Residual Stresses in Welded Shapes of Flame-cut Plates in Astm a5

7/28/2019 Residual Stresses in Welded Shapes of Flame-cut Plates in Astm a5

1/52

Lehigh University

Lehigh Preserve

Fritz Laboratory