1983 SESA Spring Meeting Technical Program

1983 SESA Spring Meeting Technical Program Bond Court Hotel, Cleveland, Ohio

Monday Morning, May 16 1. Annual Business Meeting and 40th

Anniversary Program West Bal I room

Chairman: S E Swartz Kansas State Univ

9:OOam All members are invited to attend the annual business meeting and special anniversary program immediately following Past-presidents of SESA will narrate a slide presentation of SESA history All past-presidents will be honored and will be presented with 40th anniversary mementos

Monday Afternoon, May 16 2. Optical Methods and Fracture

Mechanics Ritz

Chairman: to be announced

200 pm

230 pm

3:OO pm 3:30 pm

Measurement of Stress and Displacement Fields Near Crack Tips by Optical Methods C W Smith D Post and J S Epslern VPl & SU Use of the frozen-stress-moir6 approach to study the variation in SIF and displacement distributions along cracks in finite-thickness beams approxi- mating fracture-toughness-beam specimens in geometry is discussed Special attention is given to the region where the crack front intersects the free surface of the beam On Extraction of Stresslntensity Factors From Near-tip Photoelastic Data C W Srnrth and 0 Olaosebrkan, VPI & SU The application of several of the full-field methods lo near-tip measurements in order to determine i f two-parameter SIF estimates can be significantly improved for three-dimensional cracked-body problems is considered Two geometries are studied natural surface flaws in flat plates under uniaxial remote tension. and artificial through cracks in finite-thickness bend specimens Coffee break Determination of Stress-intensity Factors of Fillet-welded T-Joints by Computer-assisted Photoelasticity C L Tsar and S K Park Ohro Stare Unlv Three important weld discontlnuities undercut overlap and center-line crack along with the intrinsic flaw are emphasized Stress-intensity factors with respect to the joint dimensions weld dimensions and load conditions are determined using photoelasticity methods A concept of strength reserve of the joint under its design load is discussed based upon brittle-fracture-mechanics theories

4:OO pm

430 pm

Half-fringe Photoelasticity Applied to K Deter. mination for Cracks in Glass C P Burger lowa State Unrv, R Kar M e / Corp and A Voloshm lowa State Univ Half-fringe photoelasticity (HFP) is a new technique which operates with high resolution in fields of low birefringence This paper describes its application to fracture models made from glass Three classes of cracks are studied single-edge cracks double- edge cracks and a 45-deg single-edge crack The stress-intensity factors ( K , K,,) and the far-field in-line stresses are computed

Time-lapse Maid Analysis of Slow, Stable Crack Growth in a Nonlinear Viscoelastic Solid 1 G Rchard. R € Rowlands and T G Ebbort, Un/v ov Wisconsin-Madrson Moire techniques have been employed to illustrate the time- and stress-dependent strains in the near- crack-tip region as well as the far-field response of a nonlinear viscoelastic polymer Using time lapse photographic methods a complete descrip tion of the phenomena of crack initiation propagation and final failure of a high-density high molecular-weight polyethylene was obtained

3. Structural Analysis and Testing Savoy

Chairman: D J De Michele lnst Meas Tech Svcs

200 pm

2:30 pm

300 pm 3:30 pm

Development of a Bird-impact-resistant T-38 Instructor’s Windshield G J Sfenger. Unw of Dayron This program established the existing bird strike capabilily of the in-service T-38 instructor s wind shield and developed four modifications for the production instructor s windshield-support stiuc lure It was designed to maximize the bird impact capability of the windshield while maintaining an acceptable failure mode The experimental design and development of the structural modifications is summarized

Structural Measurements Involved in the Nu- clear-power-plant-containment Integrity Program R L Woodfrn, Sandla Natronai Laboratories Several forms of containment buildings have been tested through the use o f scale models This paper describes the measuremenl techniques used and the most interesting results to date Analytical methods for predicting slructural responses are evaluated Some comparisons between these methods and the measured responses are presented

Coffee break Analysis of Woodcomposite /-Beams with Glued Flange-web Joints R J Leichit and R C Tang AbSurn Univ The short-term mechdnicai bebavior of structural-size wood coniooSite I b r m s wcis wdluated

50 April 1983

at-a r e i a ' x i to ~'op?r:mes 01 !~dO,iioriiiliy used solid wooc fr31iirig !?emen's. 2 in x l i l in an0 2 (11 x 12 ii i ie.1 SixcIrnen5 v:ti't' fabr:c,a!cd using wood-i;3mposiIe slruclural panels as webs and stre,&ri'ia!ed lumber lor flanges Theoretical and experimental results for elastic-oending deflection and ber.ding stress were compared

4. General Session Hassler


2:OO pm

2:30 pm

3:OO pm 3:30 pm

4:OO pm

The Dissipation of Energy in High-strength Friction-grip-bolted Joints (HSFGBJ) M Groper and J Hemmye, Western Michigan Univ Tests were performed on high-strength friction- grip-bolted Ioint specimens made of 1020 carbon- steel plates bolted together at different clamping pressures and loaded tangentially with static and cyclic forces The variation of the coefficient of friction with the clamping pressure and number of cycles of loading were determined These data were used to establish a model of vlbrational energy dissipation in HSFGBJ joints

Strain-gage Applications for Determining Forces on a Baseball Bat G W Eggeman and M L Noble Kansas State Univ An investigation is described to dynamically measure the forces applied by the hands during a baseball-bat swing A strain-gage transducer was designed built and field tested to record the grip- force cycle This force data was related to the movements of the bat and athlete through a film record

Coffee break Effect of R-Ratio on Crack Initiation at External Notches in Autofrettaged Cylinders R R Fulczak. Watervliet Arsenal Experimental work shows the effects of positive- stress ratios or tensile minimum stress during the fatigue cycle on the fatigue-crack initiation from notches This simulates the effect of the residual- tensile stresses at the outside surface of autofrettaged cylinders Results from V notches and square notches are compared to previous results from holes to show the dependence of R ratio upon the stress-concentration factor Experiment4 Values of Orifice-discharge Co- efficient Using Silicone Oil A Akers lowa State Univ Silicone oil has been pumped at pressures of up to 8 MPa through finite-length orifices Data obtained include discharge coefficient pump-sound level and frequency spectrum The amount Of wear on an impingement plate placed downstream of the let has also been measured

