Fracture of Moment Connections

HIGHLIGHTS OF

MOMENT CONNECTION DETAIL

FRITZ ENGINEERING LABORATORY LIBRARY

TEST NO. 1

by

Abbas Pourbohloul

· George C. Driscoll

l E H I G H /F l /4 6 9--6

F. l. R e port No. 4 6 9. 6

Fracture of Eanent Con.T'lections

HIGHLIGHTS OF l'~ CONNECI'ION DETAIL

~..sr NO. 1

by

Abbas PourbOhloul George C. Driscoll

This \YOrk has peen carried out as part of an investigation sponsored by grants fran .f..merican Iron and Steel Institute and the national Science Foundation (Grant No. CEE-8022041) •

. Reproduction in vmole or in part is permitted for any purpose of the United States Government.

Der...ar:tmcnt of Civil Engineering

Fritz En0incering ~~oratory Lehi0h University

r.eth1eh~-n, P£nnsylvania 18015

LF.lliGI:/FL/,160--6 Fritz !n~1ince:::-inq L:1t-oratory Perort r:o ·'i-69. 6

469.n 6Jan81

1 AESTPAcr 2 H7riDDUcriON 3 DESCRIPTION OF 'IEST

3.1 Test Program 3 • 2 Specimens 3.3 Test Fixture 3.4 Test Setup

Table of Contents

3.5 Details of· Specimen (Test 1) 4 Test Results 5 Plans for Re-Testing 6 Conclusions 7 ACKNOl·UJX;D,!E!-ITS

l

1 2

. 4 4 4 5 5 6 6 7 8

10

45'?.G

1 ABSTRACT

A tension test of a simulated detaiJ of a heam-to-column web.mament

con.l'"lection •,;as coniucteC. as part of the experimental \\Drk in a study to

detemine r:1ethoos to prevent fracture of this type of connection.

Preliminary results thearetical and experimental

loa,J.-nefleetion curves and a description of a failure by fracture are

described. The specimen successfully sustaiD.ed lcx1ds up to approximately

1 • 35 ti.TTies ·the naninal yield stress of : the material and overall

elongations of a simulated beam tension flange of approximately 6 times.

the naninal elongation to cause yield. A fracture CCT.)pletely severed the

siMulated beaTTI tension flange after this load \·Jas achieved. Initiation

of the fracture v~as at tack \·.telds used to .fasten a backing bar provided

to p2nnit groove-\-lelding.-t::he si.1"!1ulatec1 beam flange to a connection plate.

~1e fracture suggests the neee for further attention to details involving

tack "'elcs in con.l'"lections Where ductility is required such as in

structures designed by plastic design, structures designed for earthquake

resistance, or structural designs •.vhich ta~e advantage of the

redistribution .of · T:101'7lent provisions of allo.r~able stress design. A

non-linear elastic-plastic analysis gave good agreement ~~th the

exrerimental load-_deflection hehavior up to the naninal yield stress of

the S?EC :L-nen •..

. ·The nonlinear elastic-plastic analysis \·;as conducted in preparation

for fracture anaJ.yses of the connection v.~--,ich \·Jill constitute the ·r.-,nin

anr"J.lytical part of this research. !b·.tever, a nonlinear fracture analysis

night be more suitable in this task.

Results of this a1'10 other tests plus a theoretical analysis of the

con!'lection •:1et.C'lil \,·ill constitute a "basis for gui~elines and

recomcnr• ations for future of beam-to-colunn ,.,eb

connections.

459.6

2 IN'I'ROIXJCI'ION

The concept for. the current research progra?!l originated as a .result

of a series of tests perforn~l to investigate the str~ngth of full-scale

be~to-colLrm v~b moment connections [~entschler, l?Pn]. ..

~~ out of four specimens tester1 exhibited premature failure due to

fracture. It was suspected that material defects or unsatisfactory

·welding were· the cause of fracture. Ho..,rever, further metallurgical and

chernical tests ruled out this possibility. The tests indicated that the

material and welds v1ere reasonably nonnal. It was .concluden that the

prL~ary causes of the fractures were stress conditions Which were due to

restraint provided by fastening the tension flanges . of the bea.'1lS to the

heavy column flanges (Driscoll, 1979]. The current research program was

proposed to deterr1ine haw to avoid fracture problens in beam-to-column

web . connections.

