtaining impedance functions 1:

numerical methods as the FEM [55].Nelson and Isenberg [62] and Nelson [63] used the

FDM to model a large soil area surrounding a soil These ideas have found extensive use in foundationisland that includes the embedded structure. The problems. For instance, dynamic stiffness and damp-soil island is modeled by the FEM. The purpose of ing coefficients in complex form and as functions oftheir three-dimensional and two-dimensional studies frequency have been determined for the case of awas to determine the effects of a powerful air blast rigid disc on an elastic half space [70, 71] , the caseon the embedded structure, of a rigid strip on an elastic half plane [72] , the case

The interaction effects between parallel tunnels due of a partially embedded rigid hemispherical footing

to moving railway trains has been studied by a dy- [73], and the case of a flat circular foundation

namic plane strain FEM [64]. Haupt [65] used a supported on a layered medium [74].FEM in conjunction with what he terms an influencematrix to determine the effect of a protective ob- Relative little work has been done for the case of stacle in the propagation of surface waves. The near flexible foundations. Some information is available.

field ground motions from the San Fernando 1971 Lin [75] treated analytically the case of vertical andearthquake were modeled by dynamic plane strain rocking harmonic motions of a flexible circular disc

finite elements in the frequency domain [66]. The resting on a viscoelastic half space. Iguchi [76] used

seismic behavior of an underground reactor building analytical means to approximately solve the problem

using two-dimensional finite elements was reported of vertical motions of a long flexible rectangular mat

in f67], A general-purpose FEM program has been under oblique seismic motions. Dasgupta [77] intro-produced for structures embedded in multilayered duced a substructure deletion method for two-dimen-

linear viscoelastic soil systems under any combination sional embedded structures in which both FEM and

of surface and inclined body waves by Lysmer and analytically obtained soil impedances are used. Thehis co-workers [68]. subject of the dynamic analysis of surface and em-bedded foundations is extensive; a complete list ofDiscrete or lumped models have competed success- references to 1981 is available [78]. Impedance func-fully with approximate continuum methods in tions for a vertical pile embedded in a linearly elasticstructure-medium interaction problems [69]. The or viscoelastic layered medium and subjected tokey idea behind a lumped parameter approach is to harmonic motions at its top have also been founddetermine value for the mass, stiffness, and damping [79].coefficients that essentially represent the medium.Use of these coefficients, also known as impedance Extension of these concepts to underground struc-functions, effectively uncouples the structure from tures is hampered by the fact that the boundary value

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problem for the analytic determination of the appro- can be established. This is indeed the case if thepriate impedance functions is very difficult, even FEM is coupled with the boundary element methodafter some boundarV conditions are relaxed. For (BEM), or if only the BEM is used [86, 87]instance, the low frequency oscillations of a rigidcircular disc buried in and in bonded contact with a The basis of the BEM is the application of Green'slinear elastic medium was developed in the context Theorem to the governing quasi-linear partial differ-of a mixed boundary-value problem associated with ential equations of the problem on the unknown vari-two equivalent half spaces [801. able. In addition, a fundamental or particular solu-

tion representing a point source field; i.e., a Green'sThe dynamic response of a tunnel has been investi- function, is needed. This procedure results in a sur-gated 131, 81, 821 under the strong simplifying as- face integral that appli, s only to the boundary of thesumption of modeling the tunnel as a beam on an problem's domain (for linear problems) and incorpo-elastic foundation, and by Hindy and Novak [83] rates the boundary conditions directly. In contrast,who derived soil reactions from approximate consid- both the FEM and the FDM require full domain dis-erations of static and dynamic continuum theories. In cretization. Development of this methodology toolder work 113, 84], the response of foam-isolated engineering problems has resulted in excellent solu-buried tunnels to the passage of a plane compression tion accuracy and numerical efficiency [87].wave was investigated; the soil-structure interactionwas postulated a priori so as to uncouple the free Two basic approaches for the solution of transientfield motions from the structure motions. The steady problems involving underground structures exhibitingstate axial and lateral vibrations of a soil-pipe system linear elastic behavior by the BEM are a) solution ofexhibiting Coulomb friction at the interface were the problem in a Fourier transform [88-91] or arecently studied [851 by modeling the pipe asa long Laplace transform [92-951 domain by the BEMelastic rod with the frictional stresses uniformly approaches followed by a numerical inverse trans-distributed around the circumference, formation to obtain the response in the time domain;

and b) time domain formulation and solution of theIt should be emphasized that both categories of problem by BFM approaches in conjunction withnumerical methods will produce perfectly acceptable step-by-step time integration schemes. This has beenresults in the hands of a skilled analyst. However, the done for both antiplane strain [96] and plane strainmethods themselves suffer from certain shortcomings. [97, 98] cases. Relatively simp! !-two-dimensionalFirstly, the numerical integration formulas used with problems were solved using these methods: the casethe FEM introduce some artificial damping in the of buried unlined [89-91, 93, 97] or linad [91, 94]system. Next, the radiation condition necessitates circular cylindrical cavities under longitudinal orthe use of transmitting boundaries the physical transverse waves and the cases of buried square orcharacteristics of which are not completely under- horse-shoe shaped cylindrical cavities under longi-

stood at present. The FDM has the same problems tudinal waves [89, 90].

as the FEM; in addition, the incorporation of bound-ary conditions is a formidable task. Lumped param- The use of special restricted Green's functions de-eter models are perfectly acceptable for rigid surface fined for the half plane have enabled a number offoundation problems. Great difficulties arise, how- researchers (99-101] to consider in the frequencyever, in the analytic determination of appropriate doma , the diffraction of horizontally polarizedcompliances for problems involving embedded transverse (shear) waves by irregular surfaces (can-foundations or buried structures. yons), an anti-plane strain problem. Anti-plane

strain cases in elastodynamics are essentially one-A more fruitful approach to problems of this kind dimensional problems and are identical to the scalarappears to be one in which both the far (medium) wave propagation problem, which has been exten-and near (structure) fields are determined by suitable sively investigated by workers in the field of acous-numerical methods. In this approach the geometric tics and water waves. Dravinski (102] used a sourcedamping (infinite distance radiation condition) is method, which is similar to an indirect 8EM. inautomatically accounted for, and the coupling of conjunction with a Green's function to recover thethe two fields in the form of interface compatibility displacement field around an alluvial semi-elliptic

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valley under harmonic body and surface waves, pressure generation, and is easy to implement numeri-Manolis and Beskos [95] employed kernel functions cally. A formulation in terms of stress invariants isconstructed from full plane fundamental solutions to adopted; only one more experimental parameter ininvestigate the transient response of a cavity in the addition to those required for classical state modelshalf plane, is required for complete description of the model.

For foundation problems it is necessary to resort tointegral equation formulations in order to obtain CONCLUSIONsolutions to the mixed boundary-value problem;this problem is a result of the dynamic analysis of From observations, experimental work, and resultsrigid three-dimensional foundations of arbitrary of both analytical theories and numerical methodsshape embedded in layered media. For instance, reviewed herein, it is clear that no significant prob-the recent development of efficient methods to lems are experienced with underground structurescalculate Green's functions for layered viscoelastic during dynamic shaking if the materials behavemedia [103, 104] makes possible the use of integral elastically and if the relative deformations betweenequation methods for the evaluation of impedance soil and structure are small. Thus, from an engineer-functions for such cases. These methods are also ing point of view, placing structures below the surfaceapplicable to the computation of foundation input is safe.motion. The case of flexible foundations has beeninvestigated [105-108]. These researchers combinedthe FEM used for the foundation plate with the REFERENCEScontact soil stiffness obtained analytically via aGreen's function approach; they studied numerically 1. Baker, R.F., "The Use of Underground Spacethe dynamic response of foundations resting on an to Achieve National Goals," ASCE Under-elastic half space, ground Construction Research Council (19721.

The major shortcoming of the BEM is a lack of 2. Fairhurst, C., "Going under to Stay on Top,"suitable Green's functions. This makes difficult the Underground Space, 1(2), pp 71-86 (1976).extension of the method to problems involvingnonhomogeneous media. However, the dynamic 3. O'Sullivan, J.J., Editor, Protective Constructionversion of the BEM cannot yet be considered an in a Nuclear Age, Vol. I, McMillan (1961).established problem solving tool.

4. Abel, J.F., Mark, R., and Ricnards, R., "Stress-

The final item to be considered is selection of appro- es around Flexible Elliptic Pipes," Proc. ASCE,priate constitutive equations to model the geological 99 (SM7), pp 509-526 (1973).medium in which the structure is embedded. Inrecent years a number of models for describing the 5. Krauthammer, T., "Re-evaluation of Test Re-

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12

Struc. Mech. Reactor Tech., Berlin, W. Ger- crete Structures under Air-Blast Loading,"many (1971). H.G. Harris (Ed.), Dynamic Modeling of Con-

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STABLE RESPONSE OF DAMPED LINEAR SYSTEMS

D.W. Nitholsm" and DJ. lumm"

Abstract. This paper updates and expands a previous DAMPED LINEAR SYSTEMSreview concerned with several aspects of the responseof damped mechanical systems. Topics include For the most part attention is given to the systemasymptotic stability, oscillation conditions, forced described byresponse bounds, and eigenvalue localization. Con-sidereble progress has been made on the last three M + Di + Kx = f(t] (1)topics but little on the first. Several simple newresilts are stated. k(o) = x0 x(o) = x0

where x~t) is the n by 1 displacement vector; f(t)An earlier review [11 is updated and to some extent is the n by 1 force vector, considered known. Theexpanded in scope in this article. Four aspects of the symmetric matrices M, 0, and K represent mass,response of time-invariant damped linear mechanical damping, and stiffness, with M and K positive defi-systems are treated; in particular nite. Some comments are included on the case in

which D is not positive definite and in which the0 conditions for asymptotic.stability system matrices are not symmetric.

* conditions for oscillation To a lesser degree than for discrete systems work isreviewed on distributed parameter systems governed

0 bounds on forced response by

* locaiization of system cigenvalues 7+ L, [ix + L2 [x] = f on S1 (2)

Comprehensive reviews of the properties of damped B[x) = o on a 11systems are available [2-10]. The scope here is nar-row, but it is hoped that the discussion is thorough x(r, o) = x. ;(r, o) = o

i for the topics examined.The displacement vector x now depends on spatial

For the most part, the system under study for pur- coordinates represented by r; L1 , L2 , and B areposes of this review is discrete and symmetric and partial differential linear spatial operators. Thehas positive definite coefficient matrices. However, properties of Lt, L1, and B, as well as the definitionthere is some discussion of distributed parameter of the domain fl and the boundary a ,1 have been

systems, asymmetric systems, and systems with presented in detail (12].indefinite damping.

The contributions of the investigations cited here ASYMPTOTIC STABILITYfind applications in a wide variety of design andanalysis settings in which vibration control is central. The system represented by system equation (1) isFor example, simple techniques have been sought to called asymptotically stable ifobtain optimal damper distribution for a large flex-ible structure 11) . jxj -o as t -bo

*foh,6I~ 8ifapons Coew, fte OaMk, A#D 20910'Sam G*4wWv, of Now York at ouffb., Duffelo. NY 14210

I: 19

whenever f(t) = o for t > o. System equation (1) stability still holds if and only if the matrixcan without loss be reduced to the first order system[13A [D. DM- 1 K' D(MIK) 2 ' .... D(M-IK)n1 ]

dlz- + Az q(t) (3) has rank n [18].dt

where If D is asymmetric, asymptotic stability need notresult. In fact, if D is skew-symmetric and K is posi-

M-10 M'K 1 f tive definite, the system is stable but not asymptoti-

definite) and D is skew-symmetric, the system can

still be stable; i.e., gyroscopic forces can be used toFor asymptotic stability it is sufficient if stabilize an unstable 3ystem. However, if positive

definite damping is introduced, the system againRe(Xj(A)) > o (4) becomes unstable. This is known as the Kelvin-Tait-

Chetaev (KTC) theorem [17, 18]. If, in addition, thefor all 1 < i < 2n where X. is thejth eigenvalue of A. matrix K is asymmetric, a form of the KTC theoremIf (4) holds, A can be called a stable matrix, still holds [191. Namely, dissipation can cause

instability in systems that are stable due to theNecessary and sufficient conditions for A to be stable presence of gyroscopic forces alone if the matrix Kare classical results associated with Lyapunov; they is symmetrizable; i.e., similar to a symmetric matrixare briefly summarized here. Let C be any positive [20].definite symmetric matrix. Then A is stable [14] ifand only if there exists a positive definite Hermitian Bounds on the eigenvalues of the solution matrix Pmatrix P such that in equation (5) have been derived [21-23] using

matrix norm arguments; extremal properties of theAP + PAT = C (5) eigenvalues of symmetric matrices have also been

used [24, 25]. Unfortunately, no simple conditionsC can be chosen as the identity matrix I. have yet been derived on D less restrictive than

positive definiteness. A generalized Lyapunov theo-The most direct way to verify the stability of A is to rem has been introduced [14] that gives conditionsgenerate the numerical solution for equation (5) with similar to equation (5) for the eigenvlaues of A to beC = I. Relatively efficient methods for doing so have confined to a given region of the complex plane.been introduced [15, 16] ; they exploit the fact that

PA - ATP = S CONDITIONS FOR OSCILLATION

S is antisymmetric. Other methods for verifying Several investigators have sought to extend thestability include the Routh-Hurwitz criterion [14] single-degree-of-freedom notions of overdamping,and methods based on matrix inners [14]. Unfortu- critical damping, and underdamping to large systemsnately, the effort required to apply these tests is [26-30]. In particular, system equation (1) is under-comparable to that of calculating the eigenvalues in damped if all of the eigenvalues of A have nonvanish-the first place. ing imaginary parts; it is overdamped if all of the

imaginary parts vanish. Thus, an underdamped systemA sufficient condition for asymptotic stability of oscillates in all modes; an overdamped system tendssystem equation (1) is that D be positive definite. monotonically to the (asymptotic) state.

D >o The problem is trivial if the system can be writtenas n independent modes. This occurs if [31]

With K positive definite the Hamiltonian is a Lya-punov function. If D is semidefinite, asymptotic DM-'K KM-'D (6)

20- -

* III I I I I - _. -

in which case single-degree-of-freedom relations for Several contributions have involved oscillation condi-critical damping apply to each mode. For example, tions for distributed parameter systems. Relationsthe eigenvalues are all real if for 1 < j I n, analogous to equation (8) have been presented [37];

a critical surface approach has been developed [38].d >2/k,

J JSystem equation (1) with f = o has been transformed BOUNDS FOR FORCED RESPONSE[30] to read

It is well known that, if A is a stable matrix, system

+ V + Wy = o (7) equation (1) exhibits bounded inputbounded outputstability [39]. An apparently new estimate for the

with bound is presented below. Recall equation (3); thesolution z is given [1] by

V = M -/DM - / W = M-/- /z =exp(-At)z O + ft exp(-A(t-))g(7)dr. (10)

y = MV2x/(xHMx)2 Now A can be written as

The superscript H denotes the Hermitian transpose. A = SAS - '

The critical damping matrix A is defined by where A = diag(?,j(A)). It follows that

A = 2W / (8) norm(exp(-At)) = norm(S exp(-At)S-)

The system is underdamped if A - V is positive def- K i(S)norm(exp(-At))inite, critically damped if A - V = o, and overdampedif A - V is negative definite. The results have been •K(S)exp(-vt)used [32-33] to suggest design procedures. Severalmethods for computing the critical damping matrix wherehave been presented [34-351.

v min Re(Xj(A))An alternative method for designing overdamping Iinto a system has been discussed [36]. A relation and K (S) is the condition number of S.was derived for a critical surface in parameter spacesuch that each eigenvalue corresponding to a damping K (S) = norm (S) norm (Si).

rate lying below (above) the critical damping surfaceis complex (real). Suppose

The strongest results on overdamping have been norm (g) <3' t > 0.obtained [13] by a simple extension of certain prop-erties of symmetrizable matrices [20]. Specifically, Then from equation (10)the system equation (1) is overdamped if and onlyif A can be written as norm (z) norm (zo) + YeK(S) fo exp[-v(t--") dr

A = PQ (9) < norm (zo0) + 3' (S) /V 011)

P and Q are positive definite and Hermitian. An A bounded response obtains for unbounded inputselaborate argument using generalized inverses has such thatbeen formulated in order to determine P and 0. No ndesign applications of equation (8) have yet been norm (g)•3' +-72 exp(Mt)reported, where 1 < P.

-21

i " --

For the most part, the relationship in (11) is not at LOCALIZATION OF SYSTEM EIGENVALUESall sharp. Better results have been obtained [40-441for the special case in which f is oscillatory. There has been a fair amount of interest in the

question of approximate bounds on the real andf = fo exp liwt) imaginary parts of the eigenvalues of system equa-

tion (1). The Gershgoren theorem has been usedIf equation (6) holds, single-degree-of-freedom rela- [2, 461 to derive a circle in the complex plane con-tions immediately furnish [443 taining the system eigenvalues. Systems satisfying

equation (6) have been treated [27, 28]. In the

k. d 2 commonly assumed casek - . < -

no m m j -- mj. D = °M + OK

norm 1 the influence of ct and 0 on the eigenvalue locationsno W has been extensively examined [47, 481. Relatively

d , otherwise sharp enclosure relations were obtained [49] using.1 a shift in the eigenvalue spectrum togetner with the

extremal properties of eigenvalues.

where mj, dj, and kj denote the ordered eigenvalues Some new and apparently improved results areof M, D, and K; (i.e., m, > m2 .. > imn). presented here using the Cauchy-Schwartz inequality.

From equation (8) the eigenvalues X, can be written asIn the more general oscillatory input case in whichequation (6) fails, a theorem 145] has been extended X= -y Vy+ (yH Vy)2 - 4 yH Wy.[43] to obtain the best possible bounds in terms ofthe extreme eigenvalues v,, vn, w1 , wn of V and W Now by the Schwartz inequality,introduced in equation (7). Namely,

norm x, [mi min ~w; )]-ly H Wy > (y H W'/)2

norm (f) -- t)0 The imaginary part of A is subject to

(IMP)2 4yH Wy - (yH Vy)2where 2 stands for the parameters Pk, Pd, cos 6,cos 0 restricted such that 4 (y W y2 - (yH Vy)2

0 o<Pk < l1 O<Pd< 1 < [2y" W y -y Vy] [2yH W\+yHvy]

-1 <cose < 1 -1 <cos< 1< [y H(20 V)y] IyH(2w h+,J)y]

The quantity q is defined by

< P (21 - V) p (20 + V) (12)

q - (kn-, 2)2 +2 Pk(kn-w 2 )(k -kn) COS2

a

2kThe spectral radius p is defined by

+ k 2(k1-kn) 2Cos2 e + W 2dn2 p(Q) = max I

+ , 2d(- 2 2 2 2 2+ 2od w dn(dl-dn)cos 0 + Pd , (d 1 dn) COS 0

Unfortunately, for the real part the Schwartz inequal-+ 2upd Pk(kI-kn )(d -d n) cos 8 cos € sin e sin p. ity is of no avail. Instead, the best results we have

been able to derive are

22

R .- [Vn2 4wj1 , I2 4wn1 ] 6. Huseyin, K., "Vibrations and Stability of Me-Re A >" T" 2-max [ -chanical Systems, Part If," Shock Vib. Dig.,

(13.1) 12 (4) (1980).

Re X. < min [o, 0] (13.2) 7. Nayfeh, A. and Mook, D., Nonlinear Oscillations,Wiley Interscience (1979).

wherevn + 1 2 _ 2 L 8. Rouche, N., Habets, D., and Laloy, M., Stability

- + - - 4n Theory by Lyapunov's Direct Method, Springer-Verlag (1977).

Geometrically, the relationships given in (12, 13)define a rectangle in the complex plane that encloses 9. Atherton, D.P., Stability of Nonlinear Systems,

the system eigenvalues. Research Studies Press (1981).

10. Pusey, H., et al (eds.), An International Survey of

CONCLUSION AND DISCUSSION Shock and Vibration Technology, Shock andVibration Information Center (1981).

The literature has been reviewed on four aspects ofthe response of damped linear mechanical systems. 11. Wang, B.P. and Pilkey, W.D., "Optimal Damper

Considerable progress has been made in the last Location in the Vibration Control of Large

several years on oscillation conditions, forced re- Space Structures," Dynamics and Control of

sponse bounds, and eigenvalue localization. Large Flexible Spacecraft, Proc. 3rd VPI/AIAASymp. (1982).

Unfortunately, progress has been disappointing onderiving simple conditions on system matrices, less 12. Inman, D.J., "Oscillatory Damped Distributed

restrictive than positive definiteness, under which Parameter Systems," Mech. Res. Comm. (1982).

asymptotic stability obtains. The potential of newresults in vibration control settings is only beginning 13. Nicholson, D.W., "Overdamping of a Linear

to be realized. Mechanical System," (to appear in Mech. Res.Commun.).

REFERENCES 14. Jury, E.l., Inners and Stability of DynamicSystems, John Wiley and Sons, Inc. (1974).

1. Nicholson, D.W., "Stable Response of DampedL",15. Barnett, S. and Storey, C., Matrix Methods in- Linear Systems," Shock Vib. Dig., 12 (6) (1980).

Stability Theory, Barnes and Noble (1970).

2. Lancaster, P., Lambda Matrices and Vibrating 16. Fawzy, I., "A Simplified Stability Criterion forSystems, Pergamon Press (1966). Nonconservative Systems," J. AppI. Mech.,

i ~Trans. ASME, 4..6(1979).

3. Mller, P.C., Stabilit~it und Matrizen, Springer-

Verlag (1977). 17. Chetaev, N.J., The Stability of Motion, PergamonPress (1971).

4. Huseyin, K., Vibrations and Stability of MultipleParameter Systems, Sijthoff and Noordhoff 18. Willems, J.L., Stability Theory of Dynamical(1978). Syst Nelson (1970).

5. Huseyin, K., "Vibrations and Stability of Me- 19. Inman, D.J., "Dynamics of Asymmetric Non- Ychanical Systems, Part I," Shock Vib. Dig., & conservative Systems," Paper 83-APM-4 (to

(4) (1976). appear in J. Appl. Mech., Trans. ASME).

232

20. Taussky, 0., "Positive Definite Matrices and 33. Ahmadian, M. and Inman, D.J., "A ComputerTheir Role in the Study of the Characteristic Package for the Design of Damped Linear Multi-Roots of General Matrices," Adv. Math., 2 degree of Freedom Systems," Proc., Symp. Adv.(1968). Trends Struc. Solid Mech., NASA, Washington,

DC (Oct 1982).

21. Shapiro, E.Y., "On the Lyapunov Matrix Equa-tion," IEEE Trans. Auto Contr., AC-19 (1974). 34. Grey, J.A. and Andry, A.N., "A Simple Calcula-

tion for the Critical Damping Matrix of Linear22. Kwon, W.H. and Pearson, A.E., "A Note on the Multidegree of Freedom Systems" (to appear in

Algebraic Riccati Equation," IEEE Trans. Auto. Mech. Res. Commun.).Contr., AC-22 (1977).

35. Inman, D.J. and Orabi, I., "An Efficient Methoo

23. Bialas, S., "On the Lyapunov Matrix Equation," for Computing the Critical Damping Condition"IEEE Trans. Auto. Contr., AC 25 (1980). (to appear in J. Appl. Mech., Trans. ASME).

24. Nicholson, D W., "Eigenvalue Bounds for the 36. Beskos, D.E. and Boley, B.A., "Critical DampingLyapunov and Riccati Matrix Equations," IEEE in Linear Discrete Dynamic Systems," J. Appl.Trans. Auto. Contr., AC-26 (1981). Mech., Trans. ASME, 47 (1980).

25. Nicholson, D.W., "Eigenvalue Bounds for AB + 37. Inman, D.J. and Andry, A.N., "The NatureBAH, '" Mech. Res. Commun. (1982). of Temporal Solutions of Damped Distributed

Parameter Systems with Classical Normal Modes,"

26. Duffin, R.J., 'A Minimax Theorem for Over- ASME Paper 82-WA-APM-14 (to appear in J.damped Networks," J. Ratl. Mech. Anal., 4 Appl. Mech., Trans. ASME).(1955).

38. Beskos, D.E. and Boley, B.A., "Critical Damping27. Nicholson, D.W., "Eigenvalue Bounds for Damp- in Certain Linear Continuous Dynamic Systems,"

ed Linear Systems," Mech. Res. Commun., 5 Intl. J. Solids Struc., 47(1981).(1978).

39. Mtller, P.C., Forced Linear Vibrations, CISM

28. MJller, P.C., "Oscillatory Damped Linear Sys- Course 172, Springer-Verlag (1977).temns," Mech. Res. Commun., 6(1979).I

40. Nicholson, D.W., "On the Forced Vibration of a

29. Nicholson, D.W., "Comments on Damped Re- Damped Linear System," Mech. Res. Commun.,

sponse in Linear Systems," Mech. Res. Corn- 6(1979).

mun., 6 (1979). 41. M61ler, P.C., "Remar'ks on Vibrations of Damped

30. Inman, D.J. and Andry, A.N., "Some Results on Linear Systems," Mech. Res. Commun., 6(1979).

the Nature of Eigenvalues of Discrete DampedSystems," J. AppI. Mech., Trans. ASME, 47 42. Nicholson, D.W., "Bounds on the Forced Re-

(1980). sponse of Damped Linear Systems," Mech. Res.Commu n., 7 (1980).

31. Caughey, T.K. and O'Kelly, M.E.J., "ClassicalNormal Modes in Damped Linear Dynamic 43. Nicholson, D.W., "Response Bounds for Asymp-Systems," J. Appl. Mech., Trans. ASME, 32 totically Stable Time-Invariant Linear Dynamical

(1965). - Systems," IEEE Trans. Auto. Contr., AC-27

(1982).32. Inman, D.J. and Andry, A.N., "A Procedure for

Designing Overdamped Lumped Parameter Sys- 44. Nicholson, D.W., "Forced Vibrations of a Largetems," Shock Vib. Bull., U.S. Naval Res. Lab., Damped Mechanical System," Shock Vib. Bull.,Proc. 52 (1982). U.S. Naval Res. Lab., Proc. 52 (1982).

24

45. Strang, G., "Eigenvalues of Jordan Products," 48. Schneider, J., "Beeinflssung der EigenwerteAmer. Math. Month (1962). von Schwingungssystemen mit Modaler Dgmp-

fung," Ing.-Arch., 48 (1979).46. Schneider, J., "Der Satz von Gerschgoren fJr

Gedampfte Schwingungen," Z. angew. Math. 49. Schneider, J., "Einschliessung der EigenwerteMech., M (1980). Modifizierter Gedampften Schwingungssysteme,"

Acta Mech., 40 (1981).47. Falk, S., "Eigenwerte Gedampfter Schwingungen

bei Gultigkeit der Bequemlichkeitshypothese,"Ing.-Arch.,_47 (1978).

It_

' 4-

BOOK REVIEWS

DIGITAL SIGNAL PROCESSING Chapter 5 treats the relationship between analog

AND TIME SERIES ANALYSIS and digital systems. Chapter 6 considers the designof MA, ARMA, and least squares design of MA

E.A. Robinson and M.T. Silvia filters.

Holden-Day, Inc., San Francisco, CA1979, 411 pp Chapter 7 treats cepstrum, the Laplace Z transform,

convolution, and reverse and inverse sequences ofminimum delay. The reviewer believes that this

The use of digital signal processing has required new chapter should have been placed after the sections on

methods and procedures. Both the analyst and random processes, which are contained in Chapter 8.

designer of digital processing equipment must be Stationary random processes, auto- and cross-correla-

familiar with a number of mathematical topics. tion functions, and cumulative distributions are

As stated by the authors, "We have co-written the covered. Chapter 9 is concerned with spectral estima-

book in a form of a standard mathematics textbook tion -- periodogram, white noise, and gaussian and

in the following sense. The book is self-contained and chi-square distributions. The cosine-squared window

all concepts are defined in mathematical terms as is considered, but no mention is made of Hanning,

they are introduced." At times the mathematical Parzen, Goodman, or cosine taper log windows. The

format makes the book difficult to follow. The book reviewer believes the chapter is too brief to do

contains 11 chapters, each of which is divided into a justice to the general theory of random processes.

number of sections.Chapter 10 focuses upon seismic deconvolution; i.e.,exploration for oil and natural gases employing ran-

Chapter 1 considers complex variables and phasors, doml roc Th o n d in g a e r e fly di-

including Taylor and Laurent series. Chapter 2 dis-

cusses digital signals, finite differences, difference cusses speech deconvolution.

equations, and impulse response and convolution; The authors have slanted the book toward electrical Ia classification of digital systems is given. The classi-

ficaionis ompsed f atorcurive AR) moing engineering and the design of special-purpose hard-fication is composed of autorecursive (AR), moving ware for processing electrical signals. Information onaverage (MA), and autorecursive moving average applied time series analysis is minimal, and the

(ARMA). ARMA is seldom used in engineering appli- bookicontin s no c u ms.

cations but should become more important in future

years. This volume is not meant for casual reading. The

reviewer believes that the authors should expand theChapter 3 explains the transfer function via Taylor book and incorporate the applied aspects of randomand Laurent series and Laplace Z transforms. The processes. No mention is made of partial coherencechapter concludes with a discussion of ARMA and its or industrial applications of stochastic methods. Theapplication to digital signal analysis. book should be supplemented by the volume entitled,

Applied Time Series Analysis by Enochson andChapter 4 is the heart of the book. Fourier transform Otnes, which has been reviewed in the Digest.of digital signals is described - including Fouriertransforms, finite Fourier transforms (FFT), and H. SaundersFFT. The reviewer believes that the authors should General Electric Companyhave included computer programs and applications Bldg. 41, Room 307in the FFT section. Schenectady, NY 12345

26

1.

DIGITAL FOUNDATIONS OF TIME Ten appendices discuss methods for solving simul-SERIES ANALYSIS--THE BOX-JENKINS taneous equations, determinant and matrix theory,

APPROACH Cramer's rule, eigenvalues, eigenvectors, and orthog-onal matrices.

E.A. Robinson and MT. Silvia

Holden-Day, Inc., San Francisco, CA This is one of the better books on time series analysis.