5. Residual Stress Dolder Grand Chairman: W E Nickola, Measurements Group. Inc

200 pm Measurement of Residual Strains and Stresses in Transparent Materials A S Redner and W E Nickola Measurements Group Inc Many molded and extruded products exhibit a residual-photoelastic signal This paper addresses calibration procedures aimed at correlating residual

2:30 pm

300 pm

3:30 pm

birefringence in lransparent plastics with orienta- lion-released strains or stresses as described in existing ASTM documents The general procedure IS illustrated by actual calibration of several com- mercially available materials

Residual-stress Evaluation by Ultrasonics in an Elastic-plastic Material W Y Lu Univ of Kentucky The propagation speeds of ultrasonic waves during plastic deformation are investigated The velocities of a longitudinal wave and two shear waves in AL 6061 T6 specimens are delermined under quasi-static tension or Compression cycles The experimental results suggest that the relative change of shear wave velocities is useful for evaluating residual stress Coffee break

Advanced Holedrilling-analysis Method with Experimental Results 8 H Manning Ontario Hydro, R Glover Univ of Waterloo and M T flaman Ontario Hydro A finite-element method was employed to calculate calibration constants for use with the center-hole method to determine the variation of residual stress through the depth of the hole Finite-element models were constructed which simulated the drilling of a hole at various depths in a constant residual-slress field Experimental data will be presented as well as comparisons with calibration constants determined by other researchers

Tuesday Morning, May 17 6. Strain Gages Ritz

Sponsored by the Technical Committee on Strain Gages Chairman: S Reed, Babcock & Wilcox Co

9:00 am Precalibration and Characterization of Weldable Strain Gages M P MacDonald, Babcock and Wilcox Co TCSG From Then to Now R E €kstrom Univ of Nebraska

9:30 am

1O:OO am Coffee break 11:OO am Flow-induced Vibration Studies of Fluidized

Beds Using Weldable High-temperature Gages J K Hayes Combustion Engineering

7. Photoelasticity and Photoplasticity I Savoy

Chairman: H Gascoigne Univ of Utah

9:00 am The Nonlinear Photoviscoelastic Behavior of Polycarbonate E Gamby A Tougui A Lagarde Universite de Poitiers and H F Erinson VPI & SU A theory for a nonlinear-pholoviscoelastic stress- optic law is pioposed The model is patterned after Schapery s thermodynamically based nonlinear-viscoelastic stress-strain const tuiive equation Creep and creep-recovery tests on poiy- carbonate are used 10 deierrrine relevant material parameters and ihe agreement between theoretcai predictions and experimental resu1:s are shown to be excellent

Experimental Techniques 51

930 am

1O:OO am 11:OO am

11:30 am

An Accuracy Evaluation of the Combined Ex- perimental and Numerical Method for the Solution of Elasticity Problems B M Barishpolsky Combustion €ngineering A combined method is presented which is based on the synthesis of experimental and numerical methods Therefore the total error of the solution with the combined method is divided into two groups The first group represents errors of an experimental procedure for obtaining superfluous boundary conditions The second accounts for numerical-analysis errors of the formulated boundary-value problems Coffee break Application of Photoplasticity to an Extruded Polyester Specimen J L F Freire R D Vieira and F V Abinader. Cafho- lic Univ of Rio de Janeiro Plastic strains and their principal directions obtained by the photoplastic method of analyzing deformed but unloaded polyester-resin models were compared and showed good agreement with strains determined from measurements on grids cemented to the plane-extrusion specimens Out-of-plane Displacement Measurement by Standard Photoelastic Coatings Z V Reytblatt A new method for out-of-plane displacement measurement using bilayered SPC is proposed Numeri- cal and optical methods of data processing are discussed A simplified technique lor a symmetrical case is presented

8. Dynamic Stress Hassler

Chairman: D Ozgur. General Electric Company

SO0 am

9:30 am

1O:OO am 11:OO am

An Experimental Method for Determining the Dynamic Contact Law During Impact of Beams and Plates J F Doyle Purdue Univ A new scheme for determining the contact law under dynamic conditions is developed I t consists of impacting a long-beam specimen of the structural material with a small hard object Results from the testing of three materials aluminum glasslepoxy and epoxy, are reported and their behavior compared with static-indentation tests An Experimental Study of the Reflection and Transmission of Flexural Waves at Discontinuities S Kamle and J F Doyle, Purdue Univ The transmission and reflection of flexural waves generated by transverse impact are considered Both a finite-element analysis and an experimental investigation using strain gages are used A unique aspect of the research is the use of a fast-fourier- transform (FFT) computer program to analyze the results and make the comparison between theory and experiment Coffee break Evaluation of Dynamic Stresses in Concrete Under Impact Loads Using Nondestructive Tests 1 Millstein. Sheladia Associates and G M Sabnis Howard Univ The failure of concrete is basically a process of successive fractures by cleavage and the non- linearity in the stress-strain curve relationship occurs due to microcracking A parameter E characteristic of structural-mechanical behavior and the function of the rate Of loading and speed of propagation of ultrasonic waves has been

determined experimentally It shows the nature of the stress-strain behavior Of concrete I e the linear peak at higher strengths and nonlinear shapes for lower strengths even under impact

9. Coherent Optical Techniques Dolder Grand

Chairman: D Post, VPI & SU

9:00 am

9:30 am

1O:OO am 11:OO am

11:30 am

Vibration Studies by Shearography Y Y Hung J Takezaki and J 0 Hovanesian Oakland Univ A new optical method for studying vibrations IS presented An image-shearing camera has been developed to record StruCtUres undergoing steady- state oscillations Time-averaged fringe patterns are produced which depict the slope of the vibra- tional amplitudes Integration of Laser-speckle and Finite-element Techniques of Stress Analysis J Weathers, W Foster, W F Swinson and J L Turner, Auburn Univ Several problems of plane stress have been solved by the combined use Of experimental laser- speckle displacement data and finite-element analysis The potential benefits of such an approach are discussed and demonstrated through examples The effects of experimental error are described