TI1e research plan was to first isolate the tension flange connection

detail and then apply the results. to a study of the "'nole connection. A

physical and. mathematical rncx1el of the tension flange detail was

fornulated consisting of a short length of a colUmn, a flange connection

plate, and a plate sL~ulating the tension flange of the bea~. In this

r1cx1e1, the · princiyx"ll ·varia'-)le w"as the flange connection plate.

Vari.ations in the shape, t'hicY'..ness, an0. pattern of \·lelding to the column

rrcvi(1ed the range of different oetails studied. The connection plate

an~ the simulat~ tension flanoe plate were .to be fastened perpendicular

to the web rlane of a 4-fCX>t long column stub at its center. This

asse~lage would be supported as a simple be~ at the ends of the colunn

stub. ;.. tensile force v.nich \·.10uld create m:::r:1ent about the v.reak axis of

the colllr.".n v.Oulc'l be appi ied on this_ tension rlate. Effects of the beai::

\:eb, 'Dearn shear connection, and the beam compression flange vJerc

neglected in trle :rrelirninary l"'':'lel. :'his assumption, with a ruc1inentary

analytical justification, \·Jas r"'ar'le in order to achieve an economical

r.n4~1 for both cor.putntional a~d exr£~~ental purposes.

.. .. stlYJy of el[lstic stress dist_rihutions of several

rlet<1ils ~::as carried out usin0 a linear finite element program [Bathe,

1 ?7~ J. The raranctric analysis •.-as conducted as a first step, to

evaluate the effect of l'lifferent thick.11esses and geanetries of the flange

connection· plate on stress concentration. ·This analysis helped select

2ppropriate oetails for a second step of analysis. "· ca;1plete repJrt on

tr.e elastic para-:1etric study has been preparec1 [Shen, 081a].

l\n elastic-plastic step-by-step loac1-deflection a."1a1ysis •,vas carried

out on a series of simulated tension flange connection details adopted

from the results of· the parametric analysis. . Figure 1 shavs layout and

r:'.irnensions of the plates used in the elastic-plastic analysis. case A

represents ITOst nearly one of the • specimens that fractured in the

full-scale beam-to-rolumn web .. connection .tests. Case B is the same

detail, but with a l-inch thick stiffener supplied. Both case ·A and B

were analyzed vlith the joint of. the simulated beam flange flush \'lith the

plane of the tips of the column flanges, aithough it vJOuld not be a

sui table joint for welding. However, no specimens were fabricated ··this

way. case C has the connection plate tapered . and extenned 3 inches

beyond the flange tips to move -the- joint to the beam flange away fran the

zon~ of restraint between.the column flanges. caseD i~ essentially the

same detail as ~ase ·A, but a thicker 1-5/8 inch connection plate is used

to reduce the stresses in the connection plate. case E uses a 1-5/0. inch

cormection plate, but no weld is to be apPlied bet\':een the connection

"!Jlate and the column web. case F has the same detail as ·case C but has a ' thicker connection plate to investigate the effect of reducing the basic

stresses. case G Has studied to observe the effect of an extended

tapered connection plate not uelded to the colU'TU1 .,.,eb. The analysis of ..

these details v<as carriee out throug1l a step-by-step procec1ure using the

linear finite ela:1ent prograr.1 Sl\P4 [Bathe, 1974.]. The results of these

stu~ies have been reported separatE:ly C~er., 02.lh]. ':'hat rep::>rt contains

step-by-step loa.~-~e.::10etion curves, stress distributions, nnc'l sketc1-:es

cf yielding patterns.

Easer3 on the tv..o analytical stl.Xlies, a phase of desiqn, fabrication, ·

2n~ testing of sanple oetails '..Ja.s r.-eoun. ':'his re:.crt covers the

~:ic:;'1lig11tS of t'hc first simuluted connection det3il test.

1

3 DESCRIFTION OF .TEST

3.1 Test Program

Certain of the details previously analyze.'() '•Jere. to be tested with

anc Hi thout backup stiffeners opp:::>si te the tension flange connection

plate. }\n overall view of the test setup is sho\m in Fig. 2 and a list

of tests v1ith their scher:1atic details has been srnrrnarized in Table 1.

.Speci~~~s A and C represent the corresponding cases in Fig. 1. Specimen

B represents case A, but with an extended connection plate (about 3

inches) . Specimen D represents case E of Fig. 1 and specimen E

represents case G.

The· effects of different thicknesses ann geometries and the

contribution of the column \;eb in transferring .tensile force into the

col urr.n flanges were considered in different specil'!'lens. The contribution

of the column web in transferring stresses came into· effect via the

presence of a fillet weld along t.lje flange connection plate and column

web.