1979, 451 pp The main shortcoming of this volume is the absenceof both computer programs and applied types ofproblems. Inclusion of both would enhance the

The book consists of five chapters and two appen- book. The reviewer does recommend this book to

dices. those interested in time series analysis It is a goodintroduction to the more abstract aspects of the BJ

Chapter 1 expresses time series analysis in terms of approach.

probability, random variables, arithmetic, and geo-metric smoothing. Chapter 2 treats the linear regres- H. Saunders

sion model. Some of the terms are used in stochastic General Electric Company

analysis -- expected values, variance, covariance, Gaus- Bldg. 41, Room 307

sian distributions, and least square estimates. Also Schenectady, NY 12345

included are tests of significance for regression coeffi-cients, Gaussian multipliers, and variance and covari-ance for empirical regression coefficients. The chapter APPLICATIONS OF FUNCTIONALconcludes with an interesting discussion of the ANALYSIS IN ENGINEERINGcondition of variance of error at a sample point and

unbiased estimate of u2

. J.L. NowinskiPlenum Press, New York, NY

Chapter 3 has to do with multiple regression. Topics 1981,304 pp, $37.50

include matrix representation of sample observations,

least square estimates in the multiple sense, tests ofsignificance for regression functions and coefficients, The introduction states that the text is an attemptand multiple and partial correlations. Other topics to close the present gap between books on theare orthogonality, sequential combination, and mathematical aspects of functional analysis andexpectation of explained and unexplained sums of its applications to mechanics. In the last two decadessquares. researchers in various areas of applied mechanics have

utilized successfully the methods of functional analy-Chapter 4 is concerned with linear systems. The sis in problems dealing with nonlocal continuumauthors describe the convolution theorem and trans- mechanics, nonlinear viscoelasticity, and finiteforms, auto and cross correlation, feedback stability, element analysis. Increasing interest in applicationsapproximate deconvolution, shaping and spiking has made it mandatory for the analytically-orientedfilters, and rational approximations. The reviewer engineering scientist to be formally exposed to thewas disappointed that few practical applications were elements of functional analysis so that he will becovered, able to use it quickly. The text under review fulfills

Chapter 5 treats the Box-Jenkins (BJ) approach to that need admirably.

time series analysis The authors introduce auto- This monograph was written by a well-known re-regression (AR) and moving average (MA). They searcher in mechanics whose recent contributionscombine the two and call the combination the mixed include the use of functional analysis. This strength-autoregressive moving average (ARMA) process. ens his perspective as to what the aim of the bookARMA, which has only recently appeared in seismic should be.analysis, permits greater flexibility in the fitting ormodeling of time series. The chapter concludes with The first five chapters contain introductory material

nonstationary processes and forecasting. on basic topics. They cover the distinction between

27

. !,4

physical and abstract spaces, basic vector algebra, INDUSTRIAL NOISE CONTROLdot product and length of a vector and generalizationof these values to inner product and norm, linear B. Fader

independence, and Euclidean spaces of many dimen- John Wiley & Sons, New York, NY

sions. The next five chapters extend the concepts 1981,251 pp, $30.95

developed to infinite-dimensional spaces. The topicsrange from infinite-dimensional Euclidean spaces toHilbert spaces and function spaces and their geom- This book was written with the intent of educating

etry. Applications are made to the bending and those with a need to cope with immediate noise

torsion of isotropic plates and bars, variational problems and "show you how to do that." In this

principles, and the theorems of Rayleigh-Betti and reviewer's opinion the author has succeeded. He

Clapeyron. points out that this is not the first book written onnoise control. The emphasis of the book is the work-

The final chapters are oriented toward applications; ing methods used in industrial noise control. The

all of the examples are given under headings that author mentions that the book is the result of sud-

pertain to the major topics of functional analysis. denly being told that he was in charge of noise con-

The methods involve finding bounds and establishing trol and having to live up to that responsibility.

inequalities for various problems in elasticity, appli- The chapter titles are:cation of the hypercircle method, and the methodof orthogonal projections. The direct methods of 1. What is Sound?Rayleigh-Ritz and Trefftz in the calculus of varia- 2. The Quality of Soundtions are considered within the context of functional 3. Decibelsanalysis, as are various other variational methods. 4. InstrumentsThe text ends with a brief chapter on the theory of 5. Measurementdistributions and Sobo(ev spaces. 6. Absorption - The General Idea

7. Using Absorption and Special AbsorbersAnswers to a number of illustrative problems are 8. Single-Wall Transmission Lossprovided; an extensive list of references will also help 9. Enclosures, Double Walls, Barriersthe reader to broaden the scope of his particular 10. Mufflers, Silencers, Lined Ductsarea of interest. 11. Vibration Isolation

12. DampingThis book is not elementary and cannot be read 13. Bringing Things TogetheIwithout concentration on the subject matter. The

patience of those readers who are willing to put The five five chapters cover the fundamentals neces-forth the effort will be amply rewarded however. sary to understand noise and its control. These in-In the opinion of this reviewer, the information clude instrumentation and their uses in making andgained will far exceed the effort made to acquire it. interpreting measurements. Other basics include

absorption, use of silencers, enclosures, and vibrationL.Y. Bahar isolation. The chapter on damping could be more

Department of Mechanical complete, but it gives the reader information aboutEngineering and Mechanics the different types available as well as when damping

Drexel University is effective. The last chapter presents a case historyPhiladelphia, PA 19104 of a noise control program undertaken to meet OHSA

requirements.

The book is designed to give the reader the necessaryinformation to get a job done with minimal theory

and math. Typical situations are used to emphasize /6concepts. The basic theory that is presented is appliedin many practical examples to reinforce key points.The English system of units is used throughout.

28

=I

The book is interestingly written and easy to follow.It is recommended particularly for the novice who,with some practice, will be able to cope successfullywith situations in which noise control is important.Even the more experienced professional should findthis text useful and will want a copy.

V.R. Miller5331 Pathview Drive

Huber Heights, OH 45424

29

I

SHORT COURSES

DECEMBER This course will concentrate upon equipments andtechniques, rather than upon mathematics andtheory.

SCALE MODELING IN ENGINEERING DYNAM- Contact: Wayne Tustin, 22 East Los Olivos Street,DtS DSanta Barbara, CA 93105 - (805) 682-7171.Dates: December 5-9, 1983

Place: Washington, D.C.Objective: The course will begin with a drop testdemonstration of damage to model and prototypecantilever beams made from different materials. JANUARYThese tests help to introduce the concepts of simi-larity and of physical dimensions which are prelimi-nary to any model analysis. Formal mathematicaltechniques of modeling will then be presented in- LECTURE/TRAINING COURSE ON NAVALcluding the development of scaling laws from bothdifferential equations and the Buckingham Pi Theo- Dates: January 9-13, 1984rem. A number of sessions then follow wherein the Place: San Diego, CAinstructors present specific analyses relating to a Objective: Combat survivability is a key issue in thevariety of dynamic vibrations and transient response design of naval ships. Current DoD policy highlightsproblems. The problems are selected to illustrate the survivability as an essential requirement in the shipuse of models as an analysis tool and to give examples acquisition process. The wars in South East Asia,of variations on different modeling techniques. the Middle East and, recently, in the Falkland IslandTypes of problems presented include impact, blast, conflict accentuated the need for combat surviv-fragmentation, and thermal pulses on ground, air and ability. Since shock induced by various weapons is afloating structures. major and highly destructive weapon effect, design IContact Wilfred E. Baker, Southwest Research for survival under shock is a vital part of the ship

survivability process. Hence, under present NavyInstitute, P.O. Box 28510, San Antonio, TX 78284 - policy, all mission-essential equipment must qualify(512) 684-5111, E xt. 2303. to rigorous shock hardening requirements. Naval

Systems Commands and Laboratories, shipbuilders4I and equipment suppliers all play a role in the shock

VIBRATION AND SHOCK SURVIVABILITY, hardening process. If you work for the Navy, youTESTING, MEASUREMENT, ANALYSIS, AND may be involved in the implementation and verifi-CALIBRATION cation of the Navy shock requirements, or you mayDates: December 5-9, 1983 be responsible for the purchase of electronic orPlace: Santa Barbara, California weapon systems that must be shock qualified. As anDates: February 6-10, 1984 employee of a major shipbuilder or a Naval equip-Place: Santa Barbara, California ment supplier, you may be faced with broad and/orDates: March 5-9 1984 specific aspects of Naval shock design. This lecture/Place: Washington, D.C. training course has been developed to help engineers,Objective: Topics to be covered are resonance and scientists, Naval architects and others understand andfragility phenomena, and environmental vibration and effectively deal with the U.S. Navy's ship shockshock measurement and analysis; also vibration and hardening requirements. If you are faced with shipshock environmental testing to prove survivability, shock problems, participation in this course should

30

II'

increase your value to your organization and enhance Dates: August 14-17, 1984your own career advancement. Place; New Orleans, Louisiana

Dates: November 13-16, 1984Contact: Henry C. Pusey or Maurisa Gohde, NKF Place: Cincinnati, OhioEngineering Associates, Inc., 8150 Leesburg Pike, Objective: In this four-day course on practicalSuite 700, Vienna, VA 22180 - (703) 442-8900. machinery vibration analysis, savings in production

losses and equipment costs through vibration analysisand correction will be stressed. Techniques will be

MACHINERY VIBRATION ENGINEERING reviewed along with examples and case historiesDates: January 24-27, 1984 to illustrate their use. Demonstrations of measure-Place: Houston, Texas ment and analysis equipment will be conductedDates: July 17-20, 1984 during the course. The course will include lecturesPlace: Oak Brook, Illinois on test equipment selection and use, vibration mea-Dates: November 27-30, 1984 surement and analysis including the latest informa-Place: Washington, D.C. tion on spectral analysis, balancing, alignment, iso-Objective: Techniques for the solution of machinery lation, and damping. Plant predictive maintenancevibration problems will be discussed. These tech- programs, monitoring equipment and programs, andniques are based on the knowledge of the dynamics equipment evaluation are topics included. Specificof machinery; vibration measurement, computation, components and equipment covered in the lecturesand analysis; and machinery characteristics. The include gears, bearings (fluid film and antifriction),techniques will be illustrated with case histories shafts, couplings, motors, turbines, engines, pumps,involving field and design problems. Familiarity with compressors, fluid drives, gearboxes, and slow-speedthe methods will be gained by participants in the paper rolls.workshops. The course will include lectures onnatural frequency, resonance, and critical speed Contact: The Vibration Institute, 101 West 55thdetermination for rotating and reciprocating equip- Street, Suite 206, Clarendon Hills, IL 60514 - (312)ment using test and computational techniques; equip- 654-2254.ment evaluation techniques including test equipment;vibration analysis of general equipment includingbearings and gears using the time and frequency DYNAMIC BALANCING SEMINAR/WORKSHOPdomains vibratory forces in rotating and recipro- Dates: February 22-23, 1984cating equipment; torsional vibration measurement, March 21-22, 1984analysis, and computation on systems involving en- April 18-19, 1984gines, compressors, pumps, and motors; basic rotor May 23-24, 1984

dynamics including fluid film bearing characteristics, Place: Columbus, Ohiocritical speeds, instabilities, and mass imbalance Objective: Balancing experts will contribute a seriesresponse; and vibration control including isolation of lectures on field balancing and balancing machines.and damping of equipment installation. Subjects include: field balancing methods; single, two

and multi-plane balancing techniques; balancingContact: The Vibration Institute, 101 West 55th tolerances and correction methods. The latest in-placeStreet, Clarendon Hills, IL 60514 - (312) 654-2254. balancing techniques will be demonstrated and used

in the workshops. Balancing machines equipped with

microprocessor instrumentation will also be demon-FEBRUARY strated in the workshop sessions, where each student

will be involved in hands-on problem-solving usingactual armatures, pump impellers, turbine wheels,

MACHINERY VIBRATION ANALYSIS etc., with emphasis on reducing costs and improvingDates: February 21-24, 1984 quality in balancing operations. ./

Place: San Francisco, CaliforniaDates: May 15-18, 1984 Contact: R.E. Ellis, IRD Mechanalysis, Inc., 6150Place: Nashville, Tennessee Huntley Rd., Columbus, OH 43229 - (614) 885-5376.

31

MARCH APRIL

MEASUREMENT SYSTEMS ENGINEERING ROTOR DYNAMICSDates: March 12-16, 1984 Dates: April 30 -May 4, 1984Place: Phoenix, Arizona Place: Syria, VirginiaMEASUREMENT SYSTEMS DYNAMICS Objective: The role of rotor/bearing technology inDates: March 19-23, 1984 the design, development and diagnostics of industrialPlace: Phoenix, Arizona machinery will be elaborated. The fundamentals ofObjective: Program emphasis is on how to increase rotor dynamics; fluid-film bearings; and measure-productivity and cost-effectiveness for data acquisi- ment, analytical, and computational techniques willtion groups in the field and in the laboratory. The be presented. The computation and measurementprogram is intended for engineers, scientists and of critical speeds vibration response, and stability ofmanagers of industrial, governmental and educational rotor/bearing systems will be discussed in detail.organizations who are concerned with planning, Finite elements and transfer matrix modeling willexecuting, or interpreting experimental data and be related to computation on mainframe computers,measurements. The emphasis is on electrical measure- minicomputers, and microprocessors. Modeling andments of mechanical and thermal quantities, computation of transient rotor behavior and non-

linear fluid-film bearing behavior will be described.Contact: Peter K. Stein, Director, Stein Engineer- Sessions will be devoted to flexible rotor balancinging Services, Inc., 5602 East Monte Rosa, Phoenix, including turbogenerator rotors, bow behavior,AZ 85018 - (602) 945-4603/946-7333. squeeze-film dampers for turbomachinery, advanced

concepts in troubleshooting and instrumentation,and case histories involving the power and petro-chemical industries.

Contact: Dr. Ronald L. Eshleman, Vibration Insti-tute, 101 W. 55th Street, Suite 206, Clarendon Hills,I L 60514 - (312) 654-2254.

3,'6

32

news on current

NEWS B IEF "and Future Shock andN EW S B RIEF a Vibration activities and events

Call for Papers The USNC/TAM has been charged with the task ofevaluating all U.S. contributed papers. The evaluation

XVIth INTERNATIONAL CONGRESS OF is in the hands of a committee chaired by Prof.THEORETICAL AND APPLIED MECHANICS Shields. The committee will be assisted by a fairly

August 19-25, 1984 large number of reviewers representing diverse areasLyngby, Denmark of mechanics of fluids and solids. The resulting

evaluation will then be used by the InternationalThe United States National Committee on Theoreti- Papers Committee as a guide for the final selection.cal and Applied Mechanics has announced plans for Authors will be notified in May 1984 about thethe XVIth International Conference of Theoretical decision regarding their papers.and Applied Mechanics. The Congress encompassesthe entire field of analytical, solid, and fluid mechan- The USNC/TAM is also making an effort to obtainics, including applications, funds in order to provide some travel assistance for

U.S. participants in the International Congress inThere will be an opening lecture and a closing lecture, Lyngby. Further details regarding this will be an-

as well as a number of invited sectional lectures of nounced at a later date. Participants desiring informa-

more specialized nature. The International Congress tion on travel support should notify: Mr. Richard Y.

Committee has invited a number of distinguished Dow, Staff Officer, USNC/TAM, National Researchscientists to present these lectures. Council, 2101 Constitution Avenue, N.W., Washing-

ton, DC 20418.

Up to 540 contributed papers will be presented aslectures (approximately 270) and in poster/discussionsessions. Call for Papers

VIBRATION DAMPING WORKSHOPWithin the framework of the Congress the following February 27-29. 1984

three special topics will receive particular attention: Queen Mary Hotel

* micro-level studies of properties of multi- Long Beach, California

component media The Vibration Damping Workshop will provide a" marine-structure wave interaction, and forum for the latest state-of-the-art technology as* development of chaotic behaviour in dynamical well as selected tutorial information. Viscoelastic

systems property measurement and representation, high-

damped-metals, friction damping, damping in com-Each of these topics is interdisciplinary in the sense posites, analysis and design, applications, experimen-that it is intended to cover solid as well as fluid as- tal verification, controls-structure-interaction, andpects. Convenors have been appointed to coordinate payoff/benefits are topics to be covered. The statusthe lectures and other activities of each special ses- of U.S. Air Force funded contracts on the Dampingsion. Initial lectures are intended to have an instruc- Design Guide, Passive and Active Control of Spacetional element. Structure (PACOSS) and Reliability of Satellite

Equipment in a Vibroacoustic Environment (REL-Procedures for submitting papers may be obtained SAT) contracts will be reviewed.from: Prof. Richard T. Shield, 212 Talbot Labora-tory, Dept. of Theoretical and Applied Mechanics, Abstracts/papers and the desired length of timeUniversity of Illinois, Urbana, IL 61801. for presentation should be sent to the Sponsor:

33

4- --

Dr. Lynn Rogers, AFWAL/FIBA, Area B, Bldg. 45, 0 mechanical design applications including social,Room 257, Wright-Patterson AFB, OH 45433- (513) economic, and legal aspects255-5664. 0 CAD/CAM systems

0 hardware/software systems evaluation

Registration packets are available from the Adminis- * finite element analysestrative Chairman: Mrs. Audrey G. Sachs, University 0 intelligent machines and roboticsof Dayton Research Institute, KL 542, 300 CollegePark Avenue, Dayton, OH 45469 - (513) 229-2919. Four copies of each manuscript and the original

drawings must be submitted for review by Febru-

ary 15, 1984, Papers accepted for the conference andpublished as ASME pamphlets will be preprinted

Call for Papers from final mats prepared by the authors. Thesestandard mats will be provided to authors soon after

1984 DESIGN AUTOMATION CONFERENCE acceptance of their papers Each accepted paper willOctober 7-11, 1984 also be reviewed for possible publication in the

Cambridge, Massachusetts ASME Journal of Mechanisms, Transmissions andAutomation in Design and/or Mechanical Engineer-

The 10th Design Automation Conference will be held ing.in conjunction with the 18th Mechanisms Conferenceon October 7-11, 1984 at the Hyatt Regency Hotel Manuscripts should be submitted to: Professor Panosin Cambridge, Massachusetts. These conferences are Papalambros (Papers Review Chairman), Mechanicalsponsored by the Design Engineering Division of the Engineering and Applied Mechanics, The UniversityAmerican Society of Mechanical Engineers. of Michigan, Ann Arbor, MI 48109 - (313) 763-

1046.The ASME Design Automation Committee invitesauthors to submit papers in the broad areas of design The deadline for international contributions isand automation including: January 15, 1984.

* man-machine interaction Interested parties are encouraged to forward sugges-* computer graphics and drafting tions for session themes and/or panel discussion0 optimization and numerical methods topics to the above committee member.

C

4

t ",

34•

ABSTRACTS FROMTHE CURRENT LITERATURE

Copies of publications abstracted are not available from SVIC or the Vibration Institute, except those generatedby either organization. Government Reports (AD-, PB-, or N-numbers) can be obtained from NTIS, Springfield,Virginia 22151; Dissertations (DA-) from University Microfilms, 313 N. Fir St., Ann Arbor, Michigan 48106;U.S. Patents from the Commissioner of Patents, Washington, DC 20231; Chinese publications (CSTA-) in Chineseor English translation from International Information Service Ltd., P.O. Box 24683, ABD Post Office, HongKong. In all cases the appropriate code number should be cited. All other inquiries should be directed to libraries.The address of only the first author is listed in the citation. The list of periodicals scanned is published in issues1,6, and 12.

ABSTRACT CONTENTS

MECHANICAL SYSTEMS .... 36 MECHANICAL COMPONENTS. 44 DYNAMIC ENVIRONMENT... 59

Rotating Machines ....... 36 Absorbers and Isolators . . .44 Acoustic Excitation ...... 59Reciprocating Machines . . . 37 Springs .............. 46 Shock Excitation ........ 63Power Transmission Tires and Wheels ........ 46 Vibration Excitation ..... 64

Systems ........... 38 Blades ............... 47Electromechanical Systems.38 Bearings .............. 47 MECHANICAL PROPERTIES. .67Materials Handling Gears ............... 48

Equipment......... 38 Fasteners ............. 49 Damping ............. 67Valves ............... 51 Fatigue ............... 69Seals ................ 51 Elasticity and Plasticity . .. 69

Wave Propagation ....... 70STRUCTURAL SYSTEMS .. .. 39

EXPERIMENTATION ....... 71Buildings .......... . 39 Measurement and Analysis . 71

Foundations ........... 39 Cables ............... 51 Dynamic Tests ......... 75Harbors and Dams ....... 40 Bars and Rods .......... 52 Diagnostics ............ 76Power Plants .......... 40 Beam s ............... 52 Balancing ............. 77Off-shore Structures ...... 40 Cylinders ............. 53 Monitoring ............ 77

Frames and Arches ...... 54Plates ............... 54 ANALYSIS AND DESIGN .... 77

VEHICLE SYSTEMS ........ 41 Shells ............... 56Rings ............... 56 Analytical Methods ...... 77

Ground Vehicles ........ 41 Pipes and Tubes ........ 56 Parameter Identification ... 80

A ircraft ............. 41 Ducts ............... 57 Design Techniques ....... 81

Missiles and Spacecraft .... 43 Building Components ..... 58 Computer Programs ...... 81

GENERAL TOPICS ......... 83

BIOLOGICAL SYSTEMS ..... 44 ELECTRIC COMPONENTS . . .58 Criteria, Standards, andSpecifications ....... 83

Human .............. 44 Generators ............ 58 Bibliographies .......... 83

35J

MECHANICAL SYSTEMS 83-2137Free Wake Techniques for Rotor AerodynamicAnalysis. Volume 2: Vortex Sheet ModelsA. TanuwidjajaMassachusetts Inst. of Tech., Cambridge, MA, ReptNo. NASA-CR-166435, 162 pp (Dec 1982)

ROTATING MACHINES N83-19712(Also see Nos. 2145, 2270,2314,2323,2324, 2354)

Key Words: Rotors, Aerodynamic loads, Fluid-inducedexcitation

83-2135 Results of computations are presented using vortex sheets

Instability of Rotors in Fluid Film Bearings to model the wake and test the sensitivity of the solutionsJ S. Rao to various assumptions used in the development of the

Stress Technology, Inc,, Rochester, NY, J. Vib. models. The complete codings are included.

Acoust. Stress Re!. Des., Trans. ASME, 105 (5), pp274-279 (July 1983) 9 figs, 10 refs

Key Words: Rotors, Fluid-film bearings, Whirling, Oil whip 83-2138phenomena Free Wake Techniques for Rotor Aerodynamic

This paper is concerned with instability of a rotor that arises Analysis. Volume 3: Vortex Filament Modelsdue to fluid film forces of a journal bearing. The half fre- M. Browerquency whirl and the resulting oil whip phenomena is ex- Massachusetts Inst. of Tech., Cambridge, MA, Rept.plained by a consideration of flow balance in a bearing which No. NASA-CR-166436, 69 pp (Dec 1982)loses the load carrying capacity. The threshold instabilitycriterion for a rigid rotor in plain cylindrical bearings is N83-19713given in the form of a chart by obtaining the solution ofequations of motion with the corresponding spring and Key Words: Rotors, Aerodynamic loads, Fluid-induced exci-damping coefficients. Both translatory and conical whirls tationare considered. The analysis is then presented for a flexiblerotor and a simple procedure is given to obtain the insta- Results obtained using a vortex filament model, as opposedbility threshold speed based on the rigid rotor criterion, to sheets are discussed, against using various modeling tech-

niques and including the computer codings.

83-2136Free Wake Techniques for Rotor Aerodynamic 83-2139Analysis. Volume 1: Summary of Results and Back- Forward Velocity Effects on Fan Noise and theground Theory Influence of Inlet Aeroacoustic Design as MeasuredR.H Miller in the NASA Ames 40 x 80 Foot Wind TunnelMassachusetts Inst. of Tech., Cambridge, MA, Rept. R.G. Holm, L.E. Langerbrunner, and E.O. McCannNo. ASRL-TR-199-1, NASA-CH-166434, 48 pp General Electric Co., Cincinnati, OH, Rept. No.(Dec 1982) NASA-CR-166461, 188 pp (July 1981)N83-19711 N83-20709

Key Words: Rotors, Aerodynamic loads, Fluid-induced exci- Key Words: Fans, Turbofans, Fan noise, Noise reductiontation

The inlet radiated noise of a turbofan engine was studied.

Results obtained during the development of a consistent The principal research objectives were to characterize oraerodynamic theory for rotors in hovering flight are dis- suppress such noise with particular regard to its tonal char-cusaed. Methods of aerodynamic analysis were developed acteristics. The major portion of this research was con-which are adequate for general design purposes until such ducted using ground-based static testing without simulation

time as more elaborate solutions become available, in particu- of aircraft forward speed or aircraft installation-related Ular solutions which include real fluids effects. aeroacoustic effects.

36

83.-140 phase converter is considered. Instantaneous symmetrical

On the Transient Interaction of Centrifugal Compres- components are used in modeling the motor with differentsrs and Their Piping Systems stator connections, including the external capacitor. Digital

simulation studies are carried out for the system consideredC.R. Sparks and results are presented and discussed.

Southwest Res. Inst., San Antonio, TX, ASME PaperNo. 83-GT-236

Key Words: Compressors, Centrifugal compressors, Pipingsystems

83-2143This paper provides some new and significant findings on the Measurement of the Acoustic Internal Source Im-dynamic interaction of centrifugal compressors with piping pedance of an Internal Combustion Enginesystems and describes the basic phenomena underlying these D.F. Ross and M.J. Crockerinteractions. Ray W. Herrick Labs., School of Mech. Engrg., Pur-

due Univ., West Lafayette, IN 47907, J. Acoust.Soc. Amer., 74 (1), pp 18-27 (July 1983) 23 figs,36 refs

83-2141Component Synthesis of Multi-Case, Rotating Ma- Key Words: Internal combustion engines, Acoustic imped-

chinery Trains by the Generalized Receptance Ap- ance, Test facilities, Measurement techniques, Experimental

proach test data

A.B. Palazzolo, B.P. Wang, and W.D. Pilkey The standing wave tube technique has been adapted to

Southwest Res. Inst., San Antonio, TX, ASME Paper measure the acoustic internal source impedance of an in-

No. 83-GT-229 ternal combustion engine. In order to implement this tech-nique an extensive experimental facility was designed and

Key Words: Rotating machinery, Component mode synthe- constructed and simple test cases were evaluated for validity.

sis In addition an adaptation of the standing wave tube meth-od incorporating a random signal as the external driver sound

A method is presented for computing the eigenvalues of source and digital data analysis techniques were introduced

multicase, coupled, rotating machinery trains. The method to reduce the experimental difficulty and time consumption.

is based on a synthesis technique that uses generalizedreceptance formulas previously derived by the authors. Theseformulas improve the accuracy of the computed receptanceswhen only an incomplete set of modes is available. I

83-2144Noise Analysis and Control in Fluid Power Systems.

RECIPROCATING MACHINES Part 5: Noise Radiated from Components - Piston(Also see No. 2339) and Gear Pumps

H.R. Martin3.42Univ. of Waterloo, Waterloo, Ontario, Canada,

83-2142 Hydraul. Pneumat., 36 (6), pp 60-64 (June 1983)Transient Analysis of a Three Phase Induction Motor 5 figs, 6 refswith Single Phase SupplyS.S. Murthy, G.J. Berg, B. Singh, C.S. Jha, and B.P. Key Words: Pumps, Noise generation, Sound propagationSinghUniv. of Calgary, Calgary, Canada, T2N 1N4, IEEE All positive displacement pumps move discrete blocks of

fluid from the inlet port to the outlet port of the pump.Trans., Power Apparatus Syst., PAS-102 (1), pp As this process is periodic in nature, most of the radiated28-37 (Jan 1983) 11 figs, 2 tables, 9 refs noise energy is associated with the fundamental pumping

frequency and its harmonics. This part of the noise is radi-Key Words: Induction motors, Transient response ated partly through the pump casing and partly as pressure

fluctuations in the delivery line. In addition, broadband VThe transient behavior of a three phase induction motor noise from flow turbulence is superimposed on the periodicoperating with single phase supply and using capacitors as noise.

37--

83-2145 ELECTROMECHANICAL SYSTEMSA Theoretical and Experimental Study of Hydraulic (See Nos. 2248, 2249, 2250)

Power Supplies Using Pressure-Compensated Pumps,Their Influence on Servosystem Dynamic Response,and Their Utilization in Energy-Saving ConfigurationsA. Pery MATERIALS HANDLING EQUIPMENTPh D. Thesis, Ohio State Univ., 499 pp (1983)DA8311788

83-2147Key Words: Pumps, Hydraulic systems, Servomechanisms, Noise Reduction at Vibrating Feeders (Lirmind-Computer programs, Frequency domain method. Time do- erung an einem Vibrationsfrderer)main method G. Rau

Maschinenbautechnik, 32 (5), pp 219-222 (1983)Most valve controlled servosystem analyses assume constant _3p

supply pressure. When servo transients are large and fast 9 figs, 3 tables, 3 refs

enough, a pressure compensated pump type of supply, with- (In German)

out accumulator, can no longer maintain reasonably constantsupply pressure and pump dynamics become significant. Key Words: Conveyors, Vibratory techniques, Noise reduc-Combined pump/servosystem dynamics was studied analyti- tioncally and experimentally tested. Both linearized and non-linear system models were formulated. A useful subsystem The electromagnetic excitation of vibrating feeders causesmodeling technique was developed. Computer programs were noise with a low freuqency which is predominantly emitteddeveloped in both time domain and frequency domain, from the coating and feeding container. If the feeding mate-Experimentally, step response performance was evaluated in rials (metal parts) strike the vibrator conveyor a high-fre-terms of controlled variable maximum overshoot, frequency quency noise is additionally generated. The optimizationof oscillations and time to peak. Frequency tests were per, of the tested different noise control measurements resultformed investigating three transfer functions, in a noise reduction of the feeder by about 26 dB(A).