Coffee break Objective Speckle Measurement J H Bennewltz. Umv of Wisconsin-Milwaukee T 0 Dudderar, Bell Telephone Laboratories and J A Gilberf Univ of Wisconsin-Milwaukee A fiber-optic bundle was used to capture a portion of the speckle field generated when a small area of a lest surface was illuminated with coherent laser light The speckle pattern was digitized to determine a characteristic speckle width Changes in this parameter were used to predict object motion along the line of sight Direct Strain Measurements Through Laser. speckle Spectral Density S M Metwalli. Univ of Central Florida This paper presents a new approach to direct strain measurement which utilizes the spectral density of laser speckle The laser-speckle pattern is considered to be a random function representing surface characteristics In this new method strain measurement is achieved through detection of peak shift on the spectral density

10. Fracture Hope

Chairman: C W Smith VPI & su 9 0 0 am Modified Westergaard Stress Function for

Practical Center-cracked Geometry M K Oladirneli Ebasco Services lnc A modification of the Westergaard stress function for the stress analysis of practical Mode I center- cracked geometry is presented The finite-element method was used to study the effects of specimen geometry on the stress distribution around the crack tip The results of this study were then used to obtain a geometrically modified polynomial representation of the stress function

52 April 1983

9:30 am

1O:OO am 11:OO am

11:30 am

Evaluation C! the Validity of Compliance Cali- bration to Estlrnating Crack Lengths in Concrete Beams in Bending S E Swarlz and C G Go Kansas State Univ The Sditdbimity of the compliance-cdlibralion technique to monitor cracking in plain concrete beams in bending was evaiuated using dye penetrant to determine average crack length This was found to be somewhat lesb than that estimated by compliance calibration The compliance method gave excellent agreement when artificial cracks were simulated by Teflon strips in the beams Coffee break Prediction of Crack Propagation in Reinforced Concrete with a Simplified Model A T Andonian and F Ansari Univ of llhnoa at Chicago A methodology is developed which combines reinforced concrete fracture mechanics and threedimensional photoelasticity to find the stress distribution and lo predict crack initiation and propagation in reinforced concrete A new type of specimen is designed and tested in which an epoxy-resin cylinder is reinforced by a lugged aluminum bar Digital-image Processing in Fracture Mechanics S R McNeii W H Peters, W F Ranson and M A Sufton Univ of Soufh Carolina The digital correlation of random speckle phenomena is reviewed in order to lay a solid background foundation for its use in the analysis of cracked- body problems The experimental procedures utilized for applying digital-image processing of random-white-light speckle are presented

Tuesday Afternoon, May 17 11. Strain Gages Ritz

Sponsored by the Technical Committee on Strain Gages Chairman: S Reed, Babcock 8. Wilcox Co

2:OO pm Continued from morning Session

300 pm Coffee break

12. Biomechanics and Life Science Savoy Chairman: W H Peters Univ of South Carolina

2:OOpm A Finite-element Analysis of the Creep Res- ponse of Trabecular Bone in Lumbar Interver- tebral Joints of the Rhesus Monkey W J Rothwell, Jr, A N Palazotfo Air Force In stifute of Technology and E P France Air force Aerospace Medical Research Laboratory An investigation was undertaken to determine material constants describing the creep response of the bony portion external to the disk in order to develop a more realistic biodynamic model for the joint as a whole This study consisted of experimentation and analysis combined in order to establish the viscoelastic coefficients of the trabecular region with the vertebrae of a Rhesus monkey

2:30 prn

3:OO pm 4:OO pm

Torsional Stiffness and Strength of Instrumented Cadaver Spines M Savage A A Mostardi D Betham and G Frohrnapfel Univ of Akron An experimental comparison of two spinal-fixation devices is performed to compare the torsional support provided scoliosis patients by these sur- gically implanted braces The Dwyer cable and the Zielke rod provide primarily lateral support for the lower spine Both instrumentations provide the same amount of torsional restraint on the tested cadaver spines Coffee break A Noninvasive Method for Measuring Planar Velocities and Accelerations J C Anderson D B Rivers, W H Peters and M A Suiton, Univ of South Carolina Velocities and accelerations were calculated from displacement and rotation data for rigid bodies using digital image-processing techniques Experi- mental results were obtained by application of these techniques to biomechanics and the study of vibrations in structures for one- and two-dimensional motion Results indicate a high degree of sensitivity to displacement, rotation and repeata- bility of analytically determined parameters

13. Photoelasticity and Photoplasticity I I Hassler


200 pm

2:30 pm

3:OO pm 4:OO prn

Fabrication of Photoelastic Model J Cernosek, Bell Helicopter Texfron. lnc Inexpensive photoelastic models of good quality are essential to the successful and cost-effective application of photoelasticity in an industrial en- vironment This presentation describes the fabrication of the threedimensional photoelastic models by on shape casting of the fast-curing model material The preparation of light-weight molds and processing (mixing, casting and curing) of this advanced model material is discussed in detail

The Use of Precision Castings In the Three- dimensional Photoelastic Analysis of Threaded Tubular Connections H E Gascoigne, Univ of Utah A new room-temperature-formulated epoxy-resin system with superior stress-freezing photoelastic properties is presented Cylindrical tubes joined by integrally cast Stub Acme and American Standard rolled-thread profiles with typical parameters were loaded in tension and analyzed using the stress- freezing method Results are presented for the axial-stress distribution Stress-optical theological and mechanical properties are given

Coffee break Three-dimensional Photoelastic Studies of ‘Baggi Bye Pass’ Tunnel Internal Pressure D Goldar, Punlab Engineering College and R J Jindal Bechtel Power Corp A photoelastic model of a tunnel whose cross Section was changing from circular to rectangular was prepared from araldite and hardener using an external and internal wax core and a threedimen- sionai photoelastic stress-freezing method The investigation indicated that tensile hoop stress developed when the tunnel was under internal Diessure