3 ~ 2 Specimens·

Fig~ 2 gives a schematic view of a typical specimen and its position

in the test setup. The s~cmc.'1s V!ere fabricated frO!:\ A.S'TI~-!>.572 grace 50

steel v.rith a colur:m size of 1·:J.4x:257. This colurm section was chosen to

sintilate the connection size \vhich had failed in previous

tests [Pentschler, 19g0]. For t.'i-le sa'Tie reason, a 10-inch wide tension

flange plate vJas adoptee!, simuluting the flange of a beam. :'he length of

the olate \ ... o.s 5. 0 feet to provide adequate distance frcr.l the grips of the

testinq nacrine and to ensure that St. Venant's principle holds.

1\10 r.echanical ~roperty tests have ceen carrie<-3 out ut this staqe of

testing. The yielo stress level of the material was o..r-proxirnately 54.0

}~si. Fiq. 3 shows the stress-strain cu..."-ve \·n:l.ch was obtained fran one of

these tensile tests.

r. Jeld ing •,•,as in <:lccordance with the l'>NS Euildinq Co:le [l'-merican

\:elr!ing Society, 1020:. J\11 welds \·Jere fabricated using I::-70XX

electroces. Fillet vlelr3 sizes '.:ere measured ann -checked against their

·ncr:>.inal volues and all were sound \lit1:out cracks according to a visual

46~.6

inspection.

ASTI':-A4 ?0 rol ts were usee in assembling the tol ted parts. All

rol ted joints were designed as bearing type and ar: allo..rable design

stress of 40 ksi, in shear, \;'aS used.

Because of the relative strengths of the colunn rrenl::-er and the plate

material, failure we>uld occur in the tension plat~, but not in the

column. Because of the survival of the column section, each stub colU'Til"l

could be used tv1ice, once without a back-up stiffener ann then with a·

back-up stiffener. In order to ~euse the s:pecimen, the flange connection

plate v.ould be burned off at the tip of the column flange and parallel to

thE: column \·leb to remove the remaining damaged. parts of the first test.

7hen a fresh connection plate and a flange plate \~uld be weldec1 to -~e

reverse side of the collliT1n, serving as a ne-w test specimen. The

burned-off connection plate fran _the first test v.ould serve as the

back-up. stiffener.

3.3 Test Fixture

The test fixtures are also depicted schematically in Fig. 2. 'J:\..lo

- reusable rol ted enn plates were "tol t~ to ·welded. end plates on · the

speci.r1en. The end plates \..Tere rolte~1 in tUrn to a fixture nearly the

sa1:1e in appe-arance as a specimen, but r::uch stronger in oroer that it

woulo resist large forces and survive the full series of tests. By

creating an axial alignment of specimen and test fixture, the benefits of

S)'!Tfl1etry '•lOuld sir.lplify testing. The same colunn size was used for both

fixture and specimen. H01.·1ever, the column of the test fixture was

orientcr:: so that the applied t~nsile force v.Dulc prcY.luce bending about

t1•e strong axis of the fixture. The tension p~ate of t~e fixture \<.'aS '2. 0

in. thick, t•,Jice as much as that of the sr..ecirnen.

3.4 Test Setup

The test \~-as carriei! out using t.."!Je 5-rillion lb. Universal _Testing

: ~achine \\~1ich furnished the requirec1 tensile loading, applie0 at the far

enr1s of the tension flange plate anr~ the fixture tension. plate on a

<Jripning lcr.-c;th of t\·.O feet each. Strains ann deflections Here measured

using electrical resistance \.'ire str<lin rosettes u.nd. linear variable

r, isr-lacc-:n·~nt transforr.;ers (L\~ Is) C'lt rli ffe:rent lcx:c:t.:.cms sl-:a.m in Fig.

469.6

4. The reference roint for r.Jeasuring the relative deflections bet\'.reen

pc)ints a-b and a-c was fixed with respect to the testing machine e<:;>lumns.

Data from strain anG deflection gages 'Nas collected and printed

automatically using a B&F Data Acquisition System at·each loading step.

This saved time \.Jhile eliminating the ever-present rossibility of error

in tra~scription •

. 3.5 Details Qf Specimen (Test i) Test 1 was a control test and it had the most resemblance to one of

the original full-scale connections that fractured during testing. Both

tbe tension flange and ~e flange connection plate had a thickness of 1.0

in. The tension flange plate vms groove-welded to the flange connection

plate using a backing-~ tack~elded parallel to the groove weld at six

different J:oints. The flange connection plate \•las not exactly flush with

the tip of the column fla"lge but projected about 0. 75 in. as sho.om in

Fig. 5. The fillet welds between the flange connection plate and the

column flange had end-- . returns across __ the thickness of the flange

connection plate ~t the tips of the column ~langes. Finally, both

returned welds intersected at top·and bottom of the connection plate (see

Fig. 5) •. '.