83-2148

POWER TRANSMISSION SYSTEMS Transient Torque Produced in Main Shaft of ElectricHoist During Motor Start-Up and Emergency BrakeOperationsA. Futakawa, N. Muramatsu, K, Takeya, and F.Ishidla

Central Res. Lab., Mitsubishi Electric Corp., Amaga83-2146 saki, Hyogo, Japan, J. Vib. Acoust. Stress Rel. Des.,Dynamic Behavior of Hydraulic Magnets under Trans. ASME, 105 (1), pp 17-23 (Jan 1983) 13 figs,Service Conditions (Dynamiaches Verhalten von 4 refsHydraulikmagneten unter Betriebsbedingsngen)M Seitz Key Words: Hoists, Shafts, Transient response, Start-up

TH 1lmenau, Sektion Geratftechnik, Germany, response, Braking effectsFeingeratetechnik, 32 (5), pp 199-202 (1983) 11figs, 3 refs The purpose of this study is to clarify the generation mech-

anism of the transient torque produced in the main shaftIn German) of an electric hoist. A mathematical model with three degrees

of freedom is proposed for the transient motion analysis ofKey Words: Hydraulic systems, Power transmission systems an electric hoist when lifting a weight and application of an

emergency brake. A technique is developed for measuringA number of hydraulic systems are employed for driving and the transient torque of a main shaft and the transient tensioncontrol of machinery. The dynamic response of hydraulic of a wire rope. Comparing theoretical with experimentalmagnets during starting and service conditions is presented results, the generation mechanism of the trauisient torque -1and the possibilities for the determination of hydraulic produced in the main shaft of the electriL hoist is clarified.forces are discussed. The effects of the torsional stiffness and rotating speed of the

38

main shaft, and the emergency brake torque on the transient contexts are summarized. Major damage patterns from past

torque produced in the main shaft are discussed. Dynamic U.S. earthquakes are identified, as well as factors such as

load factors for the wire rope are also discussed. configuration, use, location, and construction technologywhich might affect the seismic performance of differentsubcategories of unreinforced masonry buildings.

STRUCTURAL SYSTEMS83-2151Cladding-Structure Interaction in Highrise Buildings

B.J, Goodno, J.I. Craig, M. Meyyappa, and H. PalssonBRIDGES Georgia Inst. of Tech., Atlanta, GA, Rept. No. NSF/

CEE-83003, 618 pp (Jan 1983)PB83-195891

83-2149Methodology for the Dynamic Analysis of Bridge/ Key Words: Buildings, Multistory buildings, Cladding effect,

Abutment/Backfill Systems Subjected to Traveling Seismic responseSeismic WavesB.D Dendrou The potential lateral stiffness contribution of heavy-weightAgbabian Associates, E! Segundo, CA, Rept. No. claddings on buildings and the role of cladding in altering

dynamic properties and linear seismic response were investi-AA-R-8113-5470, 254 pp (Mar 1983) gated.P883-189357

Key Words: Bridges, Seismic excitation, Seismic waves,Moving loads

83-2152This report describes an advanced methodology (BASSIN), Damage Analyses of Imperial County Services Build-for analyzing traveling seismic wave effects on the dynamic ingresponse of an arbitrarily-configured, elastic bridge system.A substructuring approach has been used to formulate R. Shepherd and A.W. Plunkett

BASSIN; the bridge system is represented using a three. Univ. of California, Irvine, CA 92717, ASCE J. Struc.dimensional finite element model, and the underlying soil is Engrg., 109 (7), pp 1711-1726 (Juy 1983) 15 figs,depicted using a boundary element approach based on 6 refselastic half-space theory.

Key Words: Buildings, Reinforced concrete, Concretes,Earthquake damage

BUILDINGS The failure of the Imperial County Ser ',-es Building in ElCentro, California, during the Imperia Valley Earthquake~on October 15, 1979, is examined. The event was excep.

tional insofar as a modern reinforced concrete building,

83-2150 designed to comply with a recent code, extensively instru-

Alternative Methods for Hazard Reduction in Unrein- mented and previously subjected to dynamic testing, was

forced Masonry Buildings severely damaged. Available records of measured dynamic

M. Durkin characteristics and traces of the motions induced by theearthquake in both the adjacent ground and the structure,

Woodland Hills, CA, Rept. No. NSF/CEE-82098, 46 enable critical an alyses to be made of the failure modes.pp (Dec 1982)PB83-186858

Key Words: Buildings, Masonry, Earthquake damage FOUNDATIONS

This report concerns the development of alternative hazardreduction strategies for unreinforced masonry buildings. The 83-2153major characteristics and evolutionary trends of different Dynamic Stiffness of Two Layers in Contact Sub-types of unreinforced masonry buildings in different urban jected to Torsional Oscillations

39

1- 4f

H.H. Jabali Ph.D. Thesis, Univ. of California, Berkeley, 202 ppPh.D. Thesis, Univ. of Miami, 57 pp (1982) (1982)DA8313094 DA8312876

Key Words: Foundations, Layered materials, Seismic analy- Key Words: Dams, Seismic response, Interaction: structure-sis, Torsional excitation, Interaction: soil-structure fluid

Of important practical interest to engineers involved in Two topics are studied with regard to the analysis of non-seismic analysis is the response of a structure on a layered linear dynamic response of arch dams to earthquakes. Part Ifoundation. For such a study, the dynamic stiffness of the deals with the dam-reservoir effects considering incompres-foundation must be investigated. The forced torsional vibra- sible fluid. The hydrodynamic effect represented by added-tion of an elastic stratum consisting of two layers in contact mass matrix is evaluated by two basically different proce-and of dissimilar material is considered. dures - a generalized Westergaard formula and the Galerkin

finite element method. Part II deals with the contractionjoint opening behavior. An economical model called theInterface Smeared Crack Model is developed to simulatethe joint opening nonlinear mechanism.

HARBORS AND DAMS

83-2154Nonstationary Random Vibrations of an Elastic POWER PLANTSGravity Dam with an Arbitrary Shaped Cylindrical (See Nos. 2203, 2277)Reservoir (Instationlire Zufallsschwingungen einer

elastischen Gewichtsmauer bei beliebig geformtemBecken)F. Hollinger and F. Zieglerlechnische Univ. Wien, Vienna, Austria, Z. angew.Math. Mech., 63(1), pp 49-54 (1983) 3 figs, 17 refs(In German) OFF-SHORE STRUCTURES

Key Words: Dams, Seismic response, Earthquake response,Random excitation

A solution for earthquake excited vibrations of a linearelastic gravity dam in plane strain) including hydrodynamic 83-2156interaction with the two-dimensional, linear compressible, Dynamic Ice-Structure Interaction During Continu-inviscid fluid body in an arbitrary shaped cylindrical reservoiris presented. The plane hydrodynamic problem is solved by oUs Crushing

means of a boundary integral equation method. The plane M. Maattanenvibrations induced by nonstationary random excitation Cold Regions Res. and Engrg. Lab., Hanover, NH,processes are given by time variant power spectral densities. Rept. No. CRREL-83-5, 56 pp (Feb 1983)

A D-A 126 349

Key Words: Interaction: ice-structure, Off-shore structures,Model testing, Experimental test data

83-2155 This report presents the results of dynamic ice-structureOn the Nonlinear Dynamic Response of Arch Dams interaction model tests conducted at the CRREL Ice Engi-to Earthquakes - 1. Fluid-Structure Interaction: neering Facility. A flexible, single-pile, bottom-founded

offshore structure was simulated by a test pile with aboutAdded-Mas Computations for Incompressible Fluid one-to-ten scale ratio. Six ice fields were frozen and 1811. Joint Opening Nonlinear Mechanism: Interface tests carried out. In all cases distinctive dynamic ice struc-Smeared Crack Model ture interaction vibrations appeared, from which 6-undantJS-H. Kuo data were collected.

40

ILL

VEHICLE SYSTEMS AIRCRAFT(Also see Nos. 2246, 2278, 2351)

83-2159Enhanced Manual Controllability Via Active Control

GROUND VEHICLES of Aeroelastic Vehicles(Also see Nos. 2177, 2182, 2346) D K. Schmidt

School of Aeronautics and Astronautics, Purdue

Univ, Lafayette, IN, Rept No. NASA-CR-170118,83-2157 58 pp (1983)Suspension Bounce Response of Canadian MAGLEV N83-20952Vehicle under Guideway Excitations. Part 1: Deter-ministic Analysis Key Words: Aircraft, Elasticity theory, Modal analysis,M. Kotb, T.S. Sankar, and M Samaha Active control

Dept of Mech. Engrg., Concordia Univ., Montreal,Quebec, Canada, J Vib. Acoust Stress Rel. Des., A modal analysis technique was developed for evaluating theTrans ASME, 105 (1). pp 104-111 (Jan 1983) 9 effects of elastic modes on aircraft dynamic response, and the

figs, 9 refs handling qualities implication of these effects.

Key Words: Ground effect machines, Magnetic vehicle sus-pensions, Periodic excitation, Guideways, Time domainmethod, Frequency domain method

The dynamic bounce response of the Canadian designed high 83-2160speed magnetically levitated vehicle is investigated when Real-Time Flutter Analysis of an Active Flutter-subjected to purely periodic excitations from the guideways. Suppression System on a Remotely Piloted ResearchThe equations of motion of the system are derived, on the Aircraftbasis of a realistic linear mathematical model, using d'Alem- G.B. Gilyard and J.W. Edwardsbert's principle of force and moment analysis. Solutions for Hugh L. Dryden Flight Res. Ctr., NASA, Edwards,the system responses in the time and frequency domain areobtained using numerical techniques. CA, Rept. No. NASA-TM-84901, 18 pp (Jan 1983)

N83-18710

Key Words: Aircraft, Flutter, Active-flutter control, Realtime spectrum analyzers

83-2158Results of Analysis of 70 Ton Boxcar Vibration Tests Flight flutter-test results of the first aeroelastic research wing

of NASA's drones for aerodynamic and structural testingG. Kachadourian program are presented. The flight-test operation and theMITRE Corporation, McLean, VA, Rept. No. MTR- implementation of the active flutter-suppression system are82W00104, DOT/FRA/ORD-83/06, 68 pp (Mar described as well as the software techniques used to obtain

1983) real-time damping estimates and the actual flutter testingPB83-197723 procedure.

Key Words: Freight cars, Box cars, Vibration tests

This is the second of three volumes covering tests performedon a 70 ton boxcar with Barber S-2-C trucks. The objectiveof the testing was to define the dynamic properties of the 83-2161freight car for use in validating a mathematical model. The Flight Equation of Motion: Computer Analysis.testing was conducted in two phases: static tests were per- 1972 -April 1983 (Citations from the Internationalformed on each truck to characterize its stiffness and damp- Aerospace Abstracts Data Bae)ing properties; vibration tests were performed on the com-

plete boxcar, loaded and empty, to determine resonant fre. NTIS, Springfield, VA, 254 pp (Apr 1983)

quencies, PB83-863100

41

J& A.-.. -

Key Words: Aircraft, Spacecraft, Flutter, Dynamic structural properties. A five mode Rayleigh-Ritz formulation is usedanalysis, Computer programs, Bibliographies to calculate the equation of motion.

This bibliography contains 251 citations concerning mathe-matical procedures explaining the nature of objects in mo-

tion. The topics present a variety of examples and experi-

ments and include spin performance of aircraft, airframe flut- 83-2164ter and dynamic structural analysis, aircraft perTormance.accident analysis, flight simulation, missile and weapons data, Transonic Pressure Distributions on a Rectangularand spacecraft performance. The solutions presented empha- Supercritical Wing Oscillating in Pitchsize computer optimizations and techniques documenting R.H. Ricketts, M.C. Sandford, D.A. Seidel, and J.Jboth analog and digital modeling. Watson

NASA Langley Res. Ctr., Hampton, VA, NASA-TM-84616, AIAA-PAPER-83-0923, 12 pp (Mar1983) (Presented at 24th AIAA/ASME/ASCE/AHSStruct., Struct. Dyn. and Mater. Conf., Lake Tahoe,

83-2162 NV, May 2-4, 1983)Analysis of Unswept and Swept Wing Chordwise N83-20914Pressure Data from an Oscillating NACA 0012 Air-foil Experiment. Volume 1. Technical Report Key Words: Aircraft wings, Airfoils, Aerodynamic loads,

A.D. St. Hilaire and F.O. Carta Experimental test data

United Technologies Res. Ctr., East Hartford, CT,Rept. No. NASA-CR-3567, 101 pp (Mar 1983) Steady and unsteady aerodynamic data were measured on a

AD-A 126 797 rectangular wing with a 12 percent thick supercritical airfoil.The wing was oscillated in pitch to generate the unsteadyaerodynamic data. The purpose of the wind-tunnel test was

Key Words: Aircraft wings, Airfoils, Aerodynamic stability to measure data for use in the development and assessment of

transonic analytical codes. The effects on the wing pressureThe objective of this investigation was to study the unsteady distributions of Mach number, mean angle of attack, and

chordwise force response on the airfoil surface and to exam- oscillation frequency and amplitude were measured.

ine its sensitivity to the various system parameters. The mainbody of this data analysis was carried out by analyzing thepropagation speed of pressure disturbances along the chord

and by studying the behavior of the unsteady part of the

chordwise pressure distribution at various points of the airfoil

pitching cycle. 83-2165Computer Simulation of an Aircraft Seat and Occu-pant in a Crash Environment. Volume I. Program

SOM-LA (Seat/Occupant Model - Light Aircraft)User Manual

83-2163 D.H. Laananen, J.W. Coltman, and AD. Bolukbasi

Aeroelastic Properties of Straight and Forward Swept Simula, Inc., Tempe, AZ, Rept. No. TR-81415,

Graphite/Epoxy Wings DOT/FAA/CT-82/33-2, 234 pp (Mar 1983)

B J. Landsberger AD-A127 286

Air Force Inst. of Tech., Wright-Patterson AFB, OH,

Rept. No AFIT/CI/NR-83-1 1T, 159 pp (Feb 1983) Key Words: Crash research (aircraft), Crashworthiness, Air-

A D-A 127 01 4 craft seats, Human response, Safety restraint systems, Com-

puter programs a

Key Words: Aircraft wings, Cantilever plates, Aeroelasticity, A mathematical model of an aircraft seat, occupant, andNatural frequencies, Flutter restraint system has been developed for use in analysis of

light aircraft crashworthiness. Because of the significantThe aeroelastic deformation, divergence and flutter behavior role played by the seat in overall system crashworthiness, a Jof rectangular, graphite/epoxy, cantilevered plate type wings finite element model of the seat structure is included. Thisat zero sweep and thirty degrees of forward sweep is investi- volume of the final report presents instructions for preparinggated for incompressible flow. Since the wings have varying input data and operating the program, supported by de-amounts of bending stiffness, torsion stiffness and bending- tailed example. Sample material properties and modelingtorsion stiffness coupling, they each have unique aeroelastic parameters are also included,

42

=I ml mm I

83-2166 tests, noise data from 12 microphones was recorded on

YAH-63 Helicopter Crashworthiness Simulation and magnetic tape for subsequent data reduction, The rotor

Analysis system was operated at 4 tip speeds. Following completion

of the rotor and subsystem noise measurements, soundV.L. Berry, J.D. Cronkhite, T.J. Haas, and G.S. Perry field calibration measurements were made of both the

Bell Helicopter Textron, Fort Worth, TX, Rept. No. rotor bowl and the loudspeaker system used in the bowl

USAAVRADCOM-TR-82-D-34, 259 pp (Feb 1983) calibration measurements.AD-A125 642

Key Words: Helicopters, Crashworthiness, Experimental test

data

Under its ongoing crash research testing program, the Army 83-2169conducted drop test T-41 using a YAH-63 prototype heli- Design of Helicopter Rotor Blades for Optimumcopter as a test article. The YAH-63 was residual hardware Dynamic Characteristicsfrom the AAH competition of the mid 70's and incorporated D.A. Peters, T. Ko, A.E. Korn, and M.P. Rossowmany crashworthy features, including a high energy landing

gear, crushable fuselage structure, stroking crew seats, high Dept. of Mech. Engrg., Washington Univ., St. Louis,

strength retention of large masses, and a crash-resistant fuel MO, Rept. No. NASA-CR-169940, 81 pp (Feb

system. 1983)N83-18716

Key Words: Helicopters, Propeller blades, Optimum design

83"2167 The possibilities and limitations of tailoring blade massCalculation of the Longitudinal Stability Derivatives and stiffness distributions to give an optimum blade design

and Modes of Motion for Helicopter Aircraft in terms of weight, inertia, and dynamic characteristics are

H.J. O'Neil discussed. The extent that changes in mass of stiffness distri-

M.S. Thesis, Naval Postgraduate School, Monterey, bution can be used to place rotor frequencies at desiredCA, 114 pp (Oct 1982) locations is determined. Theoretical limits to the amount of

frequency shift are established. Realistic constraints on blade

AD-A 125 593 properties based on weight, mass, moment of inertia, size,

strength, and stability are formulated. The extent that

Key Words: Helicopters, Dynamic stability the hub loads can be minimized by 1roper choice of Eldistribution, and the minimum hub loads which can be

An analysis of the longitudinal stability derivatives for hell- approximated by a design for a given set of natural frequen-

copter aircraft is presented and intended to be used as a cies are determined. Aerodynamic couplings that mightresource document for a helicopter stability and control affect the optimum blade design, and the relative effective-course. Emphasis is given to the evolution of forces and ness of mass and stiffness distribution on the optimization

moments on the helicopter, calculation of the stability procedure are investigated.

derivatives at high advance ratios, derivation of the stabilitydeterminant and solution of the characteristic equation toyield the modes of motion of the helicopter.

MISSILES AND SPACECRAFT(Also see No. 2161)

83-2168I X.Wing Noise DataAcquisition Program

G.J. Healy 83-2170Lockheed Aircraft Corp., Burbank, CA, Rept. No. Dynamics of a Deploying Orbiting Beam-TypeNASA-CR-166454, 90 pp (Feb 1983) Appendage Undergoing VibrationsN83-18717 K.W. Lips and V.J. Modi

Dept. of Mech. Engrg., The Univ. of British Colum-Key Words: Helicopters, Propeller blades, Noise measurement bia, Vancouver, B.C. Canada V6T IW5, J. Vib.

Acoust. Stress Rel. Des., Trans. ASME, 105 (1), pp <6The X-wing circulation controlled rotor system model wasS

tested for hover performance. During these performance 33-39 (Jan 1983) 7 figs, 11 refs

_ ,,43

Key Words: Spacecraft antennas, Vibration analysis Acustica, 52 (5), pp 279-280, 281-289 (Apr 1983)9 figs, 3 tables, 28 refs

Vibration characteristics associated with a deploying space- (In German)craft appendage in an arbitrary orbit are investigated numer-ically. A general formulation of the problem is presentedwhich accounts for the shifting center of mass, appendage Key Words: Industrial facilities, Noise generation, Humanoffset, arbitrary variation of flexural rigidity along the responseappendage length, deployment acceleration, satellite libra-tions, etc. Twenty-five representative industrial noises are presented

to 80 subjects for the evaluation of annoyance by pair-comparison. The evaluation of the subjective estimation ismade by the process of the principle components analysisRelevant acoustic parameters, whose measuring methods arepresented and discussed, are taken for correlation with these

83-2171 results.

Equivalent Angle-of-Attack Method for EstimatingNonlinear Aerodynamics of Missile FinsM.J. Hemsch and JN. NielsenNielsen Engrg. & Res., Inc., Mountain View, CA, MECHANICAL COMPONENTSJ. Spacecraft Rockets, 20 (4), pp 356-362 (July/Aug 1983) 9 figs, 1 table, 19 refs

Key Words: Missile components, Aerodynamic stabilityABSORBERS AND ISOLATORS

A method has been developed for estimating the nonlinear (Also see ANs. 2181 2264, 2283)

aerodynamic characteristics of missile wing and control (

surfaces. The method is based on the assumption that if afin on a body has the same normal-force coefficient as awing alone composed of two of the same fins joined together 83-2173at their root chords, then the other force and momentcoefficients of the fin and the wing alone are the same, Optimal Des of Linear and Nonlinear Vibrationincluding the nonlinearities. The method can be used for Absorbers for Damped Systemsdeflected fins at arbitrary bank angles and at high angles of A. Soom and M.-S. Leeattack. A full derivation of the method is given, its accuracy Dept. of Mech. and Aerospace Engrg., State Univ. ofis demonstrated, and its use in extending missile data bases New York at Buffalo, Amherst, NY 14260, J. Vib.is shown. I

Acoust. Stress Rel. Des., Trans. ASME, 105 (1), pp112-119 (Jan 1983) 18 figs, 11 refs

Key Words: Dynamic vibration absorption (equipment),

S ' BIOLOGICAL SYSTEMS Tuning, Damping, Optimum design

Nonlinear programming techniques are applied to obtain4i optimal tuning and damping parameters for dynamic ab-

sorbers. The optimization is carried out for damped as wellas undamped primary systems. It is found that optimal

HUMAN tuning parameters, obtained with the goal of minimizing themain mass maximum displacement, undergo small changesas damping is introduced into the main system.

83.2172Physic Parameters in the Evaluation of the Annoy-

ance of Industrial Noises (Physikalische Parameterbei der Bewertung der L'stigkeit von Industrieger- 83-2174"uschen) Method of Actuator Placement for Vibration Control 4W Brennecke and H. Remmers of Large Space Structures 4Fachbereich Physik an der Universiiat Oldenburg, R.E. Ort

44

. ... m mIu

Air Force Inst. of Tech., Wright-Patterson AFB, OH, Key Words: Suspension systems (vehicles), MathematicalRept. No. AFIT/CI/NR-83-1-T, 90 pp (Feb 1983) models, Human response

AD-A 126 940An approach for the design of a new car suspension using anonlinear mathematical model is described. A brief descrip-

Key Words: Vibration control. Active vibration control tion of the linear de Carbon model and its properties isrecalled; effects and importance of some nonlinear param-

This thesis presents several computationally simple tech- eters are discussed; a model including these parameters isniques for choosing actuator placement on large space struc- introduced and it is shown that this nonlinear model stilltures. Actuator and performance information can be repre- approximately verifies one property of the de Carbon model.sented as vectors (node shapes) in modal coordinates. The Using this important characteristic, a procedure for theplacement problem is stated as choosing a set of actuator design of a new suspension using a nonlinear model is pre.node shapes to match the performance node shape. One sented,method sequentially selects a set of actuator node shapessuch that the norm of the component orthogonal to thealready selected set is large. Another method sequentiallyselects actuator node shapes such that a large projection isobtained along the least squares residual vector resultingfrom the fit of the previously selected set to the perfor- 83-2177mance node shape. These techniques are applied to a 100 Computer-Aided Analysis and Experimental Verifi-meter cantilever beam. cation of a Motorcycle Suspension

M. van Vliet and S. Sankar

Concordia Univ., Montreal, Quebec, Canada H3G1M8, J. Vib. Acoust. Stress Rel. Des., Trans. ASME,

83-2175 105 (1), pp 120-131 (Jan 1983) 20 figs, 3 tables,

Fail-Safe Vibration Control Using Active Force 17 refs

GeneratorsR.R Guntur and S. Sankar Key Words: Suspension systems (vehicles), Motorcycles,

Dept. of Mech. Engrg., Concordia Univ., Montreal, Computer-aided techniques

Quebec, Canada, J. Vib. Acoust. Stress Rel. Des., A computer-aided analysis and experimental verification of aTrans. ASME, 105 (3), pp 361-368 (July 1983) motorcycle suspension are presented. A mathematical model15 figs, 1 table, 11 refs describing the flow characteristics in a front fork and a rear

shock absorber was independently developed for both com-pression and extension strokes. The model includes both

Key Words: Active vibration control, Suspension systems laminar and turbulent flow conditions and the spring effect(vehicles) due to entrapped air in front fork and gas charged chamber

Using the concept of force generators, various active vibra- in the case of rear shock absorber. A sinusoidal displace-

tion configurations have been examined for their perfor- ment was considered as the input excitation for the model.

mance potential. It is shown that an active vibration controlsystem offers a great deal of flexibility in that by a properchoice of active components its transmissibility characteris-tics can be altered to suit the requirements. It is also shownhow the full potential of active systems can be achieved 83-2178even when there are passive components. Determination of Dynamic Properties of Elastomers

over Broad Frequency RangeG.M. Smith, R.L. Bierman, and S.J. ZitekUniv. of Nebraska, Lincoln, NE 6588-0347, Exptl.

83,2176 Mech., 23 (2), pp 158-163 (June 1983) 10 figs,

Study of Ride Comfort Using a Nonlinear Mathe- 6 ref s

matical Model of a Vehicle SuspensionA. Jolly Key Words: Elastomers, Dynamic tests, Dynamic properties,

Direction des Recherches et des Developpements de High frequencies

la Regie Nationale des Usines Renault, Rueil-Mal- Support excitation of a small spring-mass system, consistingmaison, France, Intl. J. Vehicle Des., 4_(3), pp 233- of a mass m and two thin wafers in shear. Is used as a simple244 (May 1983) 11 figs, 7 refs and reliable method to determine the dynamic properties

45 I,--.4 ' i

(storage-modulus and complex-modulus loss factor) of Vehicle Des., 4 (3), pp 312-322 (May 1983) 4 figs,elastomeric materials over a fairly broad frequency range. 2 tables, 2 refsNo special equipment or instrumentation is required since

ordinary vibration equipment is used. Microminiature accel-erometers are used to monitor the support and mass accelera- Key Words: Springs. Leaf springs, Energy absorptiontions which eliminates the measurement of small forces and

displacements. Composite leaf springs constructed of unidirectional glass

fibers in an epoxy resin matrix are being recognized as a

viable replacement for steel springs in truck and automotive

suspension applications. This paper reviews the function of a

spring as an energy storage device. It examines in detail the

influence on that function of the material of construction(unidirectional glass fibers in epoxy versus steel) and of

83-2179 spring geometry. The design latitudes afforded by the vari-Energy Absorption of Composite Materials able thickness/width options are illustrated. Finally, the

significance of shear stress components in planes containing

G L Farley the fibers is examined, particularly in its relation to the

NASA Langley Res. Ctr., Hampton, VA, Rept. No. selection of the thermoset resin matrix.

NASA-TM-84638, 9 pp (Mar 1983) (Presented atNatl Specialists' Meeting: Composite Structures,

Mar 1983; Sponsored by American Helicopter Soc.)N83-19816 TIRES AND WHEELS

Key Words: Energy absorption, Composite materials, Com-

pressive strength

Results of a study on the energy absorption characteristics 83-2182of selected composite material systems are presented and the Eulerian Dynamics of a Biconeresults compared with aluminum. M. Dec yper

Universite Catholique de Louvain, Louvain-la-Neuve,Belgium, Intl. J. Vehicle Des., 4 (4), pp 413-429(July 1983) 4 figs, 2 tables, 4 refs

Key Words: Wheelsets, Railway wheels, Conical bodies,

83-2180 Euler equation, Equation. of motion, Railroad cars

Review of Data on Rubber MountingsChartered Mech. Engr., 30 (6), pP 28-31 (June 1983) The purpose of this paper is to resume the problem of

13 figs, 9 refs wheelset dynamics at a fundamental level by deriving theEulerian equations of motion of an idealized model of

wheelset on an idealized track. The translation and rotationKey Words: Mountings, Elastomers, Energy absorption equations are derived for a bicone (pair of conical wheels)

of any conicity on a straight sharp-edged track. The kine-The material properties required for various applications of rnatical constraints are deduced from nonlinear analyticalrubb mountings are presented. principles which are then linearized.

SPRINGS 83-2183

On the Lateral Stability of a Flexible TruckA.M. WhitmanTel-Aviv Univ., Tel-Aviv, Israel, J. Dynam. Syst.,

83.2181 Meas. Control, Trans. ASME, 105 (5), pp 120-125Glass Fibre Reinforced Epoxy Leaf Spring Design (June 1983) 7 figs, 7 refsWG. Gottenberg and K H Lo

Shell Development Co., Westhollow Research Ctr., Key Words: Wheelsets, Railway wheels, Railroad cars, Sta-

3333 Highway 6 South, Houston, TX 77001, Intl. J. bility, Lateral response

46

V '

Analytic formulae for the critical speed and frequency of an W.-Z Wuinterconnected pair of wheelsets based on an asymptotic Ph.D. Thesis, Univ. of California, Berkeley, 112 ppexpansion in a truck geometric parameter are derived. No (1982)restriction is placed on the values of either the shear orbending stiffness; the entire structure of the stability surface DA8313027is obtained. Expressions are obtained for the local and globalextrema and their locations. Key Words: Saws, Blades, Natural frequencies, Mode shapes,

Flexural vibration, Torsional vibration

The variation of natural frequencies and mode shapes of a

BLADES cutting blade from dynamic vibration to static buckling are(Also see No. 2224) studied. Bending-torsional coupled transverse vibrations in

a linear undamped axially moving thin beam model areinvestigated. The study also develops an accurate, compre-

83-2184 hensive, fast and inexpensive analytical method for efficientAn Actuator Disc Analysis of Unsteady Supersonic analyses of the natural frequencies and mode shapes of thecutting blade. Parametric resonances caused by a periodicCascade Flow edge load in the plane of a moving band and normal to theDS. Whitehead and M.R.D. Davies longitudinal axis are also investigated. The relationship, toWhittle Lab., Cambridge Univ. Engrg. Dept., Cam- cause a parametric instability and induce a large amplitudebridge, UK, J. Sound Vib., 88 (2), pp 197-206 (May transverse vibration, among the moving velocity, the tension,

the system compliance coefficient, and the periodic load22, 1983) 4 f igs, 10 refs amplitude as well as variation frequency is established in this

study.Key Words: Blades, Cascades, Disks (shapes), Plates, Fluid-

induced excitation

A simple analytical result is derived for the aerodynamicforces and moments acting on a cascade of unloaded flat BEARINGSplates vibrating in a supersonic flow. The principal assump- (Also see No. 2226)tions are that the axial velocity is subsonic, that the bladesare sufficiently closely spaced so that a Mach wave cannot

propagate upstream through the cascade, and that the fre-quency parameter and inter-blade phase angle are both small.The unique incidence condition is used. 83-2187

Eccentric Operation of Conical Hydrostatic ThrustBearingsJ.J. Prabhu and N, Ganesan

83-2185 Machine Dynamics Lab., Dept. of Applied Mechanics,8318 Bld iIndian Inst. of Tech., Madras 600036, India, Wear,Turhomachine Blade Vibration 87, pp 273-285 (1983) 19 figs, 11 refs

,,! J.S. Rao

Indian Inst. of Tech., New Delhi-110016, India, Key Words: Bearings. EccentricityShock Vib. Dig., 15 (5), pp 3-9 (May 1983) 90 refs

A theoretical study of the behavior of capillary-compen-Key Words: Blades, Turbomachinery blades, Free vibration, sated annular recess conical hydrostatic thrust bearingsReviews under conditions of eccentricity and rotation is reported,

The influence of aspect ratios, cone angles and resistanceThis article reviews the literature that has appeared since ratios on the static and dynamic characteristics is discussed.1979 on free vibrations and excitation forces of blades andblade response.