4:30 pm Further Studies of Dynamic Crack Branching by Dynamic Photoelasticity M Ramulu A S Kobayashi. B S -J Kang and D B Barker Univ of Washington The elaslodynamic stress field surrounding rapidly propagating cracks In thin polycarbonate fracture specimens was analyzed by dynamic photoelasticity The results of these tests verified the recently proposed dynamic-crack-branching crilerion The branching-stress-intensily factor Klb proved to be independent 01 the initial and branching crack lengths, as well as the thickness

14. Nondestructive Testing Dolder Grand

Chairman:

2:OO pm

2:30 pm

300 pm 4:OO pm

4:30 pm

lo be announced

Diffraction of Rayleigh Waves by an Edge Crack V K Uinra Texas A&M and B 0 Vu. Naval Ocean Sys- tems Center Diflraction of ultrasonic Rayleigh waves by an edge crack has been measured at long inter mediate and short wavelengths Both the tone burst (steady-state) and the ullrasonic-spectroscopy (Iransient) methods were used From Ihe viewpoint of nondeslructive evaluation i t is shown that the crack length can be measured with a reasonable engineering accuracy

Measurement of Clamping Error in Floppy-disk Drives G Prater J r Ohio State Univ A technique is presented for determining the disk elte-centering accuracy of a floppy disk drive Measurement strategy test setup and experi mental procedures are discussed as well as the data-reduction techniques used to complele the analysis

Coffee break A Study of Flaw Identification in Adhesive Bonds Using a Technique of Impact Modification V H Kenner G H Staab and H S Jing Ohio State Univ A small-load transducer has been used to obtain force histories arising from the impact of steel spheres with flawed. laminaled plates The modi fication of the force-time record in the presence of the flaws has been used to detect the flaw for both bonded-aluminum and glass-epoxy composite plates

Spectroscopic Photoelasticity for Studying the Behavior of Surface Waves in NDE C P Burger lowa State Univ, R G Hughes Naval Research Laboratory and A Voioshin lowa State univ This paper describes how spectroscopic procedures were applied to dynamic-photoelastic studies of the interactions between Rayleigh waves and geo metric details on a free surface Photographs from a laser-type Cranz and Schardin high-speed camera were analyzed with a digital video-scan system A fast-Fourier transform analysis was performed directly on this data revealing charac teristic features lor Ihe waves at different stages of their interactions with the artificial defects

15. Dynamic Stress Hope

Chairman: lo be announced

2:OO pm

2:30 pm

3:OO prn 4:OO pm

Measurement of Blast-induced Underground Vibration From Surface Mining M K Phang and T A 8miJSOn, Univ of Alabama Field-instrumenlation studies were performed to assess surface-mining blasting effecls on unoer- ground coal-mine openings Field-vibration data were evaluated to develop suitable damage criteria from which safe operating distances between surface blasting and underground-mine operations could be established Crack Initiation and Growth Under Explosive Loading c R Barnes J Ahmad and M F Kanninen Batteiie Columbus Laboratories A combined experimental and analytical approach to the problem of crack InitiattOn propagation and arrest in flawed ship structures Is outlined Since fracture prediclions cannot be made for these rnatenals using conventional LEFM fracture cnterla a generalized version of the J-integral known as 2 was employed in the analysis

Coffee break Structural Evaluation Of Containment of En- closures with Access Openings A D Gupta and H L Wisniewski U S Army Bal bsric Research Laboratory To evaluate the performance of enclosures during an internal blast the dynamic response of a continuous hemispherical configuration has been compared with the response of a discontinuous structure with an access opening The results indicate substantial alteration of Ihe response behavior and stress concentration in the viciniiy of the cutout region

Wednesday Morning, May 18 16. Optical Methods Ritz Chairman: R E Rowlands. Univ of Wisconsin

9:00 am

9:30 am

Enhanced Displacement Measurements Using a Generalized Formulation for Double-aperture Specklegrams A Wong Alvord Burdick and Howson Engineers M A Sutton Univ o/ Soufh Carolina and Y J Chao Southern Illinois Univ A generalized form 101 Ihe intensity distribution at the observation plane 01 a bpdtially filtered double aperture specklegrarn is derived usmg classical Fresnel diffraction theory The simplified lorrnulas obtained by previous aulhors are lound lo be special cases of lhe general formula A com parison of exper\mental data wilh theorelical results based on the generalized formulation is presented

Digital-image Processing of Finite Deformations T S Chu W H Peters W F Ranson and M A Sutton Univ of South Carolina Ubiquitous wave characteristics resulting from laser speckle or texture due to white light illumination Of a surface are utilized as a measure of finite deformations Global reference and deformed characteristic surfaces are recorded directly in digital form wlth a vldicon camera interfaced to a computer Strain and rotation components are calculated by numerical correlation of small sub sets from the global response of the body before and after deforrnatior

54 April 1983

1O:OO am 11:OO am

11:30 am

Coffee break OpticaLblade Vibration Measurements of an Axial-flow Compressor (0PT.V) H Aoflo ishikawalirna Harirnd H e a v i ipdustries Co New optical-blade vibration detectors and associated d'splay devices have been developed The measurement of model blades working in a vacuum chamber and of test-compression blades are presented The comparison of the test results with the performance of strain gages demonstrates the system s usefulness Mechanical-analog Investigations of Steady- state Thermal Stresses in Slotted Rotors of Turbogenerators G V Rao and A 0 Edone Eharat Heavy €/ectricais Limited The feasibility 01 utilizing holographic-interfero- metric techniques in conjunction with slab analogy is examined and compared with strain-gage and photoelastic methods The holographic-displacement data on a cylindrical rotor are analyzed using the least squares technique to obtain derivatives ot displacements from which strains in the region of interest are computed

17. Photoelasticity and Photoplasticity 111 Savoy

Chairman:

9:00 am

9:30 am

1O:OO am 11:OO am

AS Kobayashi Univ of Washington

An Electromagnetic, Impulsive-loading Device and its Application to Dynamic Photoelasticity T Tobe M Kato N Takatsu and M Mufata Tohoku Univ A new loading device is developed which is driven by electromagnetic force and generates a single loading pulse with an arbitrary duration by using an exploding-wire technique The device attached along the boundary of epoxy models produces well-controlled plane-stress pulses a height of 120 MPa and a duration of 40 microseconds The dynamic stress concentration at the holes is studied