4 Test Results

A load-deflection curve of 'rest 1 is given in Fig. 6. Because of

the uncertainty of the final outcome of this first test, load ~~s applied

in many small increments (many more _than the number plotted) • r-.t the enq

of the first day's testing, the specimen was partially unloaded after

having reached about C)J% of the predicted full plastification load.

Testing vms resUJ11ed on the follCMTing day. ~.fter first unloading

completely to pemit adjustment of equirrnent, loading v.-as resumed. At

the tir.Je the indicated load approxir:1ated naninal yield stress across the

entire flange plate, strain qages gave indications of local yielding at

several places on the speci...,en. From that point on, load increased at

nearly const~t slope equivalent to about 0.62 E u~til a sudden fracture

occurred.

The maxinl..lfT'I load occurred at 73'! kips, e(Jllivalent to 73 ksi ultimate

.stress, a'!":Dut 35 percent ':'reater than tr,e nominal yield stress. Fracture

occurred after a fairly extensive elongation over six times the

elongation required for nominal yielr1 of the tension fla11ge, as shawn in

::-i9. 6. The theoretical curve obtained :!:r<:r."\ the elastic-plastic finite

elenent analysis, .conputed up to the yielr': r:oint, is plotted as a dashed

line in the saMe figure. ~Jhiteo.-.rasr had =:.een applied to the specimen in

order to observe fla~ng of mill scale caused by surface yielding of the

specimen. Ho.vever, very little 'vhitewash flal(ing· had been observee ''

before the speciMen ·. faile:1 ahru]:"Jtly with a·· loud noise. A close

inspection of the fractured surface (as sha-m in Fig. 7) revealed that a ,

crack red initiated at one of the outer tack \·lelas and propagated rapidly ..

across the flange tension plate·. Fig. q sho.·IS the trace of the crack

near the outer edge of the backing "bar. The region near the tips of the

column flanges v.ihere fracture had been presumed. to be most probable, \'laS

not L~volved in ~~e fracture.

5 Plans for Re-Testing

Since the fracture Which occurred in Test -1 did not involve the

highly-stressed region between the column flanges, it was .decided to find

if a ronnection which did not have the tack uelds to hold the backing~har

for \velding vJOuld ·perfonn ~s expected. Also it v.>as- desired to see if any

· .~rrrninent cracking had been started in that zone but not observed because

of the premature fracture in -~1e t~nsion plate.

:~o crac-:v:s were ·J.iscovered by the availa"!::::le non-r.estructive testing

rnethC:i'ls. The olr3. groove v.reld, backing-rar, anr'l a slice of the connection

plate 'vere removed hy sawing (to avoid ar:<Cl,ing any ne''' heat effects) and

the sr.>ecirnen vlas prepa.red for re-test by \·leldinq ·on a new 10 by 1 inch

tension :'lance plate. In this case, the ~roove weld was applie:'l using a

':--·2cking-rar tacl:e-3. at t1~e rcot of the \·.'elc, \·ihere the tack "V:elr'ls \•.JOula be

fuse~.l into tre final groove weld.

Since five sr-eci..r.lens had already been •.-.reloed usin0 the unfortunate

r:rra.:1ger.1ent ?f tack \1elc1s, it was necir'i~ to :in(: if the effects of the

tac~..s welcs coult-1 1:-e reducer. by other Means short of replacc.r:1ent 'of the

r.:ntire tension plate anr'l t;rroove welc'l. ?.necir,en !: o:: Tabl•3 l was selected

~ecause it r:-ti(Jht !""'st closely approxirr.1te tr.e cetail of Test 1. The six

tar:}: ,#y.,~l . .:Js \Jere renu;ec1 hy grinding t.~?i tr1 a rencil grin(1€r. This

.•

46c:'.6

rr:oceeure \,.l()Ul.d not remove the residual stresses caused by the welding of

the tack welds, but it could release sene of the local restraint bet'Neen

the reeking l>ar and the nain plates.

3oth of these speciD.ens (Spcci'":'len A re-test a1'1d Specimen B) will be

tested soon, and then furt.l)er decisions \rill be made about the

dispesition of the remaining specirr.cns in the series.