83-218883-2186 Hydrodynamic Instability of Self-Acting JournalThe Vibration and Stability Analysis of Axially Bearings of Finite Length in the Turbulent RegimeMoving Materials: A Special Study on Band Saw V. KumarSystems Regional Engrg. College, Kurukshetra Haryana,

47I . 4

132119, India, Wear, 88 (2), pp 133-143 (July 1, 83-21911983) 3 figs, 11 refs Analysis of Misaligned Journal Bearings with Axial

and Spiral FeedingKey Words: Bearings, Journal bearings, Dynamic stability M.O.A. Mokhtar, M.A. Abdel Rahman, and Z.S. Safar

Mechanical Design Dept., Cairo Univ., Cairo, Egypt,An analysis for the determination of the conditions of Wear, 85 (3), pp 331-337 (Mar 15, 1983) 7 figs,dynamic stability of hydrodynamically lubricated plain 4 ref scircular bearings of finite length with turbulent flow is pre-sented. The conditions for both static and dynamic stabilityare calculated from the response to a small random distur- Key Words: Bearings, Journal bearings, Alignmentbance. The dynamic stability is investigated with the Routh-Hurwitz criterion using the perturbation (or linearization) An analysis of misaligned journal bearings with both axialtechnique. The results are fully analytical and are in the and spiral feeding is presented. The misalignment varies inclosed form. magnitude and in direction with respect to the bearing

boundaries. Results for a stationary journal centre andL/D = 1 demonstrate that misalignment in line with theaxial plane containing the load vector is more advantageousand that bearings with axial feeding produce higher loadsand smaller values of the coefficient of friction than bearings

83-2189 with spiral feeding.

Roling Bearing Noise - Cause and CureF.P, Wardle and S.Y. PoonRHP Bearing Res, Ctr., Chartered Mech. Engr., 30

(7/8), pp 36-40 (Aug 1983) 14 figs, 3 refs 83-2192

Key Words: Bearings, Rolling contact bearings, Noise genera- Design of an Offset Hydrostatic Thrust Bearusg undertion. Noise reduction Dynamic Loading Conditions

Z.S. SafarRolling bearings are quiet running components and only Dept. of Mech. Engrg., Cairo Univ., Cairo, Egypt,become noticeable as sources of noise in a iimited range of Wear, 84 (1), pp 87-96 (Jan 1, 1983) 9 figs, 9 refsmachines. These machines usually share a number of com-mon features: they are used in quiet environments, have few

other sources of noise and run at speeds of more than 1000 Key Words: Bearings, Thrust bearings, Saws, Vibration

rev/m in. effects

An offset hydrostatic thrust bearing is analyzed to deter-mine the effect of vibration of the rotating plate on perfor-mance characteristics. The flow developed is asymmetricbecause the surface rotation axis is offset from the bearing

83-2190 axis. The governing Reynolds equation is solved using semi-

Some Dynamic Effects in High-Speed Solid-Lubri- analytical methods. The average load capacity, frictionalcated Ball Bearings force and lubricant flow rate are strong functions of theP Gbearing offset L, bearing number X, film thickness profileSP.K. Gupta H, film thickness variation E and the ratio between the

Mechanical Technology Inc., Latham, NY 12110, frequency of vibration of the rotating plate and the angular

ASLE, Trans., 26 (3), pp 393-400 (July 1983) 8 figs, speed of rotation.1 table, 14 refs

f i Key Words: Bearings, Ball bearings, Computer programs GEARS

Dynamic performance simulations of a high-load, high-speedball bearing for turbine-engine applications are consideredusing the available dynamics of rolling element bearings 83-2193computer program. It is shown that the key element in the Calculation of Tooth Forces, Pressures and Stressesbearing design is the traction behavior at the ballrace inter- in Spur and Bevel Gears (Berechnung der Zahnkiafte,face for the prescribed materials. With a given traction model,the geometry of the bearing may be designed to ensure Pressungen und Spannungen Yon Stim- und Kegel.

acceptable bell/cage collision forces and to ensure the general radgetrieben)stability of the cage. B. Neupert

48

Ii _ _

Fortschritt-Berichte VDI-Zt., Reihe 1, No. 104 Cleveland State Univ., OH, 17 pp (Jan 1983) from:(1983), 162 pp, 85 figs. Summarized in VDI-Z, Advanced Power Transmission Technology, Proc. of125 (10), pp 360-361 (May 1983). Avail: VDI-Ber- Symp. held at NASA Lewis Res. Ctr., Cleveland,lag GmbH, Postfach 1139, 4000 Dusseldorf 1, Ger- OH, June 9-11, 1981many. Price 54.00 DM AD-A126 186(In German) AD-P000 722

Key Words: Gears, Spur gears, Bevel gears, Gear teeth, Corn- Key Words: Gears, Spur gears, High-contact ratio gearsputer programs

Many advanced technology applications have a general re-A general form algorithm is presented which is particularly quirement that the power to transmission weight be in-suitable for the calculation of complex relationships between creased. The ability to accurately calculate the dynamictooth forces, deformation, and stresses in helical gears during loads becomes essential for advanced transmission design.engagement. The calculations are in the form of consecutive- This paper discusses the mesh stiffness and dynamic loadly run digital computer programs with 30,000 Fortran corn- characteristics for several cases of normal contact ratio endmands. Because of its general form the method can be used high contact ratio gearing.for other types of gears, as well as for failure analysis ofgears In addition, the algorithms developed can also beused in other contact problems, such as for the determina-tion of load distribution in rolling element bearings, and inguidance systems for machine tools as well as for the opti-mum sizing of ball bearings. 83.2196

Computer Solution for the Dynamic Load, LubricantFilm Thickness, and Surface Temperatures in Spiral-Bevel Gears

83-2194 H.C. Chao, M. Baxter, and H.S. ChengDynamic Tooth Loads and Stressing for High Contact Garrett Turbine Engine Co., Phoenix, AZ, 19 ppRatio Spur Gears (Jan 1983) from: Advanced Power TransmissionR.W. Cornell and W.W. Westervelt Technology, Proc. of Symp. held at NASA LewisHamilton Standard Div., United Technologies Corp., Res. Ctr., Cleveland, OH, June 9-11Windsor Locks, CT, 12 pp (Jan 1983) from Advanced AD-A126 186Power Transmission Technology, Proc. of Symp. AD-POO 719held at NASA Lewis Res. Ctr., Cleveland, OH, June 9-11, 1981 Key Words: Gears, Bevel gears, Computer programsAD-A126 186AD-POO0 727 A computer solution to the dynamic load in a pair of spiral-

bevel gearsets was developed by solving the equations ofmotion for the pinion and gear shaft. An existing finite-

Key Words: Gears, Spur gears, Gear teeth, Computer pro- element code was used to calculate the combined stiffnessgrams of the contacting pinion and gear teeth as a function of

contacting position in the zone of action. In addition to theAn analysis and computer program has been developed for dynamic load analysis, a computer solution was also devel-calculating the dynamic gear tooth loading and root stressing oped to predict the bulk surface temperature, the flashfor HCRG as well as LCRG. The analysis includes the effectsof the variable tooth stiffness during the mesh, tooth-profilemodification, and gear errors. The calculation of the toothroot stressing causpi by the dynamic gear loads Is based on amodified Heywood gear tooth stress analysis, which appearsmore univmselly applicable to both LCRG and HCRG. FASTENERS

83-2195 83-2197 /1Method for Static and Dynasnic Load Andysi of Seianic Moment Connections for Moment-ResistingStandard and Modified Spur Gears Steel FramesR. Kasuba E.P. Popov

49

. . . .-

.4-]

Earthquake Engrg. Res. Ctr., Univ. of California, Key Words: Joints (junctions), Beams, Columns, SeismicBerkeley, CA, Rept. No. UCB/EERC-83/02, NSF/ response

CEE-83009, 65 pp (Jan 1983) Six full-sized interior beam-to-column subassemblages werePB83-195412 tested under quasi-static loading which was intended to

simulate earthquake input. Three variables were investigated:Key Words: Joints (junctions), Framed structures, Steel, percentage of transverse hoop reinforcement in the joint;Seismic response joint shear stress level; and presence of transverse beams and

slab on half of the specimens.This report provides an overview of the state of the art forthe design of steel moment connections for regions of highseismic risk. The need for designing such connections to beductile with the copacity to sustain full load reversals isindicated. A major section of the report is devoted to presen-tation of experimental results to illustrate the observed be-havior of beam-to-column connections and column panel The Damping of Structural Vibration by Controlledzones under severe cyclic loadings simulating extreme seismic Interfacial Slip in Jointsconditions. C.F. Beards

Dept. of Mech. Engrg., Imperial College of Science

and Technology, London SW7, UK, J. Vib. Acoust.

Stress ReL. Des., Trans. ASME, 105 (3), pp 369-373

83-2198 (July 1983) 4 figs, 41 refs

System Identification of Structures with Joint Ro-

tation Key Words: Joints (junctions). Vibration damping. Beams

J.S. Dimsdale Plates, Framed structures, Structural members

Ph.D. Thesis, Univ. of California, Berkeley, 144 pp The most significant source of damping inherent in a struc-

(1982) ture is that damping which occurs in the structural jointsDA8312798 due to interfacial slip. Particular emphasis should be put on

controlling and increasing the damping which occurs in thesejoints if the dynamic response, stress, and noise of a structure

Key Words: Joints (junctions), Framed structures, Seismic are to be reduced. It is shown that an optimum joint clamp-excitation, System identification techniques ing force exists for maximum energy dissipation due to slip,

and that the resonance frequencies of structures can beThe goal of this research is to investigate the role of joint controlled to some extent by adjusting the clamping and,behavior in the identification of frame models from dynamic hence, the slip, in joints. The application of joint dampingresponse data caused by seismic forcing functions. Including to beam-like structures, piates, and frameworks is considered,joint rotation and deformation in the mathematical modelfor even simple structures significantly affects the distribu-

tion of stiffness, and the accuracy with which response canbe predicted. An optical method has been devised for accu-rately measuring joint rotation of a structure during earth-quake excitation. A number of different mathematicalmodels of these structures are evaluated using system identifi- 83-2201cation. Behavior of External Reinforced Concrete Beam to

Column Connections Subjected to Earthquake TypeLoadingM.R. Ehsani and J.K. Wight

83-2199 Dept. of Civil Engrg., Univ. of Michigan, Ann Arbor,

Experiaental and Analytical Study of Internal Beam MI, Rept. No. UMEE-82R5, NSF/82099, 267 pp

to Column Connections Subjected to Reversed Cyclic (July 1982)

Loading PB83-188342

A.J. Durrani and J.K. WightDept. of Civil Engrg., Univ. of Michigan, Ann Arbor, Key Words: Joints (junctions), Beams, Reinforced concrete,

MI, Rept. No. UMEE-82R3, NSFICEE-82097,298 pp Columns. Seismic excitation, Earthquakes, Dynamic tests

(July 1982) Twelve full-size exterior beam-to-column sbassembliesPB83-188359 were constructed and tested. The primary variables studied

So

were: ratio of the sum of the flexural strengths of the col- SEALSumns to that of the beam; amount of transverse reinforce-ment placed within the joint; shear stress in the joint; andin-lusion of transverse beams and slab for half of the speci-mens. 832204

Dyna c Analysis of a Hydrodynamic Seal with

Helical Grooves

S.K. Dhagat, R. Sinhasan, and D.V. SinghMech. Engrg. Dept., Govt. Engrg. College, Jabalpur

482011, India, Wear, 87 (2), pp 133-139 (May 16,83.2202 1983) 9 figs, 8 refs

The Fatigue of Weldments Subjected to ComplexLoadings Key Words: Seals, Stiffness coefficients, Damping coeffi-New-Jin Ho cientsPh.D. Thesis, Univ. of Illinois at Urbana-Champaign,151 pp (1982) A ring-type hydrodynamic seal with two lands, one with

DA8309957 helical grooves and the other with a wedge, separated by acircumferential oil supply groove was studied. The dynamicperformance characteristics in terms of the stiffness and

Key Words: Joints (junctions), Welded joints. Fatigue life damping coefficienits, critical mass end critical inertia wereobtained for lateral and skew motions. For the general mo-

Cruciform and double-strap lap weldments were fatigue tion of the seal, stability studies were made by obtaining thetested under constant amplitude axial load end SAE bracket roots of the characteristic equation.spectrum load conditions. The fatigue test results were com-pared with predictions made using an initiation-propagationmodel, and good agreement between experiment and theorywas observed. STRUCTURAL COMPONENTS

VALVESCABLES

(Also see No. 2148)

83-2203

Response of Two Nuclear Power Plant Valves to 83-2205Dynamic Excitation An Analysis of Elevator Rope Vibration in TallS.F. Masri, S.J. Stott, and D.D. Reiff Buildings

Univ. of Southern California, Los Angeles, CA R.E. Blodgett and A.K. Majumdar90007, J. Vib. Acoust. Stress Rel. Des., Trans Merck and Co., Inc., Rahway, NJ, J. Vib. Acoust.ASME, 105 (1), pp 40-50 (Jan 1983) 29 figs, 5 refs Stress Rel. Des., Trans ASME, 105 (1), pp 5-10

(Jan 1983) 8 figs, 2 tables, 1 ref

Key Words: Valves, Nuclear power plants, Nuclear reactorcomponents, Shock excitation Key Words: Cables, Elevators, Multistory buildings. Vibration

damping, Damping

To formulate more suitable testing criteria for safety-related

equipment in nuclear power plants, new investigations of The problem of elevator compensation rope vibration in tallequipment behavior under dynamic loading era required. buildings is addressed. An analysis is made of the vibrationsCurrently usd guidelines and thei applicabitkt are summa ofa hanging rope, whose weight pr unit length is not nel

ized and several major problems to be solved by new Investi- gibla, excited by an oscillation at the upper end and having agations or, described. Experimental and analytical studies weight susMended from the lower end. The effect of intro-conducted on two typical valves exemplify the type of ducing a damper at the upper end in order to limit the vibra-Investigetion required. tion Is also examined.

51

BARS AND RODS Coated Single Field Beams (Einfluaa von Schubedai-tizitift und Drehtfigheit auf die Biegeeigenfrequenzgleichformig massebelegter Einfeldbaiken)

83.2206 R. Cuntze and J. EderA New Higher Order Dynamic Theory for Thermo- Abteilung Strukturauslegung und Berechnung deselastic Bars. I. General Theory M.A.N.-Bereichs Neue Technologie, Miinche, Fed.Y, Mengi and N. Akkas Rep. Germany, Konstruktion, 35 (5), pp 183-186Dept. of Civil Engrg., Cukurova Univ., Adana, Tur- (May 1983) 8 figs, 1 table, 7 refskey, J. Acoust. Soc. Amer., 73 (6), pp 1918-1922 (In German)(June 1983) 1 fig, 8 refs

Key Words: Beams, Layered materials, Timoshenko theory,Key Words: Bars, Approximation methods, Vibration re- Vibration effectssponse, High frequency response

Graphs, based on the differential equations of TimoshenkoA dynamic approximate theory capable of predicting high- beam theory, are presented for the determination of thefrequency behavior of cylindrical thermoelastic bars is effects of shear deformation and rotatory inertia of thedeveloped. The cross section of the bar has an arbitrary shape cross section for five technically significant beam boundaryand contains an arbitrary number of holes. The approximate conditions. The appropriate effect can be determined fromtheory is valid for all of the deformation modes - flexural, their graphs using the curves of normalized correction coeffi-longitudinal, torsional, etc. The use of the new method cient KSD. Theoretical predictions and calculation resultseliminates any inconsistency which may occur between are presented.lateral boundary conditions and the distributions of dis-placements or temperature assumed over the cross sectionof the bar.

83-2209Forced Vibration of Timoshenko Beams Made of

83.2207 Multimodular MaterialsA New Higher Order Dynamic Theory for Thermo- F. Gordaninejad and C.W. Bertelastic Bars. 1l: Application to Thermoelastic Circular School of Aerospace, Mechanical and Nuclear Engrg.,and Rectangular Bars Univ. of Oklahoma, Norman, OK 73109, Rept. No.N. Akkas and Y. Mengi OU-AMNE-83-2, 31 pp (June 1983)Dept. of Civil Engrg., Middle East Technical Univ.,Ankara, Turkey, J. Acoust. Soc. Amer., 73 (6), pp Key Words: Beams, Rectangular beams, Timoshenko theory,

1923-1931 (June 1983) 9 figs, 1 table, 4 refs Transfer matrix method, Forced vibration

This paper presents a transfer-matrix analysis for determiningKey Words: Bars, Approximation methods, Vibration re- the sinusoidal vibration response of thick, rectangular-cross-sponse, High frequency response section beams made of multimodular materials; i.e., mate-

rials which have different elastic behavior in tension and com-To illustrate the power of the theory proposed in Part I pression, with nonlinear stress-strain curves approximatedfor the dynamic behavior of thermoelastic bars, the theory as piecewise linear. A closed-form solution is presented foris applied to bars with circular and rectangular cross sections. the special case in which the neutral-surface location isThe general equations of the approximate theory governing uniform along the length of the beam. Comparisons areall of the deformation modes (longitudinal, flexural, tor- made among multimodular, bimodular (two line segments),

sional, etc.) of circular and rectangular bars, and accommo- and unimodular models. Numerical results for axial displace-dating the thermal effects are presented. ment, transverse deflection, bending slope, bending moment,

Jtransverse shear and axial forces, and the location of theneutral surface are presented for the multimodular model.

BEAMS

83.2208 83-2210The Effect of Shear Deformation and Rotatory Optimal Design of Beams under Flexural VibrationInertia on the Vibration Frequency of Uniformly M.H.S. Elwany and A.D.S. Barr

52

Dept. of Mathematical and Physical Sciences, Alex- vibration of a complex mechanical structure using the natural

andria Univ., Alexandria, Egypt, J. Sound Vib., 8 modes of the components. The natural modes of all compo-(2), pp 175-195 (Ma 22, 1983) 9 figs, 10 tables, 8 nents are synthesized to form the generalized system coordi-

refs nates.

Key Words: Beams, Cantilever beams, Flexural vibration,Minimum weight design

The minimum weight design of a cantilever beam in flexuralvibration is considered. The aim is the maximation of a given 83-2213natural bending frequency (usually the first) for a given beam Instality Mechanims and Stability Criteria of aweight or equivalently the minimization of beam weight fora specified value of a natural frequency. Group of Circular Cylinders Subjected to Cross-

Flow. Part 1: TheoryS.S. ChenArgonne Natl. Lab., Argonne, I L 60439, J, Vib.Acoust. Stress Rel. Des., Trans. ASME, 105 (1), pp

83-2211 51-58 (Jan 1983) 1 fig, 19 refs

Seimsic Reliability of Damaged Concrete BeamsM. Shinozuka and R.Y. Tan Key Words: Cylinders, Tube arrays, Fluid-induced excitation,

Columbia Univ., New York, NY 10027, ASCE J. Heat exchangers

Struc. Engrg., 109 (7), pp 1617-1634 (July 1983) A mathematical model is presented for a group of circular

10 figs, 6 tables, 19 refs cylinders subject to cross-flow. It is found that there aretwo basic dynamic instability mechanisms: instability con-

Key Words: Beams, Earthquake damage. Seismic response. trolled by fluid damping and instability controlled by fluid.

Probability theory elastic force. Approximate closed form solutions of thecritical flow velocity for the two mechanisms are obtained

A method is developed to estimate the reliability of a seis- based on constrained-mode analyses.

mically damaged structure that will be subjected to futureearthquakes. Damage states are defined, and conditional aswell as initial damage probability matrices are introducedin such a manner that the definition of the damage is consis-tent with the kind of accuracy achieved when the extent ofthe structural damage is estimated through field inspections.

83-2214 IFluidelastic Instability of an Infinite Double Row of

Circular Cylinders Subject to a Uniform Cross-Flow

CYLINDERS S.J. Price and M.P. Paidoussis

(Also see Nos. 2226.2229) Dept. of Mech. Engrg., McGill Univ., Montreal, Que-bec, H3A 2K6, Canada, J. Vib. Acoust. Stress Rel.Des., Trans. ASME, 105 (1). pp 59-66 (Jan 1983)

83-2212 6 figs, 21 refs

Analym of Vibration by Component Mode Synthe- Key Words: Cylinders, Tube arrays, Heat exchangers, Fluid--s Method (Part 3. Application to Cylinder Block of Induced excitation4 Cylinders)M. Ookuma and A. Nagamatsu This paper represents the first stage of a fundamental investi-

Doctor Course of Tokyo Inst. of Tech., Bull. JSME, gation of the vibration phenomena induced in heat exchanger26 (215), pp 812-817 (May 1983) 15 figs, 11 refs bundles subject to a cross-flow. Using aerodynamic force2coefficient data, obtained experimentally from a static wind

tunnel model, a linearized quasi-static analysis is employed toKey Words: Cylinders, Component mode synthesis, Vibration analyze the stability of an Infinite double row of circularanalysis cylinders In uniform cross-flow. From the analysis it is U/

shown that the instability Is a result of the negative fluidA cylinder block of 4 cylinders is analyzed by the component damping forces, resulting from the complex flow pattern inmode synthesis method, a general method of analysis of the the row.

5 4

FRAMES AND ARCHES Ph.D. Thesis, Rensselaer Polytechnic Inst., 218 pp(Also see No. 2197) ( 19P1)

DA8311652

83-2215 Key Words: Plates, Orthotropism, Stability, Vibration analy-

Bimodal Optimization of Vibrating Shallow Arches sis

N. Olhoff and R.H. Plaut Transformations to solve the stability and vibrations prob-

Dept. of Solid Mechanics, The Technical Univ. of lems of specially orthotropic plates are proposed. The affine

Denmark, Lyngby, Denmark, Intl. J. Solids Struc., transformations define the similarity rules for these plates,

19 (6), pp 553-570 (1983) 14 figs, 13 refs thereby reducing the numerous parameters (elastic constants)in the orthotropic literature to two. These affinely trans-

formed parameters are the Generalized Poisson's Ratio andKey Words: Arches. Natural frequencies, Optimization the Generalized Rigidity Ratio. With the help of these

A bimodal formulation is developed for the problem of similarity rules, problems of a generic, rather than a specific,

maximizing the fundamental vibration frequency of shallow, specially orthotropic plate can be solved at one time.

elastic arches of given span, volume, length, material, andboundary conditions. Arches with different cross-sectionaltypes are considered, and two simultaneous design variablesare used; namely, the cross-sectional area and arch centerline

functions. Results are also presented for arches with circular 83-2218centerlines. Nonlinear Response Ariing from Non Self-Similar

Crack Growth in Finite Thickness PlatesG.C. Sih and C. ChenInst. of Fracture and Solid Mechanics, Lehigh Univ.,

PLATES Bethlehem, PA, Rept. No. ALO-1016, 45 pp (July(Also see No. 2163) 1982)

D E83005946

83-2216 Key Words: Plates, Crack propagation, Finite element tech-

On the Three Dimensional Analysis of Thick Lami- nique

nated Plates Described in this report is a three-dimensional finite elementKK. Teh, K.C. Brown, and R. Joies procedure for finding the stresses in a finite thickness plate

Univ. of Melbourne, Parkville, Victoria 3052, Austra- with a through crack. The Mode I loading is increased incre-

lia, J. Sound Vib., 88 (2), pp 213-224 (May 22, 1983) mentally such that crack growth occurs in segments.2 figs, 8 tablIes, 26 refs

Key Words: Plates, Layered materials, Finite element tech-nique, Natural frequencies 83-2219

Several finite element models and finite prism models based Free Vibration of Circular-Segment-Shaped Mem-on the elasticity theory formulation are compared. The basis branes and Plates of Rectangular Orthotropyof comparison is the accuracy in predicting natural frequen- T. I rie, G. Yamada, and Y. Kobayashicis of simply supported plates, and the suitability to modeldelamination of composite laminates. The emphasis of this Dept. of Mech. Engrg., Faculty of Engrg., Hokkaido

work is on the finite prism method. Univ., Kita-13, Nishi-8, Kita-ku-Sapporo 060 Japan,J. Acoust. Soc. Amer., 23 (6), pp 2034-2040 (June1983) 9 figs, 1 table, 15 refs

Key Words: Plates, Rectangular plates, Membranes (struc-83.2217 tural members), Harmonic excitation, Natural frequencies.83-217Mode saps

The Use of Affine Transformations in the Anoyea; (of Stability and Vibrations of Orthotropic Plates An analysis is presented for the free vibration of circular- J

GA. Oyibo segment-shaped membranes and plates of rectangular ortho-

54

tropy. A circular-segment-shaped membrane is formed on number of rectangular plates having oblique straight cracksan orthotropic rectangular membrane by fixing several seg- of various inclinations and lengths.

ments. With the reaction forces acting on the edges of an

actual membrane regarded as unknown harmonic loads, the

stationary response of the membrane to these loads is ex-pressed by the use of the Green's function. The force distri-

bution along the edges is expanded into Fourier series with 83-2222unknown coefficients, and the homogeneous equations forthe coefficients are derived by restraint conditions on the Resonant Acoustic Frequencies of Flat Plate Cascades

edges. W. Koch

DFVLR/AVA Institut f. Theoretische Stromungs-mechanik, Bunsenstrasse 10, D-3400 Gottingen, Fed.Rep. Germany, J. Sound Vib,, 88 (2), pp 233-242(May 22, 1983) 5 figs, 14 refs

83-2220Direct Method on the Determination of Eigenfre- Key Words: Plates, Cascades, Vortex-induced vibration,

ie Mod onbitrarily hpe d Patis of er Vortex shedding, Resonant frequenciesquencies of Arbitrarily Shaped Plates

K. Nagaya The analytical Wiener-Hopf solution is used to compute the

Dept. of Mech. Engrg., Faculty of Engrg., Gunma resonant acoustic frequencies of a fiat plate cascade as the

Univ., Kiryu, Gunma, Japan, J. Vib. Acoust. Stress natural frequencies of the system. For zero mean flow Machnumber and unstaggered cascades Parker's results are recov-

Rei. Des., Trans. ASME, 105 (1), pp 132-136 (Jan ered. New results are presented for staggered cascades and1983) 4 figs, 6 tables, 17 refs non-zero mean flow.

Key Words: Plates, Natural frequencies, Vibration analysis

A method for solving vibration problems of arbitrarily shaped

plates is presented. The frequency equation for determining 83-2223eigenfrequencies of arbitrarily shaped plates is given. Amethod of numerical calculation has been presented forfive examples of circular plates, elliptical plates, rectangular baffled, Finite Plates Using the FFTplates with rounded corners, and cardioidal plates. Numeri- E.G. Williamscal calculations are carried out for rectangular plates with Naval Res. Lab., Code 5133, Washington, DC 20375,semicircular sides, rectangular plates with rounded corners J. Acoust. Soc. Amer., 74 (1), pp 343-347 (Julyand cardioidal plates. The results obtained by this method are 1983) 4 figs, 11 refs |

compared with previously published results for typical casesof circular and rectangular plates.

Key Words: Disks (shapes), Plates, Vibrating structures,Noise generation, Fast Fourier transform

An iteration technique is described which numerically

evaluates the acoustic pressure and velocity on and near

83-2221 unbaffled, finite, thin plates vibrating in air, The technique

A Method for Obtaining Stress Intenty Factor by is based on Rayleigh's integral formula and its inverse. Theseformulas are written in their angular spectrum form so that

F.E.M. ad Its Application to Dynamic Problem the fast Fourier transform algorithm may be used to evaluate(Part 2, A Treatment for Mixed Mode Cracks) them. As an example of the technique the pressure on the

H. Wada, Y. Takagi, and T. Nishimura surface of a vibrating, unbaffled disk is computed and shown

Daido Inst. of Tech., Minami-ku, Nagoya, Japan, to be in excellent agreement with the exact solution using

Bull. JSME, 26 (215), pp 686-691 (May 1983) 12 oblate spheroidal functionL

figs, 3 tables, 23 refs

Key Words: Plates, Rectangular plates, Crack propagation

83-2224' . A new method recently proposed for obtaining stress inten- On-Line Spectral Control and Rotating Ciruar

sty factors for opening mode cracks has now been extendedto calculation of stress intensity factors for sliding mode Discs Using Thermal Membrane Streses

cacks. The usefulness of the method has been tested with a A. Rahimi

55

Ph.D, Thesis, Univ. of California. Berkeley, 170 pp Key Words: Cylindrical shells, Cylinders, Rolling friction,(1982) Fatigue life, Rolling contact bearings

DA8312942 The mechanics of contact of hollow cylindrical elements

were studied. The maximum contact stress is less for a hollowKey Words: Disks (shapes), Circular saws, Saws, Active vibra- cylinder than for a solid cylinder. A simple numerical methodtion Control is proposed to estimate the reduced contact stress by finding

an equivalent modulus of elasticity for the hollow cylinderRotating circular discs are widely used basic elements in for use in the contact stress equation.many different machines such as gas and steam turbines,

circular saws and computer memory discs, Large vibrationamplitude of circular discs due to transverse instability cancause inaccurate cutting in circular saws, head tracking errorin computer disc memories and failure of turbine wheels due RINGSto wheel-to-case contact. In this study, a new approach isdescribed where a feedback control system continuouslymonitors the stability of circular discs by means of inducedthermal membrane stresses in the plate. Although focused on 83-2227circular saws, this work has application in all the above sys- Inplane Vibrations of Circular Rings with a Radiallytems. Variable Thickness

H. Lecoanet and J. Piranda

Laboratoire de Mecanique Appliquie associe auCNRS, Facult( des Sciences, 25030 Besancon Cedex,France, J. Vib. Acoust. Stress Rel. Des., Trans.

83-2225 ASME, 105 (1), pp 137-143 (Jan 1983) 6 figs, 7 refsAn Investigation of Dual Mode Phenomena in a Mis-tuned Bladed Disk Key Words: Rings, Circular rings, Variable cros-section,

W.A, Stange and J.C. MacBain Galerkin method

Air Force Aero Propulsion Lab., Turbine EngineDiv., Wright-Patterson AFB, OH 45433, J. Vib. Results on inplane vibrations of circular rings with radially

variable thickness are presented. The problem is solved withAcoust. Stress Rel Des., Trans. ASME, 105 (3, pp the Galerkin method making use of the eigenfunctions of a

402-407 (July 1982) 13 figs, 1 table, 5 refs constant thickness ring. Good agreement is obtained betweenthe approximate results and those of the exact calculus or

Key Words: Blades, Disks (shapes), Tuning, Resonant re- experimental data.

sponse, Natural frequencies, Mode shapes IResults of an investigation addressing the effects of mistuningon the lower modes of vibration of a simple bladed-disk PIPES AND TUBESmodel are presented, The phenomena of dual modes, also (Also see Nos. 2213. 2214)known as mode splitting, is studied using holographic inter-ferometry and strain gage measurements under nonrotatingand rotating conditions.