An Assessment of the Accuracy of Orthotropic Photoelasticity M W Hyer and D H Liu VPI & SU Complex-variable elasticity solutions and a stress optic law are used lo predict the fringes in disks loaded in diametral compression These fringes are compared with experimental observation Con- versely the observed fringes and a finite-difference stress separa:ion technique are used to compute stresses in the disks Coffee break Theoretical and Experimental Investigation of the Propagation of Surface Cracks by a Ray- leigh Wave J F Cardenas Garcia and D C Holloway Univ of Maryland The classical solution by Raylelgh and the solutiOn for the application 01 a force at a point of a semi infinite half-space by Lamb for the stress distri bution in the surface region affected by the passage of a Rayleigh wave ( R wave) are examined Using fracture mechanics concepts the propagation of a surface flaw by the action of the R wave is illustrated

18. Measuring Devices, Testing Machines and Systems

Hassler


9:00 am

9:30 am

1O:OO am 11:OO am

11:30 am

A Flexible Microcomputer.based Data-acquisi- tion and Processing System for Welding Ex- periments J E Agapakis and K Masubuchi Massachusetts institute ot Technoiogy A microcomputer-based system that can be used to measure temperatures strains displacements and ultimately process control during welding experiments is presented Hardware and soft- ware is discussed Application of the system in a recent study 01 thermal-stress relief of weldments is also covered

Shock.absorption Characteristics of Athletic Shoes C A Calder C E Smith and J Ying Oregon State Unlv An impact-test stand based on a weight drop with accelerometer measurement experiment has been designed !o compare the shock-absorption capa- bilities of popular brands of athletic shoes Results 01 the heel-impact tests on 10 brands of logging shoes and heel- and ball-area impact tests on 7 brands of basketball shoes are presented Coffee break A Method for Precision Axial Alignment of Tensile Specimens M C Lightfoot and D R Rummler NASA Langley Research Center An apparatus and technique have been developed which reduce the bending stresses commonly associated with tensile tests Specimen alignment is achieved by moving the loading points of crossed- pin universal joints at the specimen s ends where gripping occurs Tensile-test data gathered using both this precision alignment technique and more typical laboratory testing procedures are compared for graphite-epoxy specimens Researching the Soil-machine System by Means of Mathematical-statistical Methods T Adreakos P A Drakatos Univ of Patras and N Kotsovinos Univ of Thrace This paper describes soil behavior characterizing its local properties using a tensors method and an approximation based on the geometrical properties of soil deformation Many common types of soil including those produced by the use of construction equipment are studied

19. Composite and Reinforced Materials Dolder Grand


9:00 am Tensile Stress-Strain Behavior of Hybrid Com- posite Laminates J M Kennedy NASA Langiey Research Cenier Hybrid composite lamiiates were loaded in tension to study their stress-strain response The laminates had epoxy matrices with laminde of S-glass and graphite fibers Kevlar and graphite fibers and graphite fibers with layers 01 mylar Detween plies Results showed that the ultimate strain of the fibers in the load direction governed hybrid taiiure


9:30 am

1000 am 11:OO am

1130 am

Longitudinalcompression Failure Modes in Fiber-compositeend-attachment Effects C C Chams and J H Sinckir NASA Lewis Re search Cenrer In order to assess end-tab debonding effects and the effects of any eccentricities on failure modes a detailed finite-element analysis was performed on both thick and thin specimens The finite- element model used in the analysis consisted Of quadrilateral-anisotropic plate elements Five elements were used across the specimen width to capture possible twisting effects

Coffee break Application of Computerized Moirh Technique to Study Fracture in Filament-wound Composites A Hunter T Milly D Lapicz and J Bleletich Lockheed Research Laboratory Recently developed computerized moird techniques to perform high-sensitivity experimental strain analysis of filament-wound composite materials to aid in the evaluation of their StrUC tural response are considered The complete strain field in the vicinity of surface flaws in race- track-type specimens of Kevlar epoxy and fiber- glass epoxy subjected to tension loading were determined Mechanical Behavior Testing of Composite- tubular Specimens A R Cederberg, Brunswrck Corp , R F Fofal. Univ of Nebraska Lincoln and A G Reiners Brunswick Corp This paper describes the test specimens special apparatus and test procedures developed to characterize mechanical behavior of filament- wound composite materials under uniaxial and biaxial loading conditions The technique may be used lo evaluate mechanical response of tubular specimens to axial tension or compression in com- bination with internal pressure Typical test data and analytical considerations are presented

20. Stress Concentrations Hope

Chairman: J Phillips, Univ of Illinois

9:00 am

9:30 am

The Effect of Proximity of the Free Edge on the Maximum Stresses at a Near-edge Elliptical Hole in Transient Photothermoelasticity C Y Chou, I Miskioglu and C P Burger lowa State univ Photothermoelasticity is used to study the transient thermal-stress field at the elliptical boundary of a defect that is near a free edge subjected to a rapid temperature change The effect of the ligament size ( I e , the minimtm thickness of the material between the ellipse and the free edge) on the stress field is investigated An equation that predicts the maximum stress at time y after the onset of the transient is presented

Evaluation of Fatigue Strength of Welded Structures by Local Strain Measurements 8 Atzori G Blasi and C Pappalettere. Univ of Bar, This paper presents an experimental evaluation of the local strain conditions in proximity with the most probable fatigue-crack starling zones of welded structures-at the toe of welded joints The evaluation is performed using strain gages and finite-element techniques on real cruciform welded joints The possibilities and the limitations of strain-gage measurements for the assessment of fatigue strength of existing structures are discussed

1000 am 11:OO am

Coffee break Local Least-squares Photoelastic Solutions at Stress Concentrations D G Berghaus, Georgia Inst/tute of Technology photoelastlc data, stress-equilibrium relations and static-equilibrium conditions are combined in an overdetermined solution for stresses in the vicinity of stress Concentration (concave-surface radius) A least-squares solution which can be employed with small programmable calculators is used for the small region The method is applied to stress analysis in the vicinity of a notched beam in bending