6 Conclusions

The specimen tested sho.·Jed considerable ductilit~ before fracturing.

It reached the expected yield load at about the expected stress. It

reached a ductility ratio ~f about 6. The maximum nor:drial stress of 73

ksi a?Proacr.ea the expec,:ted tensile stress. of the material used.

'1"he fracture at the location of the tack welds \'laS a surprise,

although it should not be unexpected in viE!'N of experiences with fracture

under conditions of fati~e. It should be noted that the backing-bar and

tack welds used \>JOuld be renoved in bridge construction, although they

are frequently left in place in building Construction When they· are used.

The test; . has provided a valuable lesson that \-Je can not be careless about

details involving 'tack welds, even in· statically-loaded construction.

The macroscopic appearance of the fractured surface indicated t.he

existence of plane strain test conditions, hence, a lo.-1 frac;ture

touahness of the specimen, al thoL .. '?h not necessarily of the material.

Crack initiation fran a tack ,.,.eld of a t-acking-bar indicates its

deleterious effect in tensile stress zon~s due to the residual stresses

left behinf!. by \>.relding. Once a crack started in the tension flange

~late, it prona?ated aU the ~-ay tf:rough the plate \·.rithout an ability to

follow a path perpendicular to tr.·e ·theoretical rnaxi.rnum tensile stress

firection, a curved path ·hich \·:as observe<-: in the full-scale connection ·

\·1l1ich fracturecl in the prior test series.

One 2.~r:li tionn.l interesting ol:-scnration may he mane al:x>ut the effects

of ~tep.'"'.rinq specimens as \·Jas done in this series. There is a noticable

i1ifference ir. the nature of residual stresses in the tension plate of the

Namely, vJhile residual

.strl]sses at t}~e tip of rolle:l. "!---ec.J·;, fla'1r.es are cor:lpressive stresses,

4G9.G

L~ose of the tension plate are tensile stresses because of heat cutting.

'!'his introduces high stresses which may exhaust sane of the ductility and

nay be considered responsible for crack initiation in the flange tension

plate. It appears that there are certainly more things to be learned

fran this test program.

. .

46~.6

7 ACKNa'li..EIX;El1ENTs<

This investigation was connucted in the Fritz Engineering Lahoratory

of Lehigh University, Bethlehe.r:1, Pennsylvania. Dr. L. S. Beedle is

oirector of the laboratory. ·The study of the fracture of· ,,reb 111Cl'1ent

connections is s{:X)nsore:-1 jointly ~)y the American Iron and Steel Institute

and the National Science Foundation. Research work is carried out under

the tec1m.ical guidance of an ~.ISI Task Force, of '\..Jtrich ttr. \':alter

Fleischer is chainnan. The interest, encouragement and guida'l"lce of this

committee is gratefully ac~~vledged.

4G9.G

Tit~s. F~or.. Tf. CotJtJ, IZ. STIFF ENE!( SPECIMEN THICKNESS THICKNESS 'THtCKHE5S

;JO. ( '"·) ( 1/J.) (IN.)

A J[tJ CO!'JT/?ot.. t j TE~i

B J[tJ liXT!!'JDEO 1 1 Co"'.rJECriDN

P'IITE

]U:J TAP£1?.!0 1 1 c (o!J,JEC. rrotJ

PUIT6

D J(tJ 11#11/1/tLDEI) t t ~8· -COW /'Ill

/AlES

£ J[O II t 1 rs.

[[D CcJNTRol. T'EST 1 t 1 .A2 WIT II 1:-IICI!.- UP

srtFFEtiER.

52 O(D 1. 1 1

C2 DOl 1 1 j

D.2 J[tJ IJITHOIIt' . 1 t~ BAU<- uP

'57'tFfE/'I€R ·

E2 ](D WITH() liT t 1 ~8 EAO<.- UP

S7tf F c IJ€R.

Table 1 : Test Sr-ecinen Configurations

469.6

-·

~ 6.7!i. Cf.o . -1'---· -/------./

-- --1(-- ,,

!i-0 {' I--·/

. (C)

't'' (. I--- -f-. --

. (B)

h

v 6 .1!i 7· 0 i 6. 0" I, 1 '· >. > • l 1 -1

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':s f--- - ---7-- - - -. -- ---1 ,,

1 5.o J I-

(D)

-

(E)

I

(F) 'I

6. 75 0-75' 8. 25 If f;' I'J

! 6.7:; :.:·.o, 6. o

¥

/~ g -

·/ ~-r-.:----t I ~ \

_I I I

( -f .