83-2228

Study on Modeling of Pipe Whipping by Finite Ele-ment Method

SHELLS N. Miyazaki, S. Ueda, R. Kurihara, K. Saito, and R.Kato*Japan Atomic Energy Res. Inst., Tokyo, Japan,

83-2226 Rept. No. JAERI-M-9752, 47 pp (Oct 1981)

Mechanics and Behaviour of Holow Cylindrical DE82702914Members in Rolling ContactC S.C. Murthy and A.R. Rao Key Words: PIping systems. Whipping phenomena Finiteelement technique, Computer Programs

Mechanical Engrg. Dept., Indian Inst. of Tech., erMadras 600036 India, Wear, 87, pp 287-296 (1983) The general purpose finite element codes ADINA and MARC14 figs, 1 table, 15 refs were used to make s preliminary analysis for pipe whip tests

56

i --. . . . . nn I ll4

Performed with use of 4B, sch80 test pipes under saturated 83-2231water conditions. in the analyses, various models of the test The Effect of Approach Flow Direction on the Flow.pipe and the restraints were employed to study the effect of Induce Vibrations of a Triangular Tube Arraymodeling on pipe whip behavior. H.C. Yeung and D.S. Weaver

BHRA Fluid Engrg., Cranfield, Bedford, UK, J. Vib.Acoust. Stress Rel. Des., Trans ASME, 105 (1), pp76-82 (Jan 1983) 10 figs, 15 refs

Key Words: Tubes, Tube arrays, Heat exchangers, Fluid-83-2229 induced excitation

Experimental Studies of Dampi* and Hydrodynamic Water tunnel experiments were conducted on an equilateral

Mass of a Cylinder in Confined Two-phase Flow triangular array of tubes with a pitch ratio of 1.5. Eight tests

L.N. Carlucci and J.D. Brown were run with different array orientations so that the effects

Chalk River Nuclear Labs., Atomic Energy of Canada of incident flow direction on crosflow induced vibrations

Ltd., Chalk River, Ontario, Canada, J. Vib. Acoust. could be studied. Small amplitude vorticity response was

Stress Rel. Des., Trans. ASME, 105 (1), pp 83-88 observed for all orientations except the parallel triangular

(Jan 1983) 10 figs, 4 refs array.

Key Words: Cylinders, Tubes, Tube arrays, Heat exchangers,Fluid-induced excitation, Damping coefficients, Mass coeffi-cients DUCTS

This paper presents the results of experiments done to deter-mine the effects of cylinder mass and flow regime on thedamping and hydrodynamic mass characteristics of a cylinder 83-2232vibrating in simulated two-phase air-water flows. It was foundthat two-phase damping varied in inverse proportion to the Acoustic Loading in Planar Networkscombined cylinder and two-phase hydrodynamic masses. M. EI-Raheb and P. Wagner

Jet Propulsion Lab., California Inst. of Tech., Pasa-dena, CA 91109, J. Sound Vib., 88 (2), pp 151-162(May 22, 1983) 8 figs, 8 refs

Key Words: Ducts, Branched systems, Noise generation

83"-2230 The acoustic loading in a complex planar network of ducts isFlow-Induced Vibrations of Heat Exchanger U- determined by a method in which Green function surface

Tubes: A Simulation to Study the Effects of Asym- elements are used. The network consists of straight ducts,. metric Stiffness elbows and branched ducts. A transfer matrix technique is

SD.S. Weaver and 0. Koroyannakis developed in which each duct is treated separately and theDept. of Mech. Engrg., McMaster Univ., Hamilton, matrix of the influence coefficients is transformed to tri-

diagonal form allowing efficient Inversion.Ontario, Canada, J. Vib. Acoust. Stress Rel. Des.,Trans. ASME, 105 (1), pp 67-75 (Jan 1983) 12 figs,4 tables, 15 refs

Key Words: Tubes, Tube arrays, Heat exchangers, Fluid- 83-2233induced excitation, Stiffness effects, Experimental test data Wave Propagation in Strongly Curved Ducts

A water tunnel study was conducted to study the effect of D.H. Keefe and A.H. Benadeasymmetric stiffness on a parallel triangular array of tubes Dept. of Physics, Case Western Reserve Univ., Cleve-with a pitch ratio of 1.375. The tubes were cantilevered from land, OH 44106, J. Acoust. Soc. Amer.. 74 (1), PPrectangular support rods so that the stiffness, and hence 320-332 (July 1983) 8 figs, 3 tables. 14 refsnatural frequencies, ware different In directions parallel end

tranwerse to the flow. This arrangement was designed tosimulate the difference In in-plane and out-of-plane natural Key Words: Ducts, Curved ducts, Wave propagation, Soundfrequencies of curved tubes waves

57

A theoretical and experimental investigation is made of wave for the modal displacements of the cube. The effects ofpropagation in the long-wavelength limit in curved ducts of varying Poisson's ratio are also observed.both rectangular and circular cross section. The two-dimen-sional solution of the wave equation for propagation incurved rectangular bends is adapted for the case of a circularcross section. The wave admittance and phase velocity arecomputed in terms of integrals over the cross section of theduct in which there is a radial variation in flow. Experiments ELECTRIC COMPONENTSto measure the wave admittance and phase velocity arecarried out with semicircular segments from a baritone hornmusical instrument tuning slide.

GENERATORS

BUILDING COMPONENTS 83-2236(Also see No. 2345) Electromagnetic Forces on the End Windings of Large

Turbine Generators. ii. Transient Conditions

S.J. Salon, D.J. Scott, and G.L. Kusic83-2234 Rensselaer Polytechnic Inst., Troy, NY 12181, IEEESeimic Analysis of Slender Coupled Wagls Trans., Power Apparatus Syst., PAS-102 (1), ppJ.D. Aristizabal-Ochoa 14-19 (Jan 1983) 19 figs, 3 refsVanderbilt Univ., Nashville, TN 37235, ASCE J.Struc. Engrg., 109 (7), pp 1538-1552 (July 1983) Key Words: Generators, Electromagnetic excitation, Tran-

10 figs, 1 table, 11 refs sient response

A companion paper explained the basic concepts of endKey Words: Wafls, Reinforced concrete, Seismic analysis winding forces during steady state and gave examples of the

variation of force with power factor. This paper extends theThe dynamic response of multistory reinforced concrete analysis to transient operation. The fields and currents arecoupled walls was evaluated from the perspective of linear represented in the dqo reference frame. The fields are thenmodels based on response spectra, modal analysis, and projected onto the coil zones, and the cross-product is takenreduced effective stiffnesses. in order to find the force. Several examples are given in

which the instantaneous force is calculated.

83-2235On the Three-Dimensional Vibrations of the Canti- 83-2237levered Rectamgdar Paralelepiped Operational Inductances of Turbine-Generators byA. Leissa and Zhong-ding Zhang the Finite-Element MethodDept. of Engrg. Mech., Ohio State Univ., Columbus, S.H. Minnich, M.V.K. Chari, and J.F. BerkeryOH 43210, J. Acoust. Soc. Amer., 73 (6), pp 2013- General Electric Co., Schenectady, NY, IEEE Trans.,2021 (June 1983) 5 figs, 5 tables. 12 refs Power Apparatus Syst., PAS-102 (1), pp 20-27 (Jan

1983) 6 figs, 17 refsKey Words: Natural frequencies, Mode shapes, Parallelepiped,Cantilever beams, Ritz method Key Words: Finite element technique, Intake systems, Gen-

eratorsA solution is presented for the three-dimensional problem ofdetermining the free vibration frequencies and mode shapes A method is developed for calculating small-signal, terminal,for a rectangular parallelepiped which is completely fixed on operational inductances. The method is based on solutionsone face and free on the other fve faces. The Ritz method to the magnetic diffusion equation by the finite-elementis used, with displacement assumed in the form of algebraic method. To faithfully simulate the behavior of the rotor ironpolynomials. Convergence is studied. Numerical results are for small signal perturbations, measured values for Incre-given for the first five frequencies of each of the four sym- mental permeability are used. A finite-element grid tailoredmetry camsa of vibration, for five thick peralleleplped con- to handle the skin effect at frequencies up to 100 hertz isfigurations, Including the cube. Contour plots are exhibited developed.

58

I4

DYNAMIC ENVIRONMENT 83-2240 oNormal Mode Scaling and Phase Change at the

BoundaryT.C. YangNaval Res. Lab., Washington, DC 20375, J. Acoust.Soc. Amer., 74 (1), pp 232-240 (July 1983) 8 figs,

ACOUSTIC EXCITATION 8 refs(Also see Nos. 2172, 2309, 2311)

Key Words: Underwater sound, Sound propagation, Groupvelocity, Normal modes, Scaling

83-2238Coherent Attenuation of Acoustic Waves b air- The group velocities of normal modes are not independent

but are related to each other by a scaling law. The scalingCorrelated Random Distribution of Scatterers with law relates the frequencies of any two modes received at aUniform and Gaussian Size Distributions particular time (associated with a particular group velocity)V.K. Varadan, V.N. Bringi, V.V. Varadan, and Y. Ma by a scaling parameter. The scaling parameter is a constantWave Propagation Group, Dept. of Engrg. Mech., The for mode energies fully contained in the water column; in

Ohio State Univ., Columbus, OH 43210, J. Acoust. the ray picture, this corresponds to refracted only, andrefracted and surface reflected rays. Experimental data isSoc. Amer., 73 (6), pp 1941-1947 (June 1983) 10 analyzed to see how well the constant behaves for a variety

figs, 32 refs of frequencies and modes.

Key Words: Sound waves, Wave attenuation, Wave diffrac-tion

Acoustic wave attenuation due to multiple scattering in a 83-2241two-phase medium consisting of a fluid with embedded rigid, Slope Propagation: Mechanismn and Parameter Sens.-fluid, or elastic particles of varying sizes is discussed. The tivitiesformulation, involving the exciting and scattered fields of an R.A. Koch, S.R. Rutherford, and S.G. Payneincident acoustic plane wave, is based on the T-matrix meth-od. The propagation features of coherent waves in the mix- Applied Res. Labs., The tlniv. of Texas at Austin,ture are described by the dispersion equation which is derived Austin, TX 78712, J. Acoust. Soc. Amer., 74(1), ppby applying standard statistical approximations to the 210-218 (July 1983) 18 figs, 7 refsdiscrete random medium.

Key Words: Underwater sound

An adiabatic normal mode analysis is used to identify cylin-drical spreading, renormalization, bottom attenuation, differ-

83-2239 ential mode excitation and reception, and mode cutoff asEffect of Finite Ground Impedance on the Propaga- major physical mechanisms influencing underwater acousticEffeof Fit Grou Imednc propagation over slopes Propagation is sensitive to thetion ofAcoustic Pu s shallow water sediment attenuation but not to the slopeR, Raspet, H.E. Bass, and J. Ezell angle.U.S. Army Construction Engrg. Res. Lab., Box 4005,Champaign, I L 61820, J. Acoust. Soc. Amer., 74(1),pp 267-274 (July 1983) 9 figs, 19 refs

83-2242Key Words: Sound waves, Wave propagation, Explosions S-Matrix and Aeoustic Signal Structure in Simple andThe propagation of an acoustic transient in the vicinity of a Compound Waveguidesfinite impedance ground plane has been numerically simu- C.H. Wilcoxlated. A waveform characteristic of a small explosive charge Dept. of Mathematics, Univ. of Utah, Salt Lake City,was selected for analysIs. Puls waveforms and amplitudes UT, Rept. No. TSR-45, 43 pp (Dec 1982)were computed for propagation distances from 3 to 3000 m, AD-A 125 583for microphone heights from 0 to 30 m, and for flow reels- A 2tances from 10 to 1000 g 0n" s~. This study Indicatesthat finite ground Impedance can significantly affect acoustic Key Words: Wavegude analysis, Sound waves, Wave propega-pulses from explosI01 tion

59

_________'

This paper deals with the propagation of transient acoustic 83-2245fields in waveguides that consist of a semi-infinite cylinder Nonlinear Mixing of Surface Acoustic Waves Props-coupled to a resonant cavity or resonator. The walls of the gating in Opposite Directionswaveguide are assumed to be rigid. The sources of the tran-

sient sound fields, or signals, are assumed to be localized in a N. Kalyanasundaram

bounded portion of the waveguide and to act for a finite Dept. of Electronics and Communication Engrg.,interval of time. The goal of the work is to calculate such Regional Engrg. College, Tiruchirapalli 620015,acoustic signals and to analyze how their structure depends India, J. Acoust. Soc. Amer., 73 (6), pp 1956-1965on the sources and the geometry of the waveguide. (June 1983) 4 figs, 10 refs

Key Words: Sound waves, Wave propagation

The parametric mixing of two modulated surface acoustic

83-2243 waves propagating in opposite directions is studied with

Normal-Mode Propagation in Deep-Ocean Sediment reference to nonlinear signal processing applications by the

Channels: A Sequel coupled mode theory of nonlinear surface waves.

A.D. Williams, Jr.Dept. of Physics, Naval Postgraduate School, Monte-ray, CA 93940, J. Acoust. Soc. Amer., 73 (6), pp1985-1988 (June 1983) 1 fig, 7 refs 83-2246

Recommendations for the Acoustic Treatment ofKey Words: Underwater sound, Wave propagation, Sound Cumbica International Airportwaves Internacional de Engenharia, Sao Paulo, Brazil, Rept.

The present writer has discussed various aspects of propaga- No. I ESA-144-83, 70 pp (Jan 32, 1983)tion in sediment channels. A simplifying assumption was N83-19578that c., the speed of sound in the water, is constant every- OIn Portgueselwhere. In this sequel it is more realistically assumed that

c. decreases slowly and linearly with height above the

water-sediment interface. Consequently an acoustic barrier Key Words: Airports, Noise reduction

exists from the interface to, typically, 100-200 m above it.Equations are derived to describe the acoustic field both in The report presents the various alternatives that are recoin-

and above the barrier, and a long-known method yields the mended to keep the noise level in the airport terminal areasamplitude attenuation factor caused by leakage. within acceptable values. Discussions on the acoustic isola-

tion and absorption materials are presented indicating which

ones should be used and which ones should not. Adequatematerials for use in noise isolation are discussed.

83.2244Acoustic Shadowing by an Isolated SeamountN.R. Chapman and G.R. Ebbeson 83.2247Defence Research Establishment Pacific, FMO, Farfield Inflight Measurement of High-Speed Turbo.Victoria, British Columbia, Canada VOS 1B0, J. prop NoiseAcoust. Soc. Amer., 73 (6), pp 1979-1984 (June J.R. Balombin and I.J. Leoffler1983) 11 figs, 10refs NASA Lewis Res. Ctr., Cleveland, OH, Rept. No.

NASA-TM-83327, 19 pp (1982) )Presented at theKey Words: Underwate sound, Sound waves, Wave props- AIAA 8th Aeroacoustics Conf., Atlanta, Apr 11-13,gation 1983)

N83-21895Acoustic shadowing by an isolated sesmount has been N

studied by examining the multipath propegtion measure-ments obtained in a shot run that passed over the armount Key Words: Propeller noise, Noise measurement

peek. Source depths of 24 and 196 m were used in the

experiment. In the acoustic shadow, the propagation los A flight program was carried out to determine the variationfor the shallow 24-m shots increased by 10-15 dB over the of noise level with distance from a model high speed pro-

lose expected In the absence of the sieount. peller. Noise measurements were obtained at different dis-

A..

I.0

tances from a SR-3 propeller mounted on a JetStar aircraft, R.G. Cannwith the test instrumentation mounted on a Lear jet flown Grozier Technical Systems, Inc., 157 Salisbury Rd.,in formation. Brookline, MA 02146, NOISE-CON 83, Quieting the

Noise Source, Proc. of Natl. Conf. on Noise ControlEngrg., Massachusetts Inst. Tech., Cambridge, MA,Mar 21-23, 1983, pp 91-98, 8 figs, 3 refs

83-2248Paper Forms Skip Noise in Printers Key Words: Household appliances, Noise measurement,

L.W. Brehm Vibration tests

International Business Machines Corp., Dept. D68, Once the desirable sound level of a new product is established

P.O. Box 6, Endicott, NY 13760, NOISE-CON 83, by psychoacoustical means, there is a need for monitoring

Quieting the Noise Source, Proc. of Nati. Conf. on its sound level on the production line. The simple sound test.

Noise Control Engrg., Massachusetts Inst. Tech., when applied to the production line, may be either uselesslyaccurate or undesirably expensive. Using the sewing machineCambridge, MA, Mar 21-23, 1983, pp 61-70, 12 figs as an example, it has been shown, through extensive empiri-

cal work, that the sound test can be profitably replaced by aKey Words: Printing, Noise generation vibration test.

Noise radiating from paper forms generating from vibrationscaused by line spacing - or "skip" of the forms - and byimpact printing is investigated. These vibrations propagatethrough the paper and then from the curved surfaces of theforms as airborne noise. Where the forms exit to locationsoutside of the printer cover, this noise may be especially 83-2251offensive. Impact printing noise predominates in the 4 end An Analytical and Experimental Study of the Acous-8 kHz octave bands. tical Noise Produced by Machine Links

S. Dubowsky and T.L. MorrisUniv. of California, Los Angeles, CA 90024, J. Vib.

Acoust. Stress Rel. Des., Trans. ASME, 105 (3), pp

83-2249 393-401 (July 1982) 14 figs, 2 tables, 23 refs

Noise Sources and Noise Reduction in Office Ma.chines Key Words: Machinery noise, Noise generation, Mathematical

E. Schaffert models

BeSB GmbH Berlin, Holmholtzstr. 9, 100 Berlin 10, Noise from high-speed machine systems isan important engi-Fed. Rep. Germany, NOISE-CON 83, Quieting the nearing design problem. This study investigates a recently

Noise Source, Proc. of Nati. Conf. on Noise Control developed analytical technique for calculating the noiseEngrg., Massachusetts Inst. Tech., Cambridge, MA, generated by linkage-type machines based both on recently

r 2 , 1developed analytical methods for modeling the dynamicMar 21-23. 1983, pp 71-80, 9 figs response of machines and on classical acoustical theory.

This acoustical-dynamic modeling method is applied to anKey Words: Printing, Noise reduction experimental system with elastic elements and clearance

connections; the analytically predicted acoustical fields areThe principles of noise generationg by the printing systems compared to the measured noise.of office machines were investigated in several research pro-grams. The aim of these investigations was to reduce thegenerated noise by so called primary measures; i.e., measureswhich reduce noise generation at the source. This requiresthe accurate knowledge of noise generating mechanisms.

83-2252Theoretical and Experimsental Studies of the NoiseReduction of an Idealized Cabin Enlosre

83-2250 V. Cole. M.J. Crocker, and P.K. Raju IProductiom LIhe Noiuse Testing Using Vibration Tech. Paul S. Veneklasen and Associates, 1711 16th St.,

nilqes Santa Monica, CA 90404, Noise Control Engrg.,

61

20 (3), pp 122-132 (May/June 1983) 10 figs, 24 The space-time acoustic wave motion generated by a two-ref s dimensional, Impulsive, monopole line source in a fluid/

solid configuration with a plane boundary is calculated withthe aid of the modified Cagniard technique. The source is

Key Words: Enclosures, Noise reduction located in the fluid, and numerical results are presented forthe reflected-wave acoustic pressure, especially in those

In-cab noise environment of commercial vehicles and its regions of space where head wave contributions occur.effect on operators and passengers is of much concern.The airborne noise reduction that can be achieved by suchan enclosure is studied. Experimental measurements areperformed in a reverberation chamber supplied with broad-band white noise. The attenuation is measured in one-thirdoctave bandwidths whose center frequencies ranged from63 Hz to 20 kHz. From these results, conclusions are drawnas to the best ways of maximizing the noise reduction of 83-2255cabin enclosures. Time Domain Study of the Terminated Tranment

Parametric ArrayN.G. Pace and R.V. Ceen

School of Physics, Univ. of Bath, Claverton Down,Bath BA2 7AY, UK, J. Acoust. Soc. Amer., 73 (6),

83-2253 pp 1972-1978 (June 1983) 9 figs, 13 refs

Predictions of Low-Frequency Sound from theMOD-I Wind Turbine Key Words: Acoustic arrays, Impulse response. Time domain

R. Martinez, S.E. Windall, and W.L. Harris method

Dept. of Aeronautics and Astronautics, Massachusetts A spatial impulse response model of the parametric array isInst. of Tech., Cambridge, MA, Rept. No. SERI/ developed and used to give physical insight into its behaviorTR-635-1247, 61 pp (Dec 1982) when operated in a transient mode. Experimental measure-DE83004410 ments of the spatial dependence of the acoustic pressure

waveforms produced by the transient parametric array arecompared with the result of the convolution of the spatial

Key Words: Noise prediction, Noise source identification, impulse response with the specific pressure waveformsNoise-induced excitation, Wind turbines, Turbines used. Particular emphasis is given to the case where the

primary field is discontinuously terminated.The purpose of this project was to determine if aerodynamicnoise mechanisms are associated with the acoustic noise situ-ation that results from the operation of the MOD-1 windturbine. The possible sources of aeroacoustic noise studiedwere steady blade loads, unsteady blade loads due to windshear, and unsteady loads on the blades as they pass throughthe tower wake, Mathematical models that were used tostudy these noise sources re described. 83-2256

Hehuholtz Resonators. 1975 - April. 1983 (Citationsfrom the International Information Service for thePhysics and Engineering Communities Data Base)NTIS, Springfield, VA, 68 pp (Apr 1983)PB83-861930

83-2254~Genration of Aeonatic Waves by an Impulsive Line Key Words: Acoustic measurement, Acoustic Impedance,Source in a Fluid/Solid Configuration with a Plane Helmholtz resonators, BibliographiesBoundaryA.T. deHoop and J.H.M.T. Van Der Hijden This bibliography contains 54 citations concerning the mea-Schlumberger-Doll Research, P.O. Box 307, Ridge- surement and analysis of ecoustki, Impedance utilizing Helm-field, CT 06877, J. Acoust. Soc. Amer., 7 (1), holtz resonetors Two-dimensional Helmholtz resonators,333-342 (July 1983) 8 figs. 3 tables, 14 refs biological effects of acoustical stlmulli, Helmholtz resonator

utilization for continuous pipe flow measurement, detectionand analysis of acoustic room insulation, viscous losses, end

Key Words: Sound generation, Line source excitation, Inter- optoacoustic phenomena are among the topica discussed.face: solid-fluid Applications and performance evaluations are considered.

62

4 -

83-2257 W.B. McClureAcoustic Groud Impedance Meter Air Force Inst. of Tech., Wright-Patterson AFB, OH,A.J. Zuckerwar Rept. No. AFIT/Ci/NR-83-6T, 123 pp (Jan 1983)NASA Langley Res. Ctr_, Hampton, VA 23665, J. AD-A126 919Acoust. Soc Amer., 73 (6), pp 2180-2186 (June1983) 7 figs. 1 table, 25 refs Key Words: Interaction: shock waves-boundary layer, Experi-

mental test data. ScalingKey Words: Acoustic impedance. Ground motion. Helm-holtz res Aotors An experimental study was carried out on a three-dimension-

al shock wave/turbulent boundary layer flow-fie(d generated

A compact, portable instrument has been developed to mea- by sharp fin with en unswept leading edge at a 10deg angle-

sure the acoustic impedance of the ground, or other surfacas, of-attack to the incoming flow. The objectives of this study

by direct presaure-volume velocity measurement. A Helm- were to learn more about the structure of this type of inter-

holtz resonator, constructed of heavy-welled stainless steel action, to examine the scaling of the resulting flow-field,

but open at the bottom, is positioned over the surface having and to obtain detailed data et with which to compare

the unknown impedance. The prototype instrument can numerical computations

measure specific ground impedance at normal incidence upto 50 times the specific impedance of air. Detailed designcriteria end results of measurements on an uncultivated grassfield ers presented.

83-2260Eartsqusde Egioneering Research - 1982Committee on Earthquake Engrg. Res., National Res.

83-2258 Council, Washington, D.C., Rept, No. CETS-CEER-Acoutic High-Frequency Scatteriug by Elastic Cyihn- 001B, 281 pp (1982) and Rept, No. CETS-CEER-drkil Shells 001A, 94 pp (1982)J.W. Dickey, D.A. Nixon, and J.M. D'Archangelo PB83-176032 and P883-176024David Taylor Naval Ship R&D Ctr., Annapolis, MD21402, J. Acoust. Soc. Amer., 74 (1), pp 294-304 Key Words: Seismic design, Interaction: structure-fluid

(July 1983) 11 figs, 19 refsTwo questions were addressed: what progress has research

Key Words: Shells, Cylindrical shells, Acoustic scattering produced in earthquake engineering and which elementsof the problem should future earthquake engineering pursue.

Acoustical scattering resulting from a high-freuqency plane- Examined and reported in separate chapters of the report:

wave incident upon an infinite aluminum circular cylindrical applications of past research, assessment of earthquakeshell immersed in and filled with water is determined by hazard, earthquake ground motion, soil mechanics and earthapplying the Sommerfeld-Watson transformation to the structures, analytical and experimental structural dynamics,

classical Rayleigh normal-mode series solution. The result- earthquake design of structures, seismic interaction ofstructures and fluids, social and economic aspects, earth-ing contour integrals are computed by both the saddle point queeniergedcto.reahinJp.

"0 i method and by summing residues over poles which corre- quake engineeing education, reseach in Japan.

spond to the zeros of a 6 x 6 determinant resulting fromsatisfying the necessary buundery conditions. Emphasis isplaced on the transitions in the scattering characteristics asthe shell goes from a solid cylinder to a thin-walled ihell,

83-2261Dysainic Analy -i of Landiag Impact

SHOCK EXCITATION Engrg. Div., Israel Aircraft Industries Ltd., Tel-Aviv,(Also see No 2316 I 2345) Israel, Rept. No, IAITIC-82-1006, 12 pp (Jan 1982)

PB83-188383

832259 Key Words: Lending gwr, Impact shock, Shock absorbers

Experimental Study into the Scaling of an Umwept " Th is paper decribels a series of analyses that were develop edSharp-Fi.-Geseratd ShoeW rhluileet Boudry to calculate loads end dioplacements of landing gear sy sLayer iteraefio having a variety of configurations, The mathematical models

63

_____I;

" { .--- _____5

i • I I41 .-

used in these analyses simulate the dynamics of landing 83.2264impact and account for such effects as: nonlinear shock- Dynamic Stability of a Vibrating Hammerabsorber stiffness; hydraulic damping of the shock-absorber; J. Inoue and S. Miyaurashock-absorber internal friction; fore-and-oft flexibility ofthe landing gear leg; tire/ground friction characteristics; Kyushu Univ., Higashi-ku Fukuoka, Japan, J. Vib.wheel spin-up effects. By means of numerical integration, Acoust. Stress Rel. Des., Trans. ASME, 105 (3), pptime-histories of landing gear loads and displacements are 321-325 (July 1983) 8 figs, 3 refscalculated.

Key Words: Hammers, Vibrating structures, Energy absorp-tion, Motors, Dynamic stability

This paper deals with the stability of motion of an elasticallysuspended vibrating hammer that impacts upon an energyabsorbing surface referring to the dynamical interaction

83-2262 between a vibrating hammer and a motor.

Cyclic Loading of Spirally Reinforced ConcreteS.P. Shah, A. Fafitis, and R. ArnoldNorthwestern Univ., Evanston, IL 60201, ASCE J.Struc. Engrg., 109 (7), pp 1695-1710 (July 1983) 83.226514 figs, 3 tables, 20 refs Transfer Functions and Impulse Responses of Rigid

and Elastic Spheres (Fonctiona de tranufert etr-Key Words: Reinforced concrete, Seismic excitation, Cyclic a E lastic S phtres de e et realoading ponses impulsionnelles de sphi.m~ rigides et Qls-

tiquea)

The concept of the envelope curve which was based primarily C. Gazanhes, JP. Sessarego, J.P. Herault, and J.on plain concrete is extended to confined concrete subjected Leandreto cyclic loading. Spirally confined normal weight and light Laboratoire de Mecanique et d'Acoustique (CNRS),weight concrete specimens are subjected to stress and strain BP 71, F-13277 Marseille Cedex 9, France, Acustica,cycling loadings at low as well as high strain rates. Analyticalexpressions are developed to predict the envelope curve as 52 (5). pp 265-272 (Apr 1983) 7 figs, 2 tables, 11well as the peak strength and the corresponding strain. refs

(In French)

Key Words: Spheres, Impulse response, Transfer functions

The transfer functions and the impulse responses of rigid andelastic spheres are investigated for values of the reduced

83.2263 parameter ka from 0.2 up to 28. These functions are calcu-Properties of Concrete Subjected to Impact lated initially from modal theory and then verified experi-mentally from back-scattering measurements. For rigidW. Suaris and S.P. Shah spheres some examples are given of impulse responses derivedUniv. of Miami, Coral Gables, FL, ASCE J. Struc. by dlfferent techniques and the influence of creepngwavesisEngrg., 109 (7), pp 1727-1741 (July 1983) 8 figs, discussed. For elastic spheres a smoothed Impulse response3 tables, 20 refs is computed by taking the inverse Fourier transform of the

transfer function.

Key Words: Concretes, Impact response, Impulse response,Dynamic tests, Experimental test dat

For rational design of concrete structures subjected to im- VIBRATION EXCITATIONpact and impulsive loading, the constitutive properties of (Also gee NoL 2164, 2235, 2311)concrete over a wide range of strain rates are required. Withthis aim In mind, concrete and fiber reinforced concretebeams were tested in a drop-weight, instrumented impacttesting machine. During the Impact event, loads, deflections 83-2266and strains were monitored. The influence of matrix mix Deugn of the Fitter Suppremon System for DASTproportions, relative humidity during curing and the type

of fibers (steel, polypropylene and glass) on impact prop- ARWJRerties era presented. J.R. Newsom, A.S. Pototzky, and I. Abel

64

4-

NASA Langley Res. Ctr., Hampton, VA, Rept. No. A theoretical description of sources of vibration and howNASA-TM-84642, 15 pp (Mar 1983) (Presented at they are measured is summarized. Discrepancy between thethe AIAA/ASME/ASCE AHS 24th Struct., Struct. (theoretically) desirable information and commonly avail-DCeable data is hilhlighted. A description of the transmissionDyn. and Mater. Conf., Lake Tahoe, NV, May 2-4, path in terms of dispersion, multipath propagation and1983) reverberation that affect the transmitted vibration signal isN83-21840 considered.