Wednesday Afternoon, May 18

William M. Murray Lecture East Ballroom Chairman: S E Swartz, Kansas State Univ Murray Lecturer: Albert S Kobayashi Univ of Washington

1:00 pm Hybrid Experimental-Numerical Stress Analysis Hybrid experimental-numerical stress analysis- although i t saw only limited use in the 1950 s-IS now being resurrected as a viable tool in stress analysis The author attributes this occurrence to the fact that more experimentalists are accepting the finite-element method as a tool for numerical experimentation The complementary roles of experimental and numerical stress analysis will be demonstrated and results obtained through their combined use presented

Thursday Morning, May 19 21. Transducers Ritz

Sponsored by the Transducer Technical Activity Commitfee Chairman: D Fussey Schaevrtz Engineering

8:30 am The Inclinometer J E Trotra. Schaevitz Engineering The inertial-grade servo-accelerometer has been applied as a transducer to measure slopeitilt For this function. the classical accelerometer has been modified into a high-precision inclinometer Appli- cations include gun-elevation control surveying bore-hole mapping robotics and industrial-process control

The Use of Sensitive Temperature Transducers to Produce Stress Maps of Cyclically Loaded Structures D J Berry and D E Oliver Omerron Ltd A remote highly sensitive infrared sensor can be used to measure the minute temperature changes that are directly related to surface stresses generated by cyclic loading of structures This paper describes the thermoelastic principle upon which this technique of stress measurement is based the use of infrared transducers to achieve the required temperature sensitivity and the correlation of the technique with other theoretical and practical methcds of stress analysis

9:00 am

56 April 1983

9:30 am

1O:OO am 11:OO am

The i)eita Element Reusable Strain Transducer

1-in gage-lenytn insirunient has been constructed and bhowii i o have an accuracy 01 Seller than one percent Applications are discussed

Coffee break Development and Calibration of a Dynamic Contact-force Transducer D Goidar. Punjab Engineering Coilege. V S Sethi. 0 P Khurana and S R. Verma Terminal Baliistics Research l a b A dynamic contact-force transducer was developed using a pair of quartz crystals as the sensing element Calibration was accomplished by com- paring experimental results with the numerical solution of the Timoshenko-beam equation The transducer was subsequently used to study transverse impact on simply supported beams

22. Damage Documentation in Composites

Savoy

Sponsored by the Fracture and Composites Committee Chairman: G Sendeckj, Wright Patterson AFB

8:30 am

9:00 am

9:30 am

1O:OO am 11:OO am

11:30 am

Characterization of Internal Damage in Graphite- epoxy Composites by the Deply Technique S M freeman lockheed Georgia Co A partial pyrolysis deply technique developed for characterizing damage and defecls in graphite epoxy composites on a lamina by lamina basis IS

described Load-induced damage such as fiber bundle fracture delaminations and splitting O f matrix cracking parallel to the fiber direction of a lamina is discussed and illustrated for impact static and fatigue conditions

A Critical Assessment of Ultrasonic and Radio- graphic Methods Used to Map Microstructural Features in Composites R i Crane Wright Patterson A F B

Computer.enhanced Video Reconstruction Of Stereoradiographs of Damage in Composites G Maddux Wright Patterson Aft3

Coffee break Relationship of Damage Accumulation to Frac- ture Processes in Composite Laminates K Reifsnider and A Highsmith VPI & SU

Moird Interferometry for Damage Analysis of Composites D Post VPI & SU Moire interferometry olfers high-sensitivity rned surements of in-plane displacements Tne basic technique is reviewed and applications lo Corn posiles are shown Disparities in nominally uniform plates can be analyzed by opticdlly subtracting the uniform displacement field from the total displacement field

23. Residual Stress Hassler

Sponsored by the Residual Stress Committee Chairman: M T Flaman Ontario Hydro Cochairman: J J Yavelak Babcock & WilcO~ C O

8:36 am

9:00 am

9:30 am

1O:OO am

11:OO am

Nondestructive X.ray Diffraction Residual-stress Measurements Inside Stainless-steel Piping C 0 Ruud P S DiMasoo and D M Meicher Fenn sylvania State University This paper describes nondestructive proceduies and demonstrations which provided ahsolute residual-stress measurement on the inside surface of pipe specimens A Ruud-Barret: position- sensitive deleclor was used lo build an EPRI-pipe stress analyzer for these residual-stress measurements

Investigation of Machining Stresses in a Large Alternator Rotor E Procter and D H Mitchell Centra! Eiectricily Generating Board Cracking in a 660-MW rotor was ini!lated by a fretting-fatigue mechanism 1nvestiga:ions demon- stratea the influence of Ihe relationship 01 slructural integrity to the residual-srress fieids Resiouai- stress measurements were maae using the center^ hole technique and adaptalions of the techniaue as described in the paper

Consideration of Near.yield Residual-stress Measurements via the Blind-hole Method W Nickoia Measurements Grodp. inc Uncerlainties in the measurement of near-yeld residual stresses are considered via eroe~imerlz.1 analysis Loading was confined 10 a k?ov,n Lnidxidl

tensile-stress field and rneasilremen:s Y:eri:. maae using a conventional tnier-eienerl rosette Photoelastic coalingh we examine localized yielding in the v,cini!y 01 t t x 'Ioie

Coffee break

Measurement of Residual Stress Due to Welding D R Lee and C T Jones. Babcock & Wilcox The residual-stress distribution due to welding was measured on a flat-plate weldmen: using X-ray diffraction The surface and subsurface residual slresses were measured using a portable residkal- stress analyzer Subsurface residualLst'es< med- surements were oblained by removing metal lavers which varied from 1116 in to 114 in ir1 deplr-

24. Education Dolder Grand

Sponsored by the Education Committee Chairman: P D Hcimdah: U S Mil 'tdiv Acaaernr

8:30 am Differentiation and Integration of Continuous Experimental Data D G Berghatis and T Woods Gesrg.,i I Technology Melhods in d .;lidoen: ekoe'8int=ni for in ! eg r a t i ng P xpe r i me n t a I Oat elec:ric acceleromete' and iron' .i

different8al transformrr Da!d A

linuot.s and discrete !o,m C il programmable cdicd;d:c, scope are usea lo dss~s: wilt1