'5.0 /---

f5. ,, ~

II

I - - ~ - --·

(G)

Figure 1: rinensions of COnnection Details -~~alyzed

1 .....

-- . -

-·/-l 5.() .

. -jL.

45c:'.6

Test J-ixture ·

Simulated Beam Flange

Umnect<on PlAte Lpecimen

C)

.o·

Figure 2: Test Setup

13

·--- Col,umrt

Welded fnd Plate

0 (J

0 0 C)

()

0

0

,0 0

c

0

c

Reusable Bolted 'Jointng PLare_.

hj .....

~ w .. rn rt 1-1 m Ul Ul I

;I) r+ 1-1 C'J .....

·-~ ::l ·-·-"

() c ~ " ro 0 t-ta·

Ill

g ·§.

:::1 .-:] rD Ul rt

LOAD (Krr:s) ·

100.0

C{o.o

80.0

70.0

60.0

5o.n

40.0

30-0

:zo.o

10.0

o.o o.o

A572 GR11DE 50

1/VtcRIIGE cRoSS

5 t:CTf{VJ 1'1 'A't-// = /. 504 (in~)

S TllrtC YIELD

5TRES5 ·-= 52.7 ( ksi)

ULTIH/11~ 51"'RES5-:= 63.6 (J<si)

o.oo5 o. 0/ -o.o/5 Q.O;J.O

jb

I /f'3o I

zg ~'t

I

I

I

I .3 2. . ~IL, I lc

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.

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TOP VJ£·W

I "31 1"-32.

33

SOcJ Ttf

•a I

..

I

36 3~ .:.-..---------l . ~ 34.

1~...-----__ ~ I

BOTTOM 1/(EW

Figure 4: Layout of !"losettes

469.6

D21/i1L -A

·--~ l>

A

' \ ;\\

!

0.75 II

I I ! I

I i ! I

I \.

Figure 5: Connection Plate iield :Jetai.ls

45~.6

f. 2

/.0

0.6

r I

I

o.4 1

I I I I I

o.z 1

o.o

. ' - - ·--

--- ··-:-·-·- .. ·-"--

t:O 2.0 3.0 4·0 5.0

Figure 6: Load-Displacer,ent CUrve of Test 1

l7

46S'.6

. ..,

;

Figure 7: Front Vie\·,'S · of Fracturco Surface

,,

I ~cl c6i

1 ,< 1 ~--·------~

of'.C .-< !NCT- BAR '··-, '·-----

T/ICKJVELD

~----~, ----~ /0.0 .

Figure 8: Location o= Fracture

....

46?.6

l'Jnerican Helding Society ·1 S80 Steel • Volume Fourth EG i tion: S'!'RUC'I'UPJIJ... \'7El.DI:JG CODE • .P-.rnerican

Helaing ~..ociety Bathe, Y. J., \·li lson, E. L., a11d Iding, R. H. 1974

~:o:::sJl.P ·- A STRUCTUR;-.L l':::rALYSIS Pr-OGPNl FOR STJl..TIC li.:ID DYNAMIC P£SFO!·~SE OF LILJF'AR SYsrEI~S. SEst-·1 Rep:>rt 74-3, University of California, Berkeley •

Driscoll, G.C. 1979 FRACTURES OF BEl'J-'1-'IC-cOI.DMN ·uEB l'O.'Jn~ ca~~CTIOUS •. Fritz Engineering

Laboratory Report 405.10, Lehigh University. Rentschler, G.P., Chen, 'tJ.F., Driscoll, G.C. 1980

TESTS OF B'Ell.J-~-'!'0-car...u~--rri vmB. t·OID'l'I' CONNJX'TIOHS. Ar:lerican Society of Civil Engineers Proceedings, 106(ST5):1005-1022. · Fritz Engineering Laboratory Rep::>rt No. 405.7.

Shen, Shi-Zhao, and Driscoll, c. C. 198la PARAr-1EI'RIC .A.NALYSIS OF TEJ~1'SIOU FI.A":-JGE CONI:TECTIOU DETAILS. Fritz

Engineering LaJ::ora-tory Re:r:ort 469.3, Lehigh University. Shen, Shi-Zhao, Pourrohloul, Abbas, Haist, Pandall· ~1., and Driscoll,

George c. 198lb EI.J\STIC-PI../>.STIC ANALYSIS OF m:SION FIA.~GE CONNECI'ION DETAILS. Fritz

Engineering LaJ::oratory Rerort 459.4, r..ehigh University.