Key Words: Flutter, Active flutter control, Aircraft

The design of the flutter suppression system for a remotely-piloted research vehicle is described. The modeling of theaeroelastic system, the methodology used to synthesize thecontrol law, the analytical results used to evaluate the controllaw performance, and ground testing of the flutter suppres- 83-2269sion system on-board the aircraft are discussed. The major Investigation of Limit Cycle Response of Aerody-emphasis is on the use of optimal control techniques am- namic Surfaces with Structural Nonlinearitiesployed during the synthesis of the control law. R.P. Briley and J.L. Gubser

McDonnell Douglas Astronautics Co., East St. Louis,MO, Rept. No. AFOSR-TR-83-0232, 65 pp (Oct 1,1983)

83-2267 AD-A127 140

Nonlinear Extenmonul Vibrations of Quartz Rods Key Words: Aerodynamic stability, Limit cycle analysis,H.F. Tiersten and A. Ballato Nonlinear theoriesDept. of Mech. Engrg., Aeronautical Engrg. andMechanics, Rensselaer Polytechnic Inst., Troy, NY Aerodynamic surface design must often account for the

12181, J. Acoust. Soc. Amer., 73 (6), pp 2022-2033 presence of structural nonlinearities induced by freeplay in(June 1983) 5 figs, 21 refs the support structure and/or control actuators. During this

study, application of asymptotic expansion methods topredict the limit cycle behavior of aerodynamic surfaces with

Key Words: Nonlinear vibration, Longitudinal vibration, structural nonlinearities was investigated.Quartz crystals, Piezoelectricity

The one-dimensional scalar differential equation describingthe extensional motion of thin piezoelectric rods is obtainedfrom the general nonlinear three-dimensional description.Only the elastic nonlinearities are considered. The relationsbetween the quadratic and cubic coefficients of the rod andthe fundamental anisotropic elastic constants of various 83.2270orders are derived. Aerodynamics of Airfoils Subject to Three-Dimen-

sional Periodic GustsH. Atassi

Dept. of Aerospace and Mech. Engrg., Notre Dame

83-2268 Univ., IN, Rept. No. AFOSR-TR-83-0231, 68 pp

Vibration Transmisson in Machine Structures (July 1982)R.H. Lyon AD-A 127 043

Massachusetts Inst. of Tech., Dept. of Mech. Engrg.,Cambridge, MA 02139, Noise Control Engrg.,2 2(3), Key Words: Airfoils, Wind-induced excitation, Turbulence.

pp 92-103 (May/June 1983) 14 figs, 25 refs Turbomachinery

This report outlines research on unsteady aerodynamics andKey Words: Vibration transfer, Transfer functions, Machine- stability analysis of turbomachine components and Its role-ry vance to ongoing technological developments In turboma-

chine design. The main topic of this research is the unsteadyThere is growing interest in the use of vibration signals for aerodynamics of lifting airfoils subject to three-dimensionaldignostics and phase retention is very Important in this area. gusts.

65

83.2271 A method of mathematical substitution is presented byRotary Oscations of" a Spheroid in an Incompres- which the dynamic properties of a four-mass mechanical

tary Oscillrn of aSphersystem can be evaluated quickly in a closed form, eliminatingsble Micropola Fluid the need for numerical iterations.

S K. Lakshmana Rao and T. K.V. lyengarDept. of Mathematics, Regional Engrg. College,Warangal-506004, India, Intl. J. Engrg. Sci., 21 (8),pp 973-987 (1983) 5 refs

Key Words: Spheres, Vibrating structures, Fluids 83-2274

The flow generated by rotary oscillations of a spheroid Parametrically Excited Multidegree-of-Freedom Sys-

(prolate and oblate) in incompressible micropolar fluid is tes with Repeated Frequenciesdiscussed. The velocity and microrotation components are A.H. Nayfehdetermined explici.v in terms of spheroidal wave functions Dept. of Engrg. Science and Mechanics, Virginia Poly-and are expressed in ,nfinite series form. The couple on the technic Inst. and State Univ., Blacksburg, VA 24061,oscillating spheroid is evaluated and numerical studies areundertaken to examine the effects of the geometric perem- J. Sound Vib., 88 (2), pp 145-150 (May 22, 1983)eter and material constant parameters of the fluid. 8 refs

Key Words: Multidegree-of-freedom systems, Parametricexcitation

83.2272 An analysis is presented of the linear response of multidegree-An Efficient Techiue for the Approximate Analys of-freedom systems with a repeated frequency of order three

to a harmonic parametric excitation. The method of multipleof Vibrompact scales is used to determine the modulation of the amplitudes

R.K. Miller and B. Fatemi and phases for two cases: fundamental resonance of the

Dept. of Civil Engrg., Univ. of Southern California, modes with the repeated frequency and combination reso-

Los Angeles, CA 90007, J. Vib. Acoust. Stress Rel. nance involving these modes and another mode. Conditions

Des., Trans. ASME, 105 (3), pp 332-336 (July 1983) are then derived for determining the stability of the motion.

6 figs, 11 refs

Key Words: Vibro-impact systems, Base excitation, Harmonicexcitation

An approximate solution procedure is presented for a class of 83-2275 Isteady vibro-impct problems consisting of adjacent struc- Stability Boundary for Pseudo-Random Parametrictures separated by a gap and subjected to harmonic base Excitation of a Linear Oscillatorexcitation. The procedure is based on a weighted mean-square linearization technique, and is capable of substantial D. Watt and A.D.S. Barrreduction of computational effort over that required for an The University, Dundee, DD1 4HN, UK, J. Vib.exact numerical simulation. A detailed analysis of an example Acoust. Stress Rel. Des., Trans. ASME, 105 (3), ppproblem is presented together with a comparison of results 326-331 (July 1983) 8 figs, 1 table, 24 refswith an exact solution.

Key Words: Parametric excitation, Oscillators

Stability bounds are outlined for the null solution of theequation describing the response of a linear damped oscilla-

83.2273 tor excited through periodic coefficients, the excitation

Quik Vibration Analys of Four-Ms Systems being a form of Rice noise comprising equal amplitude sinu-

R. Errichello soids with frequencies at equal Intervals in the vicinity oftwice the natural frequency of the system, but with pseudo-

Gear, Con(13)ltant10,EARTEC, AlJny , Ma. 1 random initial phaas. Stability was investigated by the

Des., 55(13). pp 110, 112, 115 (June 9. 1983) 1 fig monodromy matrix method, which is exact apart from

errors due to numerical Integration, and by the approximate

Key Words: Vibration analysis, Multi-degree of freedom method due to Struble, which replaces the dependent vari-

systems able by Its amplitude and a phase variable.

66

83-2276 the AIAA/ASME/ASCE/AHS 24th Struct.. Struct.Turbulent Pressure-Velocity Measurements in a Fully Dyn. and Mater. Conf., Lake Tahoe, NV, May 2-4,Developed Concentric Annular Air Flow 1983)R.J. Wilson and B.G. Jones N83-20912RAS Div., Argonne Natl. Lab., Argonne, IL 60439,

J. Vib, Acoust. Stress Rel. Des., Trans. ASME, 105 Key Words: Airfoils, Flutter, Harmonic excitation, Geo-(3), pp 345-354 (July 1983) 23 refs, 2 tables, 26 refs metric effects, Transient pulse technique

A transient pulse technique is used to obtain harmonic forcesKey Words: Fluid-induced excitation from a time-marching solution of the complete unsteady

transonic small perturbation potential equation, The un-An experimental study of the fluctuating velocity field and steady pressures and forces acting on a model of the NACAthe fluctuating static wall pressure in an annular turbulent 64A010 conventional airfoil and the MOB A-3 supercriticalair flow system with a radius ratio of 4.314 has been con- airfoil over a range of Mach numbers are examined in detail.ducted. The study included direct measurements of the meanvelocity profile, turbulent velocity field and fluctuating staticwall pressure from which the statistical values of the turbu-lent intensity levels, power spectral densities of the turbulentquantities, and the cros-correlation between the fluctuating 83-2279static wall pressure and the fluctuating velocity field in thecore region of the flow were obtained. "Non-Linear Normal Modes7 and the Generaled

Ritz Method in the Problems of Vibrations of Non-Linear Elastic Continuous SystemsW. Szemplinska-Stupnicka

83-2277 Inst. of Fundamental Technological Ras., PolishFlow Instability Due to a Diameter Reduction of Academy of Sciences, 00-049 Warsaw, Swietokrzyska

Limited Length in a Long Annular Passage 21, Poland, Intl. J. Nonlin. Mech., 18 (2), pp 149-165M.W. Parkin, E.R. France, and W.E. Boley (1983) 8 figs, 25 refs

United Kingdom Atomic Energy Authority, Seascale,Cumbria CA201PF, UK, J. Vib. Acoust. Stress Rel. Key Words: Mode shapes, Ritz methodDes., Trans. ASME, 105 (3), pp 355-360 (July In the study of natural vibrationsof nonlinear elastic systems1983) 13 figs, 5 refs it is shown that the mode shape of the vibration can vary

with the amplitude as well as the frequency, and that theKey Words: Fluid-induced excitation, Nuclear reactor coin- amplitude-frequency relation is strongly affected by con-ponents straints imposed on the mode shape in an approximate

solution, A method is developed which assumes the approxi-Flow in an annular passege is a common feature in the fuel mate solution in the form of a truncated series in which,channels of the UK advanced gas cooled reactors, and in instead of the set of coefficients, the set of functions ofsome cases has required investigation to avoid or reduce spatial variables is unknown and then determined by a pro-flow-induced vibration of reactor components, A number cedure that can be regarded as a generalization of the Ritzof studies of vibration induced by annular flow are briefly method.reviewed In the first part of this paper. The second part ofthe Paper describes the investigation of the most recentlyrecognized problem of this type, which is a flow instabilitycaused by a diameter reduction of limited length In a longannulus. A method of eliminating the mechanism is also MECHANICAL PROPERTIESdescr ibed.

DAMPING83-2278 (Also see No. 2200)

Airfoil Shape and Thickness Effects on TransonicAirloads and FlutterS.R. Bland and J.W. Edwards 83-2280NASA Langley Res. Ctr., Hampton, VA, Rept. No. Protection of Continuous Structures Againmt Vibra-NASA-TM-84632, 10 pp (Mar 1983) (Presented at tionshy Active Damping

.61

1-4-

E. Luzzato and M. Jean excitation is analyzed. The residual shock spectrum is also

Centre National de la Recherche Scientifique, Labora- evaluated when a rectangular, triangular or half sine wave

toire de Mecanique et d'Acoustique, 31, Chemin pulse is applied to the oscillator.

Joseph-Aiguier, Marselle, France, J. Vib. Acoust.Stress Rel. Des., Trans. ASME, 105 (3), pp 374-381(July 1983) 16 figs, 12 refs

Key Words: Damping, Active damping, Vibration damping,Continuous systems, Viscoelastic properties, Flexural vibra-tion, Beams, Plates 83-2283

Characterization of High Temperature PolymericThe problem of active damping of vibrations of a continu- Damping Materialsous viscoelastic structure is studied, and a general method of R.P Chartoff, 1.0. Salyer, M.L. Drake, et alcomputation of the control system is developed. A mechani-cal model for this structure, sources of perturbing vibrations, Univ. of Dayton Res. Inst., Dayton, OH 45469, Rept.the control system, and different absorption criteria arv No. AFWAL-TR-82-4185, 246 pp (Jan 1983)defined. Numerical results simulating the behavior of flexuralvibrations in a rectangular plate, which is simply supported Key Words: Vibration damping, Energy absorption, Polymersalong the whole boundary, are presented for three differentabsorption criteria, thus permitting a quick evaluation of An exploratory development program was carried out to findthe comparative effectiveness of the chosen criteria, polymer systems that are effective energy absorbers for

vibration damping purposes in the temperature range from3000 F (149C) to 700OF (3710 C). The study concentratedon aromatic backbone structures of the type that wereknown to have good thermal stabilities and glass transitionsfalling in the temperature range of Interest. Among the

83-2281 types of polymers considered were various polyimide, poly-Power Turbine Dynamics -- An Evaluation of a Shear- sulfone, ATX, and silicone materials.

Mounted Elastomeric DamperE.S. Zorzi, J. Walton, and R. CunninghamMechanical Technology, Inc., Latham, NY, ASME

Paper No. 83-GT-228

Key Word,: Dampers, Elastomeric dampers, Rotating ma-chinery 83-2284

Comparison of Equivalent Viscous Damping andThis successful application of elastomeric damper technology Nonlinear Damping in Discrete and Continuouspresents an opportunity to reflect upon the many uses of Vibrating Systemselastomers as alternatives to conventional squeeze-film J.P. Bandstradampers.

Div. of Engrg. Tech., Univ. of Pittsburgh at Johns-town, Johnstown, PA 15904, J. Vib. Acoust. Stress

4 Rel. Des., Trans. ASME, 105 (3), pp 382-392 (July1982) 3 figs, 8 tables, 24 refs

83-2282E o m oso e Key Words: Damping, Viscous damping, Nonlir ar damping,Effect of Damping on Shock Response Spectrum Continuous systemsY MatsuzakiNational Aerospace Lab., Tokyo, Japan, Rept. No. The study of nonlinear damping in vibrations is motivatedNAL-TR-739T, ISSN-0389-4010, 10 pp (Sept 1982) by the desire to represent and predict real responses more

N83-19127 accurately than allowed by the limitations of linear analysis,since observed phe",,mena are, in general. actually nonlinearin nature. The scop ,if this paper is to compare the normal

Key Words: Damping effects, Shock response spectra engineering methods .f including the effects of nonlineardamping to more exact methods of solution so that the U

The shock response spectrum of an oscillator with any range of applicability of the normal methods may be knownamount of damping which is subjected to an arbitrary shock and the limitations of linear analysis more fully understood.

68

I--,---I I:I-

FATIGUE machi, Nagasaki, 852, Japan, Bull. JSME, 26 (215),

(Also see No. 2202) pp 692-699 (May 1983) 17 figs, 11 refs

Key Words: Fatigue life, Crack propagation

83.2285 Mode III fatigue crack growth was studied using cylindricalspecimens with ring-shaped edge cracks under reversed tor-The Determination of the Failure of Mac ine Ele. sion. Cracks grew locally in Mode I making small branchesments during Operation by Means of Galvanic Copper but their macroscopic growth direction was perpendicularPlating (Untersuchung des Enanudungszustandes von to the specimen axis. The crack depth was successively esti-Maachinenelementen wa1rend des Betriebes mit mated by the compliance calibration method and the growthHillfe der Galvaniachen Verkupferung) rate of torsional cracks was related to the applied stress

intensity factor range At(, IS.G. Kerimov and O.A. Mamed-ZadeAserbaidshanische Hochschule f. Erdl und Chemie,,M. Asisbekow," UdSSR, Baku, Maschinenbautech-nik, 32 (4), pp 180-182 (Apr 1983) 6 figs, 1 table, ELASTICITY AND PLASTICITY5 ref s(In German)

83-2288

Key Words: Fatigue life, Machinery components Dynamic Young's Moduli of Some CommerciallyAvailable Polyurethanes

A.galvanic copper plating method is presented, which can R.N. Cappsbe used for the determination of fatigue of machine elements Naval Res. Lab., Underwater Sound Reference De-during operation. The applicability and accuracy of the tachment, P.O. Box 8337, Orlando, FL 32856, J.method is illustrated by an example. Acoust. Soc. Amer., 73 (6), pp 2000-2005 (June

1983) 15 figs, 9 refs

Key Words: Elastomers, Modulus of elasticity, Resonancetests, Viscoelastic properties, Wave propagation

83-2286 The Young's modulus and loss tangent were measured inFatigue Crack Propagation in an HSLA Steel (MF-80) air for a number of commercially available polyurethanes. Ain Air and in Salt Water resonance technique was used for measurements over theS.J. Gill and T.W. Crooker approximate frequency range 102 to l0 Hz and the approx-Naval Res. Lab., Washington, DC, Rept. No. NRL- !matt, temperature range 40 to -5*C. Master curves and

Williamh ,.andel-Ferry shift constants were determined forMR-5048, 25 pp (Apr 1983) the materials tested. The automated data acquisition systemAD-A 127 423 used is described. The experimental procedure was found

to be a reliable method for determining the viscoelasticKey Words: Fatigue life, Crack propagation constants for extensional wave propagation in elastomeric~materiels,Fatigue crack propagation was studied in MF-80 HSLA

steel in ambient room air and in 3.5 percent NaC1 saltwater. Region-Il fatigue crack growth rate (da/dN) data

j were obtained at two load ratios. 83-2289

Frictional Slip Between a Layer and a Substrate Dueto a Periodic Tangential Surface ForceM. Comninou and J.R. BarberUniv. of Michigan, Ann Arbor, MI, 48109, Intl. J.

83-2287 Solids Struc., 19 (6), pp 533-539 (1983) 7 figs, 9 refs

Growth of Ring.&aped Edge Cracks under ReversedTorson Fatige Key Words: Stick-slip response, Fretting corrosion

T. Matake, Y. I mai, and T. Takase A solution is given for the problem of an elastic layer pressed VDept. of Mech. Engrg., Nagasaki Univ., Bunkyo- against an elastic half-plane end ubjected to a tangential

69EMISIO

force varying periodically in time. A loading cycle which 83-2292initially causes localized slip is followed through unloading The Determination of the Elatodynamic Fieldsand reloading. A limiting load is established below which the of an Ellipsoidal Iniomogeneitysteady state of the interface does not involve slip. L.S. Fu and T. Mura

Dept. of Engrg. Mechanics, Ohio State Univ., Colum-bus, OH 43210, J. Appl. Mech., Trans. ASME, 50

(2), pp 390-396 (June 1983) 8 figs, 21 refs

83.2290 Key Words: Wave propagation

Further Studies on Dynamic Crack Branching Elastic fields of a single ellipsoidal inhomogeneity embedded

M. Ramulu, A.S. Kobayashi, B.S.-J. Kang, and D.B. in an infinite elastic matrix subjected to plane time-harmonic

Barker waves are studied by employing the concept of eigenstrain

Dept. of Mech. Engrg., Univ. of Washington, Seattle, and the extended version of Eshelby's method of equivalent

WA, Rept. No. UWA/DME/FTR-82/46, 26 pp (Mar inclusion. Using the dynamic version of the Betti-Rayleighreciprocal theorem, an integral representation of the dis-

1983) placement field, due to the presence of inhomogeneity, is

AD-A126 444 given in terms of the eigenstrains.

Key Words: Crack propagation

Crack branching represents one extreme of the large range of

dynamic crack propagation behaviors and has been the sub-

ject of numerous theoretical and experimental investigations. 83-2293A crack curving and a branching criteria based on the direc- Generalized Reaction Principles and Reciprocitytional stability of a propagating crack was recently derived. Thered rea vtion s and Reion-Theorems for the Wave Equations, and the Relation-

ship Between the Time-Advanced and Time-RetardedFieldsN.N. Bojarsk i

WAVE PROPAGATION J. Acoust. Soc. Amer., 74 (1), pp 281-285 (July(Also see Nos. 2238,2239, 2240, 2241, 2242,2243,2244, 1983) 5 refs

2245, 2258, 2303)Key Words: Wave equation, Reciprocity principle

Generalized reaction principles and generalized reciprocity Itheorems for the scalar and vector wave equations are de-

83-2291 rived. It is shown that the reaction principles of RumseyOn the Structure of the Directivity for Scattering by and the reciprocity theorems of Welsh are special cases ofa• Rigid Strip these generalized reaction principles and generalized recip-a rocity theorems. The generalized reciprocity theorems are

cast in terms of the time-retarded fields only, as well as in

Max-Planck-lnstitut f. Str6mungsforschung, B~ttin- termsof the time-retarded and time-advanced fields.

gerstrasse 4-8, D-3400 Gr6ttingen, West Germany,Acustica, 52 (5), pp 273-278 (Apr 1983) 4 figs, 6refs

Key Words: Wave diffraction 83-2294

Recant studies on scattering problems lead to the result that Propagation of Love Waves on a Cylindrical Earthfor scattering of a plane wave by a rigid strip the directivity, Modelwhich is a function of the angle of incidence and the angle of A. Chattopadhyay and N.P. Mahataobservation, may be expressed in terms of a function of one Dept. of Physics and Mathematics, Indian School ofvariable only. This feature is not obviously shown by the De

classical representations of the directivity. In this paper the Mines, Dhanbad-826004, India, J. Acoust. Soc.

relation between the long-known solutions and the recent Amer, 74 (1), pp 286-293 (July 1983) 5 figs, 14results is investigated. refs

70

' ..

Key Words: Elastic waves, Wave propagation, Earth mod- driven by two independent random signals. Special softwareels routines handle the vibration data in the Fourier analyzer

system. In addition to conventional modal analysis, a data-The effects of different radial inhomogeneities on the propa- management program called Dual Shaker organizes andgation of Love waves over a circular cylindrical surface are keeps track of the exciter end response data. Also, softwarediscussed and distinctly marked on the dispersion curves, called the Enhanced Measurement for Experimental TestingThe phase velocity due to an assumed type of inhomogeneity IEMET) expands the data capacity of the analzyer.becomes larger or smaller than that for a homogeneous layeraccording to whether the value of kh is more or less than0.625. Using the above deduction and the perturbation tech-nique, the modified dispersion equation of Love waves in anonhomogeneous crustal layer with corrugated surface are 83-2297obtained. Modal Density -A LiUiting Factor in Analysis

G.F. LangFox Technology Corporation, Westwood, NJ, S/V,

83.2295 Sound Vib., 17 (3), pp 20-22 (Mar 1983) 10 figs

Antiplane Strain Harmonic Waves in Infinite, Elastic, Key Words: Modal analysis, Parameter identification tech-

Periodically Triple-Layered Media n iquesK. Karim-PanahiDiv. of Applied Mechanics, Stanford Univ., Stanford, Modal density describes the frequency proximity of adjacentCA 94301, J. Acoust. Soc. Amer., 74 (1), pp 314-319 modes, and thus their susceptibility to precise measurement.

(July 1983) 9 figs, 11 refs At low density an experimental modal analysis is limitedby the frequency resolution of the analysis system. At highdensity, a structure's dynamics defy modal decomposition

Key Words: Layered materials, Wave propagation, Wave by signal processing techniques, alone; zoom processingattenuation, Harmonic waves proves unable to separate overlapping modal bandwidths and

spatial decomposition must be employed. Between thesePropagation of horizontally polarized shear waves in peri- extremes, the analysis is limited by the sophistication andodically triple-layered, elastic medium is studied by using precision of the modal parameter identification algorithmsFloquet's theorem. The dispersion relation is characterized, employed.The propagation and attenuation of harmonic waves insideand outside the Brillouin zones are identified. Variation ofthe spectrum following the modification of the comparativemechanical properties of the three layers is also examined.

83-2298Selective Modal Analys in Power Systems. FinalReportEXPERIMENTATION G.C. Verghese, I.J. Perez-Arriaga. F.C. Schweppe,

and K.W.K. Tsai1. Electric Power Systems Engrg. Lab., MassachusettsInst. of Tech., Cambridge, MA, Rept. No. EPRI-

MEASUREMENT AND ANALYSIS EL-2830, 98 pp (Jan 1983)(Also see Nos, 2268,2314,2315) DE83901586

83-2296 Key Words: Modal analysis, Dynamic stability

Greater Accuracy in Modal Analysi A promising new framework for analyzing and reducingC. Van Karsen the large, linear, time-invariant dynamic models used toStructural/Kinematics, Warren, MI, Mach. Des., study dynamic stability In power systems is Investigated.55 (13), pp 105-108 (June 9, 1983) 5 figs The framework Is termed Selective Modal Analysis or SMA,5and goes beyond traditional modal analysis methods In

ways that appear crucial to successful practical use of modalKey Words: Modal analysis methods in both on-line and off-lne studies. Comparisons

with existing approaches to the dynamic stability problemAn approach to large structure modal analysis is described are made, and the distinctive features of SMA are broughtwhich evenly excites the entire structure with two shakers out,

71

Im , ' ,, _.-- - . .-- - .L-

83-2299 J.S.W. TaylorDigital Correlation of Spread-Spectrum Signals via Univ. of Surrey, Dept. of Mech. Engrg., Surrey, UK,

Frequency Domain Processing Exptl. Techniques,_7 (6), pp 31-35 (June 1983) 6

J.A. Carretto, Jr. figs, 4 refsSchool of Engrg., Air Force Inst. of Tech., Wright-

Patterson AFB, OH, Rept. No. AFIT/GE/EE/82S-15, Key Words: Dynamic tests, Testing techniques, Digital

70 pp (July 1982) techniques, Time domain method

AD-A 127 434 A time-domain approach for processing of transducer signalsand the implementation of the digital processing techniques

Key Words: Frequency domain method is described, which leads to a very effective system for theenhancement and analysis of dynamic-mechanical test data.

Background information on the theory behind processingspread-spectrum synchronization data in the frequencydomain is presented. The derivation shows that the timedomain pseudo-noise sequence offset is represented in thefrequency domain by frequency modulation on a knowncarrier wave. Following the background development is a 83-2302detailed description of the analog hardware used to imple- An Extension of Paraeval's Theorem and Its Use inment the frequency domain processing techniques. A pro-posed method of digitally extracting the synchronization Calculating Transient Energy in the Frequency Do-

data by Fourier transforming the analog output signal is mainpresented. S.S. Kelkar, L.L. Grigsby, and J. Langsner

Virginia Polytechnic Inst. and State Univ., Blacks-

burg, VA 24601, IEEE Trans., Indus. Electronics,IE-30 (1), pp 42-45 (Feb 1983) 3 figs, 4 refs

83-2300

A Comparison of Field Data Collection Techniques Key Words: Transient response, Frequency domain method

for Use in the Two Surface Method of Sound PowerLevel Determination An analysis is presented which leads to an equation useful

K.R. Baki and RA. Putnam for calculating energy in the frequency domain. The equa-Gilbert/Commonwealth, Jackson, Ml, NOISE-CON tion is seen to be an extension of Parseval's theorem and is

very useful for calculating the energy content of pulses that83, Quieting the Noise Source, Proc. of NatI. Conf. are difficult to treat in the time domain. An algorithm basedon Noise Control Engrg., Massachusetts Inst. Tech., on the equation has been programmed in Fortran.Cambridge, MA, Mar 21-23, 1983, pp 355-360, 8figs, 11 refs

Key Words: Two surface method, Sound power levels, Mea-surement techniques, Noise source identification 83-2303

A method to determine sound power levels in situ in the Dynamic Applications of Piezoelectric Crystals.

presence of high background noise is the subject of a forth- Part III: Experimental Studiescoming ASTM standard. The proposed test procedure, using M.C. D1kmecia form of the two surface method, carefully defines most Istanbul Technical Univ., P.K. 9, Istanbul, Turkey,data collection parameters, but allows for considerable Shock Vib. Dig., 15 (5), pp 11-22 (May 1983) 173flexibility in the size of surveyed areas. This paper compares ref sthe results of two unique approaches to this test variable.Differences in computer generated sound power calculationsfor four high speed manufacturing machines are presented Key Words: Structural members, Piezoelectricity, Waveusing both a gross sweep area, and a smaller, more detailed propagation, Acoustic waves, Reviewsarea methodology.

This paper presents a review of current open literaturepertaining to the dynamic applications of piezoelectriccrystals. Representative theoretical and experimental paperscover waves and vibrations in piezoelectric one-dimensionaland two-dimensional structural elements. New trends of

DigitL Tedhniques for Enhancing and Pfocealan g research are pointed out for future applications of plezo-Dynamic Stei-Andy-i- Data electric crystals.

72

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83-2304 College of Engrg., Nihon Univ., Tokusada, Koriyama,Mechanical Impedance Gauge Based on Measurement Fukushimaken 963, Japan, J. Acoust. Soc. Amer.,of Strainsonan Impacted Rod 73 (6), pp 2187-2192 (June 1983) 7 figs, 2 tables,L. Lagerkvist and K.G. Sundin 13 refsDept. of Mech. Engrg., Univ. of Lulea, S-951 87Lulea, Sweden, J. Sound Vib., 88 (2), pp 225-231 Key Words: Vibration transducers, Ground vibration(May 22, 1983) 5 figs, 7 refs

This paper examines characteristics of frequency responseof a vibration transducer placed on the ground. Optimum

Key Words: Mechanical impedance. Measuring instruments relationships between the base area and the weight of thetransducer for decreasing the effect of ground coupling

An impedance gauge based on measurement of strains at two under all conditions are provided.cross-sections of a slender rod is studied. The gauge rod isin contact with the object at one end while it is impactedat the other end. The impedance is evaluated from the twostrain signals by means of a two-channel FFT-analyzer anda desk-top computer. Gauge prototypes with cylindricaland conical geometries are tested in the frequency range 83-230750 Hz to 5 kHz for cylindrical objects with known theoreti- Effect of Mounting Constraints on the Response ofcal point impedances. Pkelectri Disik

D.B. Bogy and R.T-K. Su

Dept. of Mech. Engrg., Univ. of California, Berkeley,CA 94720, J. Acoust. Soc. Amer., 73 (6), pp 2210-

83-2305 2215 (June 1983) 8 figs, 9 refs

Vibration Analys of Piezoceramic Bimorphic Key Words: Piezoelectric transducersCylindrical Shell in the Two Dimenuional CoordinateSystem by Means of Finite Element Method An experimental investigation was conducted to determineR. Barauskas and L. Limanauskas the effects of different edge conditions and face mountKaunas Politechnical Institute, Kaunas, Lithuanian backing conditions on the electrical response of stronglySSR, Vibrotechnika, 4 (38), pp 93-101 (1981) 6 coupled piezoelectric disks with electroded faces on which

-spatially nenuniform forces are applied _y a pencil leadfigs, 2 tables, 8 refs breaking mechanism. Various mounting schemes were em-(In Russian) ployed to simulate traction-free, simply supported, and

fixed edge conditions. Experiments were alao conducted on aKey Words: Transducers, Piezoceramics, Vibration analysis, commercially available transducer in various stages of dis-Finite element technique mantlement.