Ekperi men ta I Techniques 5 7

9:00 am

930 am

1O:OO am 11:OO am

11:30 am

Beams of Multiple Materials-A Theoretical Approach C G CParnSers Laarence lnst tute of Technology All mecnanics of materials texts lreat beams Of more t ran one matertal by an equivalent SfXtiOn- wDere one material is replaced by an elaStiC equtvalev' area of another material This some 5mes leads to odd snapes or approximations for example a circular rod being replaced by a rec tangle rather tnan an ellipse This paper begins with tne origin of the Flexture formula and derives severdl related formulas

The Development of Viiinstructional Materials for a Consistent Sequence of Experiments in a First Course of Strength Materials R G Budynas and W Walter Rochester lnstitute of Technology Oftering and stalling laboratory courses has be I ome iricreasingiy difficult in recent years This paper discusses an approach which seeks to eliminate the conventional laboratory format in volving faculty supervision and grading Six inSlruC tiondl video tapes were developed for the laboratory tor a first course in strength of materials

Coffee break The Cantilever Beam as a Vehicle for Teaching Engineering Mechanics L D Leinback Measurements Group lnc Photoelastic Demonstrations of Simple Stress Concentrations and Stress Freezing 13 W Cotterman a n d R A Bodre U S Military Academy Two brief inexpensive pnotoelastic demonstrations for class instruction or industrial briefings are presented A ten minute demonstration of stress freezing producing an actual stress frozen speci men is outlined Lastly stress frozen specimens under equal uniaxial loads are used to demonstrate stress concentrations from notches of varying dimensions

25. Moird Interferometry Hope

Chairman: T G Richard Univ of Wisconsin-Madison

8:30 am

9:00 am

9:30 am

Deflections and Strains in Flat-plate Structures Using ProjectionmoirB Method B B Raju B S West and A J Piekuiowski Univ of Dayton Research institute A projection-moir8 method was used to determine both the surface out-of-plane deflections and strains in flat plates subjected to static loads Results compared electrical strain-gage and dial- indicator data with such theoretical data as small and large deflection-beam theories and small deflection-plate theory

Moird Interferometry with f 45-deg Gratings R Czarnek and D Posf VPI & SU Specimen gratings with rulings oriented to + 4 5 deg and - 4 5 deg to the x axis can be used to determine the U and Vdisplacement fields I e the displacements in the x and y directions The analysis leading to this conclusion is presented The advantages of this method are related to the construction of the apparatus for moire interferometry

Whole-field Strain Determination by MoirB. shearing Interferometry E M Weissrnan D Post and A Asundi VPl & SU A moire-interferometry arrangement was used with an optical-shearing element in the viewing

1O:OO am 11 :00 am

system An adjustable air wedge located near the common focal point of a telecentric lens produced [he Shear Excellent experimental verification was obtained with shears of Only 0 58 mm (0 023 in )

Coffee break Stress-intensity-factor Determination from Dis. placement Fields D B Barker R J Sanford and R Chona Univ of Maryland This paper examines the feasibility of extracting the stress-intensity factor and associated higher order terms from in-plane displacement field data Results of a series of numerical experiments con ducted to develop a K-determination algorithm are discussed as well as some experimental results where K was calculated from moirk-fringe data

Thursday Afternoon, May 19 26. Transducers Ritz

Sponsored by the Transducer Technical Activity Committee Chairman: D Fussey. Schaevitz Engineering

2:OO pm Continued from morning session

27. Dynamic Fracture and Fragmentation Savoy

Sponsored by the Fracture Committee Chairman: L S Costin Sandia National Laboratories Co-chairman: W L Fourney. Univ of Maryland

2:OO pm

2:30 pm

3:OO pm 3:30 pm

Fragmentation Under Impulsive Stress Loading D Grady Sandia Nafional Laboratories Theories based on Mott s dnalysis and the Boltz man equipartition-of-energy concept appear to pro vide upper and lower bounds on the variance of dynamic fragment-size distributions Certain trends in fragment-size data seem to relate to the multi plicity of the fragmentation event These concepts will be considered in terms of recent iragmenta- tion data obtained through gas gun torsional bar magnet and explosive-loading methods on both ductile and brittle materials

Fragmentation Studies in Jointed Brittle Materials D C Holloway and W i Fourney Univ of Maryland The interaction of explosively generated stress waves with joints and major flaws in brittle materials and the resulting crack growth and fragmentation is described Dynamic photoelasticity and high speed photography were used to record the failure of plates of Homalite 100 and several types of rock The results show that joints play a significant role in explosive fragmentation

Coffee break Fracture and Break-up in Uranium Dioxide R W Marshail Jr EG&G ldaho Experiments have been performed with depleted and spent zirconium-clad uranium dioxide (UO,) shock loaded in various ways Fracture patterns observed for hrreched and uribrerched cladding and diffrrences in particle size dislrihc!'iori between depleted and spent GO, W I I be discbsced In spent UO, radioscope stpaidisor from the bulk matrix

58 April 1983

4:OO pm

4:30 pm

vdaS o b s i 1 ~ e 3 M r J c - 5 TTpIicLi'ioris i ~ i l l be re viewio The Relationships Between Rock Structures, Delay Timing, and Fragment Size and Distri. bution in Explosively Loaded Rock S R Winrer Martin Marietta Laboratories Studie- of fragmentalion have been made in re- dbced scale benches and at full production scale using fixed bore hole geometries and carefully controlled explosive changes Inputs from all the parameters studied are proving useful in the design 01 blasting rounds to control fragment size and distribution Explosive Fragmentation of LWR Spent Fuel and U02 R P Sandoval Sandia Nalional Laboratories and G J Newron Lovelace Foundation for Medical Evaluation and Research Experiments subjecting zircally clad depleted UO, fuel pins and six-year-cooled spent-fuel pellets to explosive attacks were conducted to provide data characterizing the aerosol and fines produced from spent fuel subjected to sabotage environments Aerosol-size parameters as a function of time were determined using cascade impactors filters electroslatic precipitators and time-resolving rotating plate samplers The results of the analyses and the implications on the regulations governing the transport of civilian-reactor spent fuel will be discussed