", The vibrations of piezoceramic transducer, represented by acylindrical shell, are analyzed. The wall of the shell Is bimor-fic: the exterior layer of it is piezoceramic, polarized inthe direction of the radius; the Interior Is metallic. Becauseof the differences in length and radius of the shell, calcula- 83.2308tions are performed In two dimensions Natural frequencies, Vibration Analy-A of Asymmetric Bimorfic Pieo-modes of vibration, and amplitudes in the radial and tangen- ceramic Transducers by the Finite Element Tech-tieal directions under harmonic electric excitation are deter- niquemined by the finite element method. The dependencies of R. Barauskas and L. Limanauskasnatural frequencies and the amplitudes of vibrations on thei gthlkneof imophc lyerlrepreentd.Kaunas Politechnical Institute, Kaunas, Lithuanian

o SSR, Vibrotechnika, 4 (38), pp 85-92 (1981) 1 fig,

2 tables, 6 refs(In Russian)

83-2306 Key Words: Transducers, Vibration analysis, Plazoceramics,

Grosnd Compiags amd Measrement. Frequency Finite element techniqueRanges of Vibratiom Transducers The finite element method is used for the vibration analysisS. Omata of bimorf Ic asymmetric piezoceramic transducers, consisting

73

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of piezoceramic and metallic layers fixed to one another. This paper describes the development of indirect methodsStiffness and mass matrices of beam type finite element are for the experimental determination of these three param-obtained, taking into account transverse and longitudinal eters.displacements The results of numerical analysis are pre-sented.

83-2309 83-2311Investigation of Continuously Traversing Microphone Noise/Vibration Control by Structural Modification -System for Mode Measurement When and What to ConsiderD.E. Cicon, T.G. Sofrin, and D.C. Mathewc C.I, Holmer and D.T. LilleyPratt and Whitney Aircraft Group, East Hartford, E-A-R Division of Cabot Corp., 7911 Zionsville Rd.,CT, Rept. No. NASA-CR-168040, 135 pp (Nov Indianapolis, IN 46268, NOISE-CON 83, Quieting1982) the Noise Source, Proc. of Nat. Conf. on NoiseN83-19575 Control Engrg., Massachusetts Inst. Tech., Cambridge,

MA, Mar 21-23, 1983, pp 123-132, 5 figs, 13 refsKey WYords: Acoustic measurement, Measurement tech-niques, Modal analysis, Data processing, Ducts, Fans Key Words: Noise reduction, Vibration control, Structural

modification techniquesThe continuously traversing microphone system consists ofa data acquisition and processing method for obtaining the This paper is intended asan introduction to a group of papersmodal coefficients of the discrete, coherent acoustic field dealing with structural modification as a mechanism forin a fan inlet duct. The system would be used in fan rigs or noise control at the source. The source class dealt withfull scale engine installations where present measurement consists of machinery which generates vibration that ismethods, because of the excessive number of microphones transformed at machine surfaces to radiated sound, excludingand long test times required, are not feasible. The purpose sources which generate noise via direct radiation from turbu-of the investigation reported here was to develop a method lent flow.for defining modal structure by means of a continuouslytraversing microphone system and to perform an evaluationof the method, based upon analytical studies and computersimulated tests.

83-2312Application of the Eigenvalue Modification Tech.

83-2310 nique to Nonproportionally Damped StructuresExperinental Determination of Vibration Parameters G. Prater, Jr. and R. SinghRequired in the Statistical Energy Analysis Method The Ohio State Univ., 206 W. 18th Ave., Columbus,B.L. Clarkson and R.J. Pope OH 43210, NOISE-CON 83, Quieting the NoiseInst. of Sound and Vib. Res., Univ. of Southampton, Source, Proc. of Natl. Conf. on Noise Control Engrg.,Southampton, UK, J. Vib. Acoust. Stress Rel. Des, Massachusetts Inst. Tech., Cambridge, MA, Mar 21-Trans. ASME, 105 (3), pp 337-344 (July 1983) 10 23, 1983, pp 133-142, 3 figs, 4 refsfigs, 8 refs

Key Words: Structural modification techniques, DampedKey Words: Dynamic tests, Testing techniques, Modal structuresdensities

A summary of the advantages and disadvantages of a com-In the high frequency range of vibration the statistical energy monly used method for the modification of discrete dy-method provides one of the most convenient ways of esti- namic systems - the elgenvalue modification techniquemating vibration levels in structural components. The dynem- (EMT) - is presented. The EMT uses modal data from theic characteristics of the structure ere described in terms of original system to simplify computation of the naturalthe modal densities, dissipation los factors and coupling frequencies and modes of a modified system. Its use gen-lose factors of the component parts. Theoretical and semi- erally results In significantly lower computation costs, espe-empirical results are available for some typical components. cially for complicated systemsL

74,

i i |4

DYNAMIC TESTS NAL-TR-736, ISSN-0389-4010, 16 pp (1982)(Also see No. 2301) N83-19122

(In Japanese)

83-2313 Key Words: Modal tests, Transfer functionsEffects of Specimen Resonances on Acoustic-Ultra- Applications of the transfer function method to structuralsonic Testing dynamic modal tests are presented. Three test structures;J.H. Williams, Jr., E.B.Kahn, and S.S. Lee i.e., a carbon-fiber reinforced-plastic box beam, an aircraftMassachusetts Inst. of Tech., Cambridge, MA, Rept. structural model, and the Fuji FA-200X are used. The testsNo. NASA-CR-3679, 36 pp (Mar 1983) are conducted by the conventional sine dwell resonanceN83-21373 method as well as the one point excitation transfer func-

tion method.

Key Words: Ultrasonic techniques, Testing techniques, Reso-nant frequencies

The effects of specimen resonances on acoustic ultrasonicnondestructive testing were investigated. Selected resonant 83-2316frequencies and the corresponding normal mode nodal Characterization of Conservatism in Mechanicalpatterns of the aluminum block are measured up to 75.64kHz. Prominent peaks in the pencil lead fracture and sphere Shock Testing of Structuresimpact spectra from the two transducer locations corre- T.J. Bacasponded exactly to resonant frequencies of the block. Ph.D. Thesis, Stanford Univ., 193 pp (1983)

DA8307129

Key Words: Shock tests, Testing techniques

83 -2314 The objective of this research is to characterize field and test8Mo231 TWenvironments in a way that will allow quantitative statementsModal Testing of a Rotating Wind Turbine to be made about the conservatism of a shock test. Alterna-T.G. Carne and A.R. Nord tive characterizations of shock transients are introducedSandia Natl. Lab., Albuquerque, NM, Rept. No. which compensate for the limitations of absolute accelera-SAND-82-0631, 19 pp (Nov 1982) tion shock spectra in representing shock environments. ADE83003630 method of characterizing both field arid laboratory shock

environments is developed which can be used for any typeof shock characterization to account for the variability in the

Key Words: Model tests, Turbines, Wind turbines description of the environments. Conservatism between thefield and laboratory shock environment is then quantified

A testing technique has been developed to measure the in terms of the index of conservatism.modes of vibration of a rotating vertical-axis wind turbine.This technique has been applied to the Sandie two-meterturbine, where the changes In individual modal frequenciesas a function of the rotational speed, have been tracked from0 rpm (perked) to 600 rpm. During rotational testing, thestructural response was measured using a combination of 83-2317strain gages and accelerometers, passing the signals through Piezoslectric Shaker for Simulating Earthquakesslip rings. In addition to calculating the real modes of the J.G. Canclini and J.M. Hendersonparked turbine, the modes of the rotating turbine ware alsodetermined at several rotational speeds. Air Logistics Command, Kelly AFB, TX 78241,

J. Vib. Acoust. Stress Rel. Des., Trans. ASME. 105(1), pp 11-16 (Jan 1983) 11 figs, 7 refs

Key Words: Shakers, Piezoelectric shakers, Earthquake

83-2315 simulation

Some Applieation of the Trander Function Ted. A centrifuge can theoreticlly simulate grevity-induced strsnique to the Modal Survey Teats on earthen structures at a reduced geometric sale throughNational Aerospace Lab., Tokyo, Japan, Rept. No. centrifuge loading. These emling laws show the usefulnessof

73

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the centrifuge to test large structures of a size that cannot be 83-2320tested practically in any other fashion. Seven possible shaker Acoustic-Eminsion Linear-Puse Holographydesigns were considered. The paper presents a description of H.D. Collins, D.K. Lemon, and L.J. Bussethe piezoelectric shaker chosen and its development for a 5-g Battelle Pacific Northwest Labs., Richland, WA,ton capacity centrifuge. Rept. No. PNL-SA-10523, CONF-820765-1, 16 pp

(June 1982) (Intl. Symp. on Acoustical Imaging,London, UK, July 19, 1982)DE83003476

83-2318 Key Words: Diagnostic techniques, Nondestructive tests,Crack propagation, Acoustic emission, Holographic tech-

Vibration and Aeroelastic Facilty niquesP.G. BoldsAir Force Wright Aeronautical Labs., Wright-Patter- This paper describes acoustic emission linear pulse holog-

son AFB, OH, Rept. No. AFWAL-TR-82-3054, 100 raphy which combines the advantages of linear imaging andpp (Dec 1982) acoustic emission into a single NDE inspection system. This

unique system produces a chronological linear holographic

AD-A 126 317 image of a flaw by utilizing the acoustic energy emittedduring crack growth.

Key Words: Vibration tests, Test facilities

The vibration and aeroelastic facility of the Air Force WrightAeronautical Laboratories is used for recording and analyzingdynamics data. New instrumentation systems have made 83-2321possible a significant increase in the quantity of measure-ments which can be acquired to define the dynamics environ-ment in various aircraft, missile, and ground support equip- T. Chander and S. Biswasment. To reduce the large quantities of data to a usable form, Bharat Heavy Electricals Ltd., Hyderabad - 500 593,processing techniques based upon the use of spectrum India, Tribology Intl., 16 (3), pp 141-146 (Juneanalyzers and minicomputers are employed. These techniques 1983) 15 figs, 3 tables, 8 refsare described and methods are Illustrated fc- presentingI statistical quantities defining the spectral composition ofdynamics environments. Key Words: Couplings, Flexible couplings. Gears, Diagnostic

techniques

A number of failures which occurred in the gear couplingtransmitting the torque from a steam turbine (rotating at7500 r/min) to a 1.5 MW generator through a 1:5 reduction

DIAGNOSTICS gear box are studied.

-I

83-2319 83-2322

Diagnos of Fracture Damage in Simple Structures: Research to Develop and Evaluate Advanced EddyA Modal Method Current Sensors for Detecting Small Flaws in MetallicF.J. Ju, M. Akgun, T.L. Paez, and E.T. Wong Aerospace Components

Bureau of Engrg. Res., Univ. of New Mexico, Albu- J.M. Prince and B.A. Auld

querque, NM, Rept. No. CE-62(82)AFOSR-993-1, Battelle Pacific Northwest Labs., Richland, WA,AFOSR-TR-83-0049, 58 pp (Oct 1982) Rept. No. AFWAL-TR-82-4155, 101 pp (Dec 1982)AD-A125 714 AD-A125 873

Key Words: Diagnostic techniques, Crack detection, Modal Key Words: Diagnostic Instrumentation, Eddy currentanalysis probes, Ferromagnetic resonance

A method to locate fracture damage in a structure and to The purpose of this program wee to develop a reproducible,estimate the intensity of the damage is investigated, highly sensitive novel eddy current probe applying the

76

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technique of ferromagnetic resonance (FMR). The method 83-2325developed must be suited to inspect test objects where Balancing of Linkages -an Updateaccess may be limited; for example, bolt holes of turbine G.G. Lowen, F.R. Tepper, and R.S. Berkofengine disks. This program studied the FMR probe in bothIts passive and active modes. Dept. of Mech. Engrg., City College of the City Uni-

versity of New York, NY 10031, Mech. Mach. The-ory, 18 (3), pp 213-220 (1983) 158 refs

BALANCING Key Words: Dynamic balancing, Balancing techniques, Link-

(Also see No. 2326) ages

Improved balancing techniques have been required morefrequently as machine performance specifications have

83-2323 become more demanding. Following this trend, many moreBlancing of Flexible Rotors by the Complex Model technical papers on the dynamic balancing of mechanisms

Method have been published in the past few yearL This recent litera-ture on the force and moment balancing of linkages is sur-

S. Saito and T. Azuma veyed.Res. Inst., Ishikawajima-Harima Heavy IndustriesCo., Ltd., 3-1-15, Toyosu, Koto-ku, Tokyo, Japan,J. Vib. Acoust. Stress Rel. Des., Trans. ASME, 105(1), pp 94-99 (Jan 1983) 10 figs, 4 tables, 22 refs MONITORING

Key Words: Balancing techniques, Flexible rotors, Rotors,Fluid-film bearings 83-2326

Vibration and Balance Problems in Fossil Plants:A new calculation method of the modal unbalance response Industry Case Historiesfor general flexible rotors in fluid film bearings is developed N.L. Baxterby introducing the concept of modal exciting force vector Public Service Co. of Indiana, Inc., Plainfield, IN,into the usuel complex model method. The physical meaningof the damping ratio at a critical speed isdiscussed. Applica- Rept. No. EPRI-CS-2725, 156 pp (Nov 1982)tion of this method, correction weights determined in only DE83900743one trial operation, is reported, and positions to measurevibration and to correct unbalance weight are discussed on Key Words: Monitoring techniques, Balancing techniques,the basis of the right eigenvector and the exciting factor Fossil power plants, Power plants (facilities)mode, respectively.

The purpose of this report is to demonstrate some practicaluses of vibration analysis through the presentation of actualfield case histories. The case histories contained in thereport include turbines, generators, fans, pump and electric

83-2324 motors common to the utility industry. Each case historyA Comnputatiosnal Tedhnique for Optinizing Cofec- Is divided Into six sections: definition of the problem, symp-

toms of the problem, test data and observations, correctivetion Weihts and Axial Location of Balance Planes actions taken, final results, conclusions end recommenda-of Rotating Shafts tions.W.D. Pilkey, J. Bailey, and P.D. SmithUniv. of Virginia, Charlottesville, VA 22901, J. Vib.Acoust. Stress Rel. Des., Trans. ASME, 105 (1), pp90-93 (Jan 1983) 2 figs, 2 tables. 4 refs ANALYSIS AND DESIGNKey Words: Balancing techniques, Shafts, Influence coeffi-cent method

An Iterative procedure is presented for the balancing of a ANALYTICAL METHODSflexible rotor. In addition to determining optimal correctionweights, the number and axial positions of the balance planesre optimized. A linear programming solution Is employed

using a linearized approximation of the axial variation of the 83-2327influence coo" Icients. The Equivalence of Tie Integration Method for

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'i,* .a " "

Dynamic Systems (Zur Aquivalenz der Zeitintega. A frequency domain approach for reducing linear, time-tionawerfahren fGr dynamsche Syateme) invariant systems is presented which produces stable approxi-

M. Weber mation of stable systems. The method is based upon theSchwarz canonical form and is shown to have a continued-Akad. of Sci., German Dem. Rep., DDR-1 199 Berlin, fraction representation. A link between this method and the

Z. angew. Math. Mech., 63 (3), pp 151-160 (1983) popular Routh approximation is also given.1 table, 12 refs(In German)

Key Words: Dynamic systems, Time integration method

This paper deals with the comparison of the most important 83-2330algorithms for the direct time integration of dynamic sys- Characterization of Frequency Stability: Bia Due totems. The algorithms are divided in several classes with Charactariztion of Teq nteral Besre torespect to the used deduction methods. the Juxtaposition of Time-Interval Measurements

P. LesageLaboratoire de I'Horloge Atomique, Equipe deRecherche due CNRS, Associee a% I'Universite Paris-Sud, 91405, Orsay, France, IEEE Trans., Instrum.Meas., IM-32 (1), pp 204-207 (Mar 1983) 5 figs,1 table, 7 refs

83-2328Dyuamic Analysis of Mechanisms via Vector Net- Key Words: Frequency analysiswosk Model The characterization of frequency stability is usually a-K. Sinqhal and H.K. Kesavan chieved by means of numerically processed time-intervalDept. of Systems Design, Univ. of Waterloo, Water- measurements. In the present paper, the bias occurring in theloo, Ontario, Canada, Mech. Mach. Theory, 18 (3), frequency stability measure when successive data with thepp 175-180 (1983) 3 figs, 4 refs same mean durations are added in order to get different sets

of samples with various mean durations is studied. The effect

of a dead time between the data involved in the consideredKey Words: Vector network model, Mechanisms, Computer- algorithm is pointed out. An experimental analysis is pre-aided techniques sented which checks the theoretical results for several noise

processes in different experimental conditions.The vector network model has already bean defined both forproblems in dynamics as well as for kinematics. For theletter, the model was developed for a sequential determina-tion of position, velocity and acceleration variables associ-ated with mechanisms. This paper deals with the next phase

of kinematic analysis; namely, the dynamic analysis ofmechanisms. 83-2331

Dynamic Analysis of Large Scale Inertia-VariantFlexible SytemsA.A,-E. ShabanaPh.D. Thesis, Univ. of Iowa, 211 pp (1982)

83-2329 DA8310084

Frequensry-Domap Reduction of Linear Systems Key Words: Transient response, Equations of motion, Vari.Usng Sehwarz Approxisation able material propertiesT.N. Lucas and A.M. DavidsonDept. of Mathematics and Computer Studies, Dundee A method employing a variable number of degrees of free-College of Tech., Bell St., Dundee, UK, Intl. J. Con- dom is developed for transient dynamic analysis of mechani-trol, .Z (5), pp 1167-1178 (May 1983) 2 figs, 4 cal systems consisting of constrained rigid and flexibiebodlestables, 12 refs with large angular rotations. Gross displacement of elastic

bodies is represented by superposition of small elastic dis-

placements on large displacement of body reference framea.Key Words: Approximation methods, Frequency domain For each elastic body two sets of generalized coordinates aremethod, Linear systems employed.

78

I Mas

83-2332 George C. Marshall Space Flight Ctr., NASA, Hunts-Alternative Bond Graph Causal Patterns and Equation ville, AL, Rept. No. NASA-TM-82512, 31 pp (FebFormulations for Dynamic Systems 1983)D. Karnopp N83-20281Univ. of California, Davis, CA 95616, J. Dynam.Syst., Meas. Control, Trans. ASME, 105 (5), pp 58- Key Words: Mass coefficients, Damping coefficients, Stiff-63 (June 1983) 6 figs, 7 refs ness coefficients

The augmentation of structural characteristics, mass, damp-Key Words: Bond graph technique ing, and stiffness through the use of control theory in lieu

of structural redesign or augmentation is reported. TheGiven mathematical models of components of a system, the standard single-degree-of-freedom system was followed by aequations for the system can be formulated in a number of treatment of the same system using control augmentation.distinct ways. Bond graphs provide a convenient explicit way The system was extended to elastic structures using singleto study the interactions among component models and the and multi-sensor approaches and concludes with a briefsystem equation formulations which follow from the various discussion of potential application to large orbiting spaceways in which input-output causality can be assigned. Three structures.means of causality assignment are compared: an all-integralmethod, an all derivative method, and a Lagrange-equationprocedure. Some interesting differences among the pro-cedures occur when fields (dependent state variables) ornonlinear junction structures (geometric nonlinearities) are 83-2335present in the system model. Generalized Rayleigh-Ritz Method for Structural

Dynamics Problems in Conjunction with Finite Ele-mentsJ.J. Wu

83-2333 Large Caliber Weapon Systems Lab., Army Arma-Accuracy Criteria for Evaluating Supersonic Missile ment Res. and Dev. Command, Watervliet, NY,AccrayCitei n fo rEluatin Sup Missile Rept. No. ARLCB-TS-83006, 23 pp (Feb 1983)Aerodynamic Coeficent AD-A 126 481R.J. Krieger and J.E. WilliamsMcDonnell Douglas Astronautics Co., St. Louis, MO,J. Spacecraft Rockets, 20 (4), pp 323-330 (July/Aug Key Words: Rayleigh-Ritz method, Flnite element technique1983) 6 figs, 10 tables, 11 refs A solution formulation of generalized Rayleigh-Ritz method

is described and applied to two Initial and boundary valueKey Words: Aerodynamic stability, Prediction techniques, problems of stress waves and structural dynamics in con-Error analysis junction with finite element discretization. Excellent numeri-

cal results have been obtained for wave equations associated

Aerodynamic prediction methods are traditionally compared with lateral and longitudinal vibrations and with strongwith wind-tunnel test data. However, the assessment of discontinuities.accuracy is left to an arbitrary interpretation. An accuracycriterion has been developed that defines the required predic-tion accuracy in terms of allowable errors in missile perfor-mance and missile design parameters. Equations have beenselected that relate these parameters to the aerodynamic 83-2336drag, stability, and control coefficients. These equations Rayleigh's Contributions to Modem Vibrationare differentiated with respect to the aerodynamic coeffi- Analysiscients and simplif led when possible. GB. Warburton

' Dept. of Mech. Engrg., Univ. of Nottingham, Notting-ham NG7 2RD, J. Sound Vib., 88 (2), pp 163-173(May 22, 1983) 1 fig, 49 refs

83-2334 Key Words: Vibration analysis, Rayleigh methodpreliminary Look at Control Augmented! DynaiResponse of Structures Although Rayleigh performed his work on vibrations approx-R.S. Ryan and R.E. Jewell Imately one hundred years ago, his contributions with their

79 - "

-A-

emphasis on energy principles, approximate methods of 83-2339solution and use of physical insight to assess problems lead A Study on Parameter Determination Method ofdirectly to some of the most powerful methods of vibration Large-Scale and Complex Dynamic System# withanalysis which are in use today. His contributions end theirrelationship to modern analytical methods are outlined and Judgment (No. 2) Applicationsillustrated by simple examples. 0. Furukawa, H, Hiroyasu, and S. l ida

Kubota Ltd., Sakai, Japan, J. Dynam. Syst., Meas.Control, Trans ASME, 105 (5), pp 70-76 (June1983) 11 figs, 1 table, 14 refs

PARAMETER IDENTIFICATION Key Words: Parameter identification technique, Judgment(Also see No. 2198) functions, Diesel engines

This paper deals with the parameter satisfaction problems

of a gas exchanging system which are important from the

83-2337 standpoint of quality design. Report No. 1 proposed a meth-

Parameter Identification and Control of Distributed- od to solve the parameter satisfaction problems of suchsystems. In this paper, the method is applied and a param-

Parameter Systems eter improvement system which can improve many param-H. Baruh eters efficiently without enormous calculations of partialPh.D. Thesis, Virginia Polytechnic Inst. and State derivatives is constructed.Univ., 125 pp (1981)DA8210374

Key Words: Parameter identification technique, Continuousparameter method 83-2340

Mode Identification of Bilinear SystemsTwo methods, one for the identification and one for thecontrol implementation of distributed-parameter systems, C.B. Smith, B. Kuszta, and J.E. Baileyare presented. The methods are designed to identify and Dept. of Chemical Engrg., Univ. of Houston, Hous-control the actual distributed system, without resorting to ton, TX 77004, Intl. J. Control, 37 (5), pp 943-957discretization. (May 1983) 5 figs, 7 refs

Key Words: Parameter identification technique

A method is presented for the identification of the eigen-values of systems characterized by bilinear differential equa-

83-2338 tion models, The identification procedure is based on theA Study on Parameter Determination Method of existence of a zero harmonic, or DC shift, in the output of

Large-Scale and Complex Dynamic Systems with nonlinear systems perturbed by a periodic Input.

Judgment Funetions (No. 1) -Theory0. Furukawa, H. Ikeshoji, and S. lidaKubota Ltd., Sakai, Japan, J. Dynam. Syst., Meas.Control, Trans. ASME, 105 (5), pp 64-69 (June1983) 5 figs, 19 refs 83-2341

Parameter Estinmation for the Fast and Slow Sub-

Key Words: Parameter identification technique, Judgment systems of a Procese Operating in Coupled Singularlyfunctions Perturbed Form

M.J. CookIn the design of large-scale and complex mechanical systems, Ph.D. Thesis, Michigan State Univ., 144 pp (1982)

* determination of design parameters is a very difficult prob- DA8308916lam. This study deals with parameter setisfaction problems

of larg-soele, complex, and dynamic systems with judgmentfunctions. In order to solve thes problems, a new method is Key Words: Parameter identification techniquesproposed which sequentially exchanges the original mathe-

: mtkcel model to an analyzalble approximte model by mens The Input and output of a cleterminitic singularly perturbed

of the idetWification method. system, operating In coupled form, are observed over a finite

-so

I II !a_ _

time-interval. The problem under consideration is to deter- This report provides an updated user's manual for DYNA3D,mine the system parameters of the decoupled subsystems an explicit three-dimensional finite-element code for ana-from these measurements. The nature and formulation of lyzing the large-deformation dynamic response of inelastic-* s singularly perturbed system are examined along with solids. DYNA3D contains fifteen material models and ninethe fundamentals of systems identification. A finite time- equations of state to cover a wide range of material behavior.interval identification method is investigated which utilizesa filter to annihilate the initial condition response, andmodels disturbances as solutions to a homogeneous differen-tial equation. The adaptation of this method is applied to thesingularly perturbed problem, and a unique procedure for 83-2344its implementation is presented via a heuristic study of Computer Programs for Estimation of the Flutterlinear time invariant systems and Divergence Boundaries from Random Responses

at a Subcritical RangeY. Ando and Y. MatsuzakiNatl. Aerospace Lab., Tokyo, Japan, Rept. No. NAL-

DESIGN TECHNIQUES TR-737T, ISSN-0389-4010, 66 pp (Sept 1982)N83-19498

83.234,2 Key Words: Flutter, Random response, Aeroelasticity

Minimum Cost Design for Noise Insulation in Build- A set of computer programs for a method of estimation of

ing Construction the vibration characteristics and boundaries for flutter and

F,F, Rudder and S.F. Weber divergence of an aeroelastic system subjected to stationaryU.S. Dept. of Commerce, Nat]. Bureau of Standards, random noises is described. The programs listed are thoseWashington, DC 20234, Noise Control Engrg., ( (3), for the calculations of the auto-covariance function of a

time series and Jury's stability parameters of the characteris-pp 104-121 (May/June 1983) 9 figs, 3 tables, 24 refs tic equations of fourth and eight orders, and those for the

estimation of the stability boundary, frequency and dampingKey Words: Design techniques, Noise reduction ratio of the system.

A method is described for estimating the construction costof building components designed to achieve a specified levelof noise insulation. The method also determines the noiseinsulation value of each component of a multi-component 83-2345well, such that the wall achieves a design level of noise GEMINI - An Efficient Computer Program for Threeinsulation at the minimum construction cost. Curves ofminimum construction cost as a function of design noise Dimensonal Linear Static and Seimic Structuralinsulation are easily generated using the method. Analysis I

; RC. Murray

Ph.D. Thesis, Univ. of California, Davis, CA, 351 pp(1982)~DA8311926

COMPUTER PROGRAMS(Also see No. 2190, 2193)

Key Words: Computer programs, Seismic analysis, Structuralmembers, Finite element technique, Dynamic structural

83-2343 analysis

GEMINI Is a computer program for the calculation of staticDYNA3D User's Manual (Nonlinear Dyn mi An ly- and dynamic response of linear elastic structures by thess of Soid s in Three Dimemiona) finite element method. Requests for extended capability,J.O. Hallquist advances in element technology, and major algorithmicLawrence Livermore Nati. Lab., CA, Rept. No. improvements in solution methodology have lead to the

UCID-19592, 109 pp (Nov 1982) need, creation, and development of this program. GEMINI

DE83004058 is written in standard FORTRAN with a modular formatto allow new elements to be inserted as well as allowingequation solvers, elgenvalue routines, and model analysis

Key Words: Computer programs, Nonlinear theorie. Three techniques to be implemented and evaluated. GEMINI ildimensional problems, Finite element technique compatible with the CDC7600 and the CRAY-1 computers

S*-4-

83-2346 Ph.D. Thesis, Univ. of Houston, 157 pp (1982)MIDSY and ADAMS Computer Programs for Design DA8310662Orientated Modeling and Identification of Linear andNonlinear Multibody Systems (Prograsmnsysteme Key Words: Computer programs, Sound pressures, VibratingMIDSY and ADAMS zum strukturorientierten structuresModeflieren und Identifizieren von linearen und

This thesis describes the development and applications of anichtlinearen Mehrkorpersystemen) FORTRAN nrogram for obtaining an estimate of the acous-Konstruktion, 35(6), p 246 (June 1983) 2 figs tic pressure on a closed surface vibrating steadily at a single(In German) frequency. The algorithm is based on a boundary integral

equation for the pressure on the surface. The inputs required

Key Words: Computer programs, Design techniques, Motor by the program are the surface geometry and motion.

vehicles

The capabilities of MIDSY and ADAMS computer programsare summarized. They enable a designer, even without athorough knowledge of vibration theory, to model, simulate,and optimize the dynamic behavior of his design (multibodysystem). The results of the simulation are a time- or frequen- 83-2349cy-dependent (FFT) representation of deflection, velocity User's Guide to Producing Coherency-Based Equiva-and acceleration. They also show the excitation and deforma-tion of elastic transfer elements of all the components of lents for Transient-Stability Studies

the system. The programs are applicable in automotive J.V. Mitscheindustry. Consumers Power Co., Jackson, MI, Rept. No. EPRI-

E L-2778-CCM, 24u pp (Dec 1982)DE83901140

Key Words: Computer programs, Dynar,>. .:ability83-2347

This report is the user's guide for a computer programFLUTTER: A Finite Element Program for Aerody- called DYNE03. This program reduces a large-scale systemnamic Instability Analysis of General Shells of Revo- model to a small dynamic equivalent model for use in tran-lution with Thermal Prestress sient stability studies. It ;s dimensioned large enough toD.J. Fallon and E.A. Thornton model the entire eastern US interconnected system. Classical

Old Dominion Univ., Norfolk, VA, Rept. No. NASA- transient stability models are used.

CR-170013, 18 pp (Mar 1983)

N83-19756 IKey Words: Computer programs, Flutter, Shells of revolu-tion

83-2350Documentation for the computer program FLUTTER is New Numerical Method for the Transient Gas-Dy-presented. The theory of aerodynamic instability withthermal prestress is discussed. Theoretical aspects of the namic Code EVENTfinite element matrices required in the aerodynamic insta- P.K. Tangbility analysis are also discussed. General organization of Los Alamos Natl. Lab., NM, Rept. No. LA-9594-MS,the computer program is explained, and instructions are 21 pp (Dec 1982)presented for the execution of the program. DE83007120

Key Words: Computer programs, Numerical analysis

A new numerical method to solve a system of algebraic83-2348 equations for severe gas-dynamic transient problems isComputation of Acoustic Surface Pressure Using described. This technique involves the simultaneous consid-

eration of both mass and energy balance at each nodal point,Boundary Integral Equations which should improve the convergence. A sample calculation KH.R. Hall is included.

82

4 --.

structural equations are integrated simultaneously to obtainthe time dependent aeroelastic response of the wing.

BIBLIOGRAPHIESCRITERIA, STANDARDS, AND (Also see Nos. 2161,2256)

SPECIFICATIONS

83-2353Earthquake Engineering: Buildings, Bridges, Dams,

83-2351 and Related Structures. September 1980 -FebruaryEconomic Effects of Noise Abatement Regulations 1983 (Citations from the NTIS Data Base)on the Helicopter Industry NTIS, Springfield, VA, 316 pp (Apr 1983)A.N. Conner PB83-805184Naval Postgraduate School, Monterey, CA, 66 pp(Dec 1982) Key Words: Bibliographies, Seismic design, Bridges, Build-

AD-A127 331 ings, Dams

Seismic phenomena relative to buildings, bridges, dams, andother structures are investigated. Damage assessment is made

The economic effects of noise abatement regulations on the and design inadequacies are revealed. Suggestions for struc-

helicopter industry are discussed. Increased manufacturing tural improvements for dynamic response are presented.Abstracts on site selection and earthquake-proofing for

and operating costs from noise abatement regulations onSikorsky's S-76 helicopter are estimated. The effects on

consumer utilization are also discussed. An appendix com-pares independent research studies that used weight esti-mating relationships and cost estimating relationships toestimate manufacturing costs of the helicopter by subsys-tem.

83-2354Vibration in Turbomachinery: A Bibliography ofResearch Reports (1966- 1981)P.M.E. Percival

83-2352 Dept. of Engrg., Cambridge Univ., UK, Rept. No.

Numerical Simulation of Tranonic Flutter of a CUED/A-TURBO/TR-109-1982, 26 pp (Apr 1982)

Supercritical Wing PB83-187369

K. Isogai and K. SuetsuguNational Aerospace Lab., Tokyo, Japan, Rept. No. Key Words: Turbomachinery, Aerodynamic loads, Vibration

NAL-TR-726T, ISSN-0389-4010, 34 pp (Aug 1982) response, BibliographiesN83-18743 This report is mainly concerned with papers which have been

written in English or which are available in translationsKey Words: Aircraft wings, Flutter, Numerical methods, The first part of the bibliography is an alphabetical list ofSimulation authors, with a separat, list of Russian authors. This is

followed by a list of authors and titles of papers togetherThe time marching three-dimensional unsteady transonic with specific references to relevant pages. The title refersfull potential code USTF3 is applied to the prediction of the generally to vibration in turbomachinery, but the reportflutter boundary of a supercritical wing for which reliable Is restricted to references to vibration arising from aerody-experimental date exist. The governing flow equation and the namic effects.

W 8

83

4

AUTHOR INDEX

Abdel Rahman, M.A ....... 2191 Brower, M .............. 2138 D(kmeci, M.C ........... 2303Abel, I................ 2266 Brown, J.D ............. 2229 Drake, M.L ............. 2283Akgun, M.............. 2319 Brown, K.C ............. 2216 Dubowsky, S ............ 2251Akkas, N ........... 2206,2207 Busse, L.J .............. 2320 Durkin, M .............. 2150Ando, Y ............... 2344 Canclini, J.G ............ 2317 Durrani, A.J ............. 2199Aristizabal-Ochoa, J.D ...... 2234 Cann, R.G .............. 2250 Ebbeson, G.R ........... 2244

Arnold, R.............. 2262 Capps, R.N ............. 2288 Eder, J ................ 2208Atassi, H ............... 2270 Carlucci, L.N ............ 2229 Edwards, J.W ........ 2160,2278

Auld, B.A .............. 2322 Carne, T.G ............. 2314 Ehsani, M.R ............. 2201Azuma, T .............. 2323 Carretto,J.A.,Jr ......... 2299 EI-Raheb, M ............ 2232Baca, T.J ............... 2316 Carta, F.O .............. 2162 Elwany, M.H.S ........... 2210Bailey, J ............... 2324 Ceen, R.V .............. 2255 Errichello. R ............ 2273Bailey, J.E .............. 2340 Chander, T ............. 2321 Ezcll, J ................ 2239Baki, K.R .............. 2300 Chao,H.C .............. 2196 Fafitis, A . ............. 2262Ballato, A .............. 2267 Chapman, N.R ........... 2244 Fallon, D.J ............. 2347Balombin, J.R ........... 2247 Chari, M.V.K ............ 2237 Farley, G.L ............. 2179Bandstra, J.P ............ 2284 Chartoff, R.P ............ 2283 Fatemi, B .............. 2272Barauskas, R ........ 2305, 2308 Chattopadhyay, A ........ 2294 France, E.R ............. 2277Barber, J.R ............. 2289 Chen, C . .............. 2218 Fu, L.S ................ 2292Barker, D.B ............. 2290 Chen, S.S .............. 2213 Furukawa, 0 ........ 2338,2339Barr, A.D.S ......... 2210, 2275 Cheng, H.S ............. 2196 Futakawa, A ............ 2148Baruh, H ............... 2337 Cicon, D.E ............. 2309 Ganesan, N ............. 2187

Bass, H.E ............... 2239 Clarkson, B.L ............ 2310 Gazanhes, C ............. 2265Baxter, M .............. 2196 Cole, V ................ 2252 Gill, S.J . .............. 2286Baxter, N.L ............. 2326 Collins, H.D ............. 2320 Gilyard, G.B ............ 2160Beards, C.F ............. 2200 Coltman,J.W ............ 2165 Goodno, B.J ............ 2151Benade, A.H............ 2233 Comninou, M ............ 2289 Gordaninejad, F .......... 2209 IBerg, G.J ............... 2142 Conner, A.N ............. 2351 Gottenberg, W.G ......... 2181

Berkery, J.F ............ 2237 Cook, M.J .............. 2341 Grigsby, L.L ............ 2302Berkof, R.S ............. 2325 Cornell, R.W ............ 2194 Gubser, J.L ............. 2269Berry, V.L .............. 2166 Craig, J.I .............. 2151 Guntur, R.R ............ 2175Bert, C.W .............. 2209 Crocker, M.J ........ 2143, 2252 Gupta, P.K ............. 2190Bierman, R.L ............ 2178 Cronkhite, J.D ........... 2166 Haas, T.J ............... 2166

Biswas, S ............... 2321 Crooker, T.W ............ 2286 Hall, H.R .............. 2348Bland, S.R .............. 2278 Cunningnam, R .......... 2281 Hallquist, J.0 ............ 2343Blodgett, R.E ............ 2205 Cuntze, R .............. 2208 Harris, W.L ............. 2253

Bogy, D.B .............. 2307 D'Archangelo, J.M ........ 2258 Healy, G.J .............. 2168Bojarski, N.N ............ 2293 Davidson, A.M ........... 2329 Hemsch, M.J ............ 2171

Bolds, P.G .............. 2318 Davies, M.R.D ........... 2184 Henderson,J.M .......... 2317Boley, W.E ............. 2277 Decuyper, M ............ 2182 Herault, J.P ............. 2265Bolukbasi, A.O ........... 2165 deHoop, A.T ............ 2254 Hiroyasu, H ............. 2339Brehm, L.W ............. 2248 Dendrou, t.D ............ 2149 Ho, New-Jin ............ 2202

Brennecke, W ............ 2172 Dhagat, S.K ............. 2204 Hollinger, F ............. 2154Briley, R.P .............. 2269 Dickey, J.W ............. 2258 Holm, R.G ............. 2139Bringi, V.N ............. 2238 Dimsdale, J.S ............ 2198 Holmer, C.I ............. 2311

84

lida, S ............ 2338,2339 Lee, M.-S .............. 2173 Nishimura, T ............ 2221Ikeshoji, H .... ......... 2338 Lee, S.S ............... 2313 Nixon, D.A ............. 2258Imai, Y ................ 2287 Leissa, A ............... 2235 Nord,A.R .............. 2314Inoue, J ............... 2264 Lemon, D.K ............ 2320 Olhoff, N .............. 2215Irie, T ................. 2219 Lesage, P ............... 2330 Omata, S ............... 2306

Ishida, F ............... 2148 Lilley, D.T . ............ 2311 O 'Neill, H.J ............. 2167Isogai, K ............... 2352 Limanauskas, L ...... 2305, 2308 Ookuma, M ............. 2212lyengar, T.K.V ........... 2271 Lips, K.W.............. 2170 Ort, R.E ............... 2174Jabali, H.H ............. 2153 Lo, K.H ............... 2181 Oyibo, G.A ............. 2217Jean, M................ 2280 Loeffler, .J ............. 2247 Pace, N.G....... ....... 2255Jewell, R.E ............. 2334 Lowen, G.G ............. 2325 Paez,T.L .............. 2319Jha, C.S ............... 2142 Lucas, T.N ............. 2329 Paidoussis, M.P........... 2214Jolly, A ............... 2176 Luzzato, E ............. 2280 Palazzolo, A.B .......... 2141Jones, B.G .............. 2276 Lyon, R.H .............. 2268 Palsson, H .............. 2151Jones, R .............. 2216 Ma, Y ................. 2238 Parkin, M.W............ 2277Ju, F.D................ 2319 Maattanen, M ............ 2156 Payne, S.G ............. 2241

Kachadourian, G......... 2158 MacBain, J.C ............ 2225 Percival, P.M.E ........... 2354Kahn, E.B .............. 2313 Mahata, N.P ............. 2294 Perez-Arriaga, I.J......... 2298Kalyanasundaram, N ....... 2245 Majumdar, A.K .......... 2205 Perry, G.S .............. 2166

Kang, B.-S.J ............. 2290 Mamed-Zade, O.A ......... 2285 Pery,A ................ 2145Karim-Panahi, K .......... 2295 Martin, H.R ............. 2144 Peters, D.A ............. 2169Karnopp, 0 ............. 2332 Martinez, R ............. 2253 Pilk~y, W.D ......... 2141,2324Kasuba, R .............. 2195 Masri, S.F .............. 2203 Piranda, J .............. 2227

Kato, R ............... 2228 Matake, T .............. 2287 Plaut, R.H .............. 2215Keefe, D.H ............. 2233 Mathews, D.C ........... 2309 Plunkett, A.W ........... 2152Kelkar, S.S ............. 2302 Matsuzaki, Y ............ 2344 Poon, S.Y .............. 2189Kerimov, S.G ............ 2285 Matsuzaki, Y ............ 2282 Pope, R.J .............. 2310Kesavan, H.K ............ 2328 McCann, E.O ............ 2139 Popov, E.P ............. 2197Ko, T ................. 2169 McClure, W.B ............ 2259 Poppe, W .............. 2291Kobayashi, A.S ........... 2290 Mengi, Y ........... 2206, 2207 Pototzky, A.S ........... 2266Kobayashi, Y ............ 2219 Meyyappa, M ............ 2151 Prabhu, J.J ............. 2187Koch, R.A .............. 2241 Miller, R.H ............. 2136 Prater, G., Jr ............ 2312Koch, W ............ .. 2222 M iller, R.K ............. 2272 Price, S.J ............... 2214 IKorn,A.E .............. 2169 Minnich, S.H ............ 2237 Prince, J.M ............. 2322

Koroyannakis, D ......... 2230 Mitsche, J.V ............ 2349 Putnam, R.A ............ 2300Kotb, M ............... 2157 Miyaura, S .............. 2264 Rahimi, A .............. 2224Krieger, R.J ............. 2333 Miyazaki, N.............2228 Raju, P.K .............. 2252

Kumar, V .............. 2188 Modi, V.J .............. 2170 Ramulu, M ............. 2290Kuo, J.S-H ............. 2155 Mokhtar, M.O.A .......... 2191 Rao, A.R .............. 2226Kurihara, R ............. 2228 Morris, T.L ............. 2251 Rao, J.S ........... 2135,2185Kusic, G. L .............. 2236 Mura, T ............... 2292 Raspet, R .............. 2239Kuszta, B .............. 2340 Muramatsu, N ........... 2148 Rau, G ................ 2147Laananen, D.H ........... 2165 Murray, R.C ............ 2345 Reiff, D.D .............. 2203Lagerkvist, L ............ 2304 Murthy, C.S.C ........... 2226 Remmers, H ............ 2172Lakshmana Rao, S.K....... 2271 Murthy, S.S ............. 2142 Ricketts, R.H ............ 2164Landsberger, B.J .......... 2163 Nagamatsu,A ........... 2212 Ross, D.F .............. 2143Lang, G.F .............. 2297 Nagaya, K .............. 2220 Rossow, M.P ............ 2169

Langenbrunner, L.E ....... 2139 Nayfeh,A.H ............ 2274 Rudder, F.F ............ 2342Langsner, J ............. 2302 Neupert, B ............. 2193 Rutherford, S.R .......... 2241 '6Leandre, J .............. 2265 Newsom, J.R ............ 2266 Ryan, R.S .............. 2334

Lecoanet,H ............. 2227 Nielsen, J.N ............. 2171 Safar, Z.S .......... 2191,2192

85i

St. Hilaire, A.O .......... 2162 Soom, A ............... 2173 Wang, B.P.............. 2141Saito, K .......... .... 2228 Sparks, C.R ............. 2140 Warburton, G.B .......... 2336Saito, S... ............ 2323 Stange, W.A ............. 2225 Wardle, F.P ............. 2189Salon, S.J .............. 2236 Stott, S.J .............. 2203 W atson, J.J ............. 2164Salyer, 1.0 .............. 2283 Su, R.T-K .............. 2307 W att, D ................ 2275Samaha, M ............. 2157 Suaris, W ............... 2263 Weaver, D.S ......... 2230, 2231Sandford, M.C ........... 2164 Suetsugu, K ............. 2352 Weber, M .............. 2327Sankar, S .......... 2175,2177 Sundin, K.G ............ 2304 Weber, S.F .............. 2342Sankar, T.S ............. 2157 Szemplinska-Stupnicka, W. .. 2279 Westervelt, W.W .......... 2194Schaffert, E ............. 2249 Takagi, Y .............. 2221 Whitehead, D.S .......... 2184Schmidt, D.K ............ 2159 Takase, T .............. 2287 Whitman, A.M ........... 2183Schweppe, F.C ........... 2298 Takeya, K .............. 2148 Wight, J.K .......... 2199, 2201Scott, D.J .............. 2236 Tan, R.Y ............... 2211 Wilcox,C.H ............. 2242Seidel, D.A ............. 2164 Tang, P.K .............. 2350 Williams, A.0., Jr ......... 2243Seitz, M ............... 2146 Tanuwidjaja, A ........... 2137 W illiams, E.G ............ 2223Sessarego, J.P ............ 2265 Taylor, J.S.W ............ 2301 Williams, J.E ............ 2333Shabana, A.A.-E .......... 2331 Teh, K.K ............... 2216 W illiams, J.H., Jr ......... 2313Shah, S.P .......... 2262, 2263 Tepper, F.R ............. 2325 Wilson, R.J ............. 2276Shepherd, R ............ 2152 Thornton, E.A ........... 2347 Windall, S.E ............. 2253Shinozuka, M ............ 2211 Tiersten, H.F ............ 2267 Wong, E.T.............. 2319Sih, G.C ................ 2218 Tsai, K.W.K ............. 2298 Wu, J.J................ 2335Singh, B ............... 2142 Ueda, S ................ 2228 W u, W.-Z ............... 2186Singh, B.P.............. 2142 Van Der Hijden, J.H.M.T... . 2254 Yamada, G ............. 2219Singh, D.V ............. 2204 Van Karsen, C ........... 2296 Yang, T.C .............. 2240Singh, R ............... 2312 van Vliet, M ............. 2177 Yeung, H.C ............. 2231Singhal, K .............. 2328 Varadan, V.K ............ 2238 Zhang, Zhong-ding ........ 2235Sinhasan, R ............. 2204 Varadan, V.V ............ 2238 Ziegler, F .............. 2154Smith, C.B ............. 2340 Verghese, G.C ........... 2298 Zitek, S.J ............... 2178Sm ith, G.M ............. 2178 Wada, H ............... 2221 Zorzi, E.S .............. 2281Smith, P.D ............. 2324 Wagner, P .............. 2232 Zuckerwar, A.J .......... 2257Sofrin, T.G ............. 2309 Walton, J .............. 2281

86

I

1, - .. . 4-

CALENDAR

FEBRUARY 1984 7-11 Acoustical Society of America, Spring Meeting[ASA] Norfolk, VA (ASA lHqa.)

22-24 IAVD Congress on Vehicle Component Design

[IAVD] Gen'wa, Switzerland (Dr. M.A Dorgham, 10-11 12th Southeastern Conference on Theoretical andInternational Associerlon for Vehicle Design, The Applied Mechanics [Auburn University] CallawayOpen University, Walton Hall, Milton Keynes MK7 Gardens, Pine Mountain, GA (J. Fred O'Brien, Di-6AA - (0908) 653945. rector, Engineering Extension Service, Auburn

27-Mar 2 International Congress and Exposition [SAE] University, AL 36849- (205) 8264370)

Detroit, MI (SAE Hqs.)

JUNE 1984

MARCH 1984 26-28 Machinery Vibration Monitoring and Analysis

13-15 12th Symposium on Explosives and Pyrotechnics Meeting [Vibration Institute] New Orleans, LA[Appie 12 hymposium on. Exosrand yresrchncsn (Dr. Ronald L. Eshleman, Director, The Vibration[Applied Physics Lab, of Franklin Research Cen- Institute, 101 W. 55th St., Suite 206, Clarendonter] San Diego, CA (EaP Affairs, Franklin Re- Hills, IL 60514 - (312) 654-2254)search Center, Philadelphia, PA 19103- (215) 448-1236)

20-23 Balancing of Rotating Machinery Symposium JULY 1984[Vibration Institute] Philadelphia, Pennsylvania 21-28 8th World Conference on Earthquake Engineering(Dr. Ronald L. Eshleman, Director, The Vibration [Earthquake Engineering Research Institute] SanInstitute, 101 W. 55th St., Suite 206, Clarendon Francisco, CA (EERI-8WCEE, 2620 TelegraphHills, IL 60514 -(312) 654-2254) Avenue, Berkeley, CA 94704)

APRIL 1984 AUGUST 1984

9-12 Design Engineering Conference and Show [ASME] 6-9 West Coast International Meeting [SAE) SanChicago, I L (ASME Nq.) Diego, CA (SAE Hq&)

9-13 2nd International Conference on Recent Advances 19-25 XVIth International Congress of Theoretical and

in Structural Dynamics [Institute of Sound and Applied Mechanics [International Union of Theo-Vibration Research] Southampton, England (Dr. retical and Applied Mechanics] Lyngby, DenmarkMaurice Petyt, Institute of Sound and Vibration (Ptof. Frithiof Niordson, President, or Dr. Niels

Reseerch, The University of Southampton, S09 Olhoff, Executive Secretary, ICTAM, Technical5NH, England - 10703) 559122, Ext. 2297) University of Denmark, Bldg. 404, DK-2800 Lyng-

30-May 3 Institute of Environmental Sciences' 30th Annual by, Denmark)

Techncal Meeting IJES] Orlando, FL (IES, 940E. Northwest Hwy., Mt. Prospect, IL 60056 - f312) SEPTEMBER 1984255-1561)

9-11 Petroleum Workshop and Conference [ASME)San Antonio, TX (ASME Iqs.)

MAY 198411-13 Third International Conference on Vibration. In

1-3 Mechanical Failures Prevention Group 39th Sym- RTin er y ttion of MebranI

posium [National Bureau of Standards, Washing- Rotating Machinery [institution of Mechanical

ton, D.C.] Galthersburg, MD (Dr. J.G. Early, Engineers) University of York, UK 0~EHqs)

Metallurgy Division, Room A153, Bldg. 223,Phtionei Bureau of Standlrds, W4ashington, D.C: 30ct 4 Power Generation Conference [ASME] Toronto.20234) Ontario. Canada (ASME Nq.)

7-10 30th International Instrumentation Symposium OCTOBER 1984[Instrument Society of America] Denver, CO(Robert Jarvis, Grumman Aerospeor Corp., MAi 8-12 Acoustical Society of America, Fail MeetingStop TO00, Bethpega, NY 11714) [ASA] Minneapolis, MN (ASA hfqs.)

87

CALENDAR ACRONYM DEFINITIONS AND ADDRESSES OF SOCIETY HEADQUARTERS

AHS: American Helicopter Society I FToMM: International Federation for Theory of1325 18 St. N.W. Machines and MechanismsWashington, D.C. 20036 U.S. Council for TMM

c/o Univ. Mass., Dept. MEAmherst, MA 01002

AIAA: American Institute of Aeronautics andAstronautics

1290 Sixth Ave. INCE: Institute of Noise Control EngineeringNew York, NY 10019 P.O. 8ox 3206, Arlington Branch

Poughkeepsie, NY 12603

ASA: Acoustical Society of America335 E. 45th St.New York, NY 10017 ISA: Instrument Society of America

400 Stanwix St.Pittsburgh, PA 15222

ASCE: American Society of Civil Engineers345 E. 45th St.New York, NY 10017 SAE: Society of Automotive Engineers

400 Commonwealth Drive

ASME: American Society of Mechanical Engineers Warrendale, PA 15096

345 E. 45th St.New York. NY 10017

SEE: Society of Environmental EngineersOwles Hall, Buntingford, Hertz.

ASTM: American Society for Testing and Materials SG9 9PL, England1916 Race St.Philadelphia, PA 19103

SESA: Society for Experimental Stress Analysis14 Fairfield Drive

ICF: International Congress on Fracture Brookfield Center, CT 06805Tohoku University

iSendai, Japan

SNAME: Society of Naval Architects and MarineIEEE: Institute of Electrical and Electronics Engineers

Engineers 74 Trinity Pl.345 E. 47th St. New York, NY 10006New York, NY 10017

SSPE: Society of Petroleum EngineersIES: Institute of Environmental Sciences 6200 N. Central Expresswrsay

940 E. Northwest Highway Dallas, TX 75206

Mt. Prospect, I L 60056

IMechE: Institution of Mechanical Engineers SVIC: Shock and Vibration Information Center1 Birdcage Walk, Westminster, Naval Research Lab., Code 5804London SW1, UK Washington, D.C. 20375

88

-- - II I I___________

PUBLICATION POLICY

Unsolicited articles are dccepted foi publication in 0 abbreviated title of journal in which articlethe Shock and Vibraticn Digest Feature articles wui published (see Periodicals Scanned listshould bp tutorials and/or reviews of ireas of interest in January, June, and December issues)to shod b tut rtin/r eginers. o ra fte reiew 0 volume, number or Issue, and pages forto shock ari vibration engineers. L. terature review journals; publisher for booksarticles should provide a subjective critique/summary * year of publication In parenthesesAt papers, patents. proceedings, and reports of apertinent topic in the shock and vinration field. A A sample reference list is given below.k:erat~re rev,ew should stress irrpirtant recenttent nology Only pertinent literature should be 1. Platzer, M.F., "Transonic Blade Flutter - A

Survey." Shock Vib. Dig., 7_(7), pp 97-106cited Illustrations are encouraged, Detailed mathe- July 1976).

(July 1975).matical Gerivations are discouraged rather, simpleformulas representing results should be used. When 2. Bisplinghoff, R.L., Ashley, H., and Half-complex fo'mulas cannot be avoidud, a functional man, R.L., Aeroelasticity, Addision-Wesleyform shuuld be used so that readers will understand (1955).

the interaction between parameters and variables. 3. Jones, W.P., (Ed.), "Manual on Aeroalastici.ty," Part 11, Aerodynamic Aspects, Advisory

Manuscr,pts must be typed (doW)le-spaced) and Group Aeronaut. Res. Devel. (1962).figures attached. It is strongly recommended that linefigures he rendered in ink or heavy Pencil and neatly 4. Lin, C.C,, Reissner, E., and Tsien, 14., "OnTwo-Dimensional Nonsteady Motion ofalabeled. Phot:igraphs must be ur-screened glossy T en so dy otion F aSlander Body in a Compressible Fluid," J.black ard while prints. The form,.t for references Math. Phys., 27 (3). pp 220-231 (1948).shown in N GE ST articles is to be followed.

5. Landahl, M., Unsteady Transonic Flow,

Manuscripts MJst begin with a bripf abstract, or Pergamon Press (1961).

summary Only material referred to in the text should 6. Miles, J.W., "The Compressible Flow Pastbe included in the list of References ait the end of the an Oscillating Airfoil in a Wind Tunnel,"article. References should be cited in text by consecu- J. Aeronaut. Sci., 23 (7), pp 671-678tive ruribers in brackets, as in the example below. (1956).

7. Lane, F., 'Supersonic Flow Past an Oscil-Unfortunately, such information is often un- aigCsaewthSproi ednreliable, particularly statistical data pertinent Edge Locus," J. Aeronaut. S . 244 )to a reliability assessment, as has been previous- pp 6546 J1957).

ly noted (11.

Critical and certain reisted excitations wer Articles for the DIGEST will be reviewed for tech-

first applied to the problem of messing system nical content and edited for style and format. Beforereliability almost a decade ago (21. Since then, an article is submitted, the topic area should bethe variations that have been developed and the cleared with the editors of the DIGEST. Literaturepractical applications that have been explored review topics are assigned on a first come basis.([3-7] indicate that... Topics should be narrow and well-defined. Articles

The format and style for the list of References at should be 1500 to 2500 words in length. For addi-

the end of the article are as follows: tional information on topics and editorial policies,please contact:

* each citation number as it ap-ears in text Milda Z. Tamulionis(not in alphabetical order) Research Editor

* last name of author/editor followed byinitials Or first name Vibration Institute

0 titles of articles within quotations, titles of 101 W. 55th Street, Suite 206books underlined Clarendon Hills, Illinois 60614

1'1

OIPAWIt~FY6I3Y'V',~ ~,< THIRDCLA8S MAA#L

NAVAL RESEARCH4 'T~AORY.O 6 0 SM POSTAGE 6 FEES PAIDMHOCK AND VIBRATION INFORMATION CN111. .. USN

Washingtm OC 2106 PERMIT No.G-9

OFFICIAL PJSNMENOW-NRL 521616M6 1743)

PENALTY FOR PRIVATE UBE. 00

DEF NSE DOCUM1rNATION CENTER

.A, i. R.)'N ST ATONAt.E " \NDRIA, V% 2 2114

THE SHOCK AND VIBRATION DIGEST

VolumuIs.No.. :. November 1983

EDITORIAL 19" EABUJ(tSEMsr&. J' P

I SVIC Neu$ D.W. Nicholson and .J. i man2 Editors Rattle Spae .. /

1//26 -- Bo,-k R e w ia

ARTICLES AND REVIEWS -. / CURRENT NEWS

3 Featur/ A so Short Courses3 ~ ~ TEtr r~~ CHNICAL 33 News Briefs

NOTE ON EVALUATION #i1)AMPERS ABjSTRACT3)P*OM TE CJJRRENT

TV. GoaletiLITERATURE

5 tLitawature Review as8 Abstract Contents..... 36 Ahitrects: 83-2135 to 83-2354

7 8DYNAMIC AIAVIOR 64 Author IndexDEIGROUND StRU S, a.G.D. Manolls CALENDAR

LI

PUBLICATION POLICY

Unsolicited articles are accepted for publication in the Shock and Vibration Digest. Feature articles should be tutorials and/or reviews of areas of interest to shock and vibration engineers. Literature review articles should provide a subjective critique/summary of papers, patents, proceedings, and reports of a pertinent topic in the shock and vibration field. A literature review should stress important recent technology. Only pertinent literature should be cited. Illustrations are encouraged. Detailed mathe- matical derivations are discouraged; rather, simple formulas representing results should be used. When complex formulas cannot be avoided, a functional form should be used so that readers will understand the interaction between parameters and variables.

Manuscripts must be typed (double-spaced) and figures attached. It is strongly recommended that line figures be rendered in ink or heavy pencil and neatly labeled. Photographs must be unscreened glossy black and white prints. The format for references shown in DIGEST articles is to be followed.

Manuscripts must begin with a brief abstract, or summary. Only material referred to in the text should be included in the list cf References at the end of the article. References should be cited in text by consecu- tive numbers in brackets, as in the example below.

• abbreviated title of journal in which article was published (see Periodicals Scanned list in January, June, and December issues)

• volume, number or issue, dnd pages for journals; publisher for books

• year of publication in parentheses

A sample reference list is given below.

1. Platzer, M.F., "Transonic Blade Flutter - A Survey," Shock Vib. Dig.,2<7>. PP 97-106 (July 1975).

2. Bisplinghoff, R.L., Ashley, H., and Half man, R.L., Aeroelasticity, Addison-Wesley (1955).

3. Jones, W.P., (Ed.), "Manual on Aeroelastic- ity," Part II, Aerodynamic Aspects, Adviso- ry Group Aeronaut. Res. Dev. (1962).

4. Lin, C.C., Reissner, E.. and Tsien. H., "On Two-Dimensional Nonsteady Motion of a Slender Body in a Compressible Fluid," J. Math. Phys., 27 (3), pp 220-231 (1948).

5. Lendahl, M., Unsteady Transonic Flow, Pergamon Press (1961).

6. Miles, J.W., "The Compressible Flow Past an Oscillating Airfoil in a Wind Tunnel," J. Aeronaut. Sei., 23 (7), pp 671-678 (1956).

Unfortunately, such information is often un- reliable, particularly statistical data pertinent to a reliability assessment, as has been previous- ly noted (1).

Critical and certain related excitations were first applied to the problem of assessing system reliability almost a decade ago (2j. Since then, the variations that have been developed and the practical applications that have been explored 13-7] indicate that. . .

The format and style for the list of References at the end of the article are as follows:

7. Lane, F., "Supersonic Flow Past an Oscil- lating Cascade with Supersonic Leading Edge Locus," J. Aeronaut. Sei., JJ4 (1), pp 65-66 (1957).

Articles for the DIGEST will be reviewed for tech- nical content and edited for style and format. Before an article is submitted, the topic area should be cleared with the editors of the DIGEST. Literature review topics are assigned on a first come basis. Topics should be narrow and well-defined. Articles should be 3000 to 4000 words in length. For addi- tional information on topics and editorial policies, please contact:

each citation number as it appears in text (not in alphabetical order) last name of author/editor followed by initials or first name titles of articles within quotations, titles of books underlined

Milda Z. Tamulionis Research Editor

Vibration Institute

101 W. 55th Street, Suite 206 Clarendon Hills, Illinois60514