28. Residual Stress Hassler

Sponsored by the Residual Stress Committee and ASTM Chairman: M T Flaman Ontario Hydro

2:OO pm This joint SESAlASTM meeting on residual-stress measurement will include Results and Evaluation of Phase I Round Robin Study on Residual-stress-measurement Methods M T Flaman Ontario Hydro and J Yavelak 8dh cock & Wilcox Company

SESA Residual Stress Business Meeting Joint discussion of round.robin investigation of near.zero residual stresses ASTM €26.1.3 Business M e e t i v

29. Composites Dolder Grand


2:OO pm A Comparison of Several Methods of Calculating Fracture Toughness from Composite-laminate Test Data C E Harris ai id 0 H Morris VPI & SU Experimental data has been obtained from center- cracked tension specimens of T300-5708 graphile- epoxy laminates with three diflerent slacking se- quences and several thicknesses In each case fracture toughness has been determined using finite-element stress analysis and the comrdiance- calibration method The two methods are compared and the discrepancies between them are discussed

2:30 pm

3:OO pm 3:30 pm

4:OO pm

Creep and Creep Recovery of SMC.RS0 at Room Temperature S C Yen C Hie/ and 0 H Morris VPI & SU The creep and creep-recovery behavior of SMC- R50 at room temperature and constant humidity was investigated experimentally and theoretically The strain time response for constanl load was modeled using the Findley equation Two types 01 step loading were used lo verily the model Coffee break Nonlinear Viscoelastic Characterization of Uni- directional Composites in Hygrothermal En- vironments R Mohan and D F Adams Univ of Wyoming Tesl facilities were developed to conduct tension and compression creep-relaxation tests required for the viscoelastic characterization of composite materials Experiments were conducted using unreinforced (neat) epoxy material as well as uni- directional graphiteiepoxy and glassiepoxy composites Finite element micromechanical-analysis predictions were made for comparison wilh the lime-dependent behavior of the composites The Accelerated Characterization of Com- posites C C Hiel VPI & SU A H Cardon Vri/e Universiteif i3russels and H F 8rinson VPI & SU Creep and creep recovery tests at different stress levels and over a temperature range from room temperature up to 340°F were conducted on T3001934 graphite-epoxy laminates in order to describe the transverse and shear response Neat 934 resin was characterized over the same temperature range in order to come to a better un derstanding

30. Holography Hope

Chairman: T D Dudderar Bell Telephone Laboratories

200 pm Holographic Moire for Deflection of Plates S K Chawla. Goodyear Research A double-illuminalion hologiaptK moir6 was npplied to obtain normal defleclion 01 pldlt?s wi!h reduced sensitivity The sensitivity of defleciion can be controlled through illumination direcifor>s of :wo beams The moire patterns of no ima deflection of dillerent sensitivities are obtained tor a lhinclampeo plate subjectea lo delleclion a1 ihe centcr A Note on Optical Differentiation with White- light Wavefront Reconstruction S K Chawla. Goodyear Research d n b C A Sciam marelia Illinois Institute of Technoio,;y The holographic-moiri; pattein Of a drspiacenleni component placed I:: a Fourier optical-tranilorm system using white Lghl as lhe source produces a light spectrum at eacP diffraction o:aer tn tile transformea irnace plane The pa':erni 0 1 oc lives of disolacement is obtaint'o DV ti le sL,pt 'r~ position 01 ,maQes trom the ccmp1emer:ari c@ior., 01 the ligh! specirum

lsopachic Contouring of Opaque Plates D Post R Czarnek and A A s u r ~ d t VF I 6 SU A simple reflect~on-loiograpnv : e C b w b e on two sides of !re soecsmer 'o D ~ O G U C ~ of OUt-@t-olafle d'spi2cerne":i D

Since the car"e1 ' t n g e i for !

2:30 pm

3:OO pm Coffee break 3:30 pm

'eO..e';c e5 t.>' OCPCI:


4:OO pm

4:30 pm

ineir s~,perpos~; 01 gave lhe additire moirk pattern or t re sum of the out of-plane displacements which served as a whole-field contour map of cnange of mecimen lhtckness

A Technique for Direct Readout of the Deriva. tives of Holographically Recorded Displacements Y Y Hung P D Plotkowskt and J D Hovanesian dakland Univ A method which permits the direcl readout of the aerivalives of holographicdlly recorded displace ments has been developed This is accomplished by creating a holographic carrier Ihe pitch of which is altered according lo the slope Of the displacements The readout process IS based On a dilliaction technique which provides variable sensiiivity

Remotedisplacement Analysis Through Different Media Using Fiber Optics J A Gdbert Univ of Wisconsin Milwaukee D Dudderar Be// Teiephone Laboratories and A Nose Univ oi Wisconsin-Milwaukee Oplical fibers were used lo record holographic interferograms in different media with and withoul vibralion isolation Experimental results and as sociated discussions demonstrate the potenlial for recording displacement in production relaled or in s t u applications many of which require tesling on remote surfaces in hostile environments or in media other than air

Proceedings of the 1982 SESNJSME Conference

on Experimental Mechanics

If you missed the largest technical program ever sponsored b y SESA, held in Hawaii, May 24-29, you can still obtain a copy of the conference proceedings.

Over 180 papers ?n composites, photoelastic methods, fatigue, moire, vibrations, fracture, structural analysis and testing, optical techniques in fracture mechanics, rock mechanics, measuring systems and devices, elasticity, residual stress, speckle techniques, dynamic stresses, acoustic emission, pressure vessels, fracture testing of poly- mers, holography and many more subjects are fully illustrated and referenced in this large, two-volume edition.

This important conference proceedings is available to SESA members for $50.00 and to nonmembers for $60 00. All orders must be prepaid. Outside of North America, add $5.00 for postage. Send orders to SESA, 14 Fairfield Drive, Brookfield Center, CT 06805.

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60 April 1983

Documents

1983 SESA Spring Meeting Technical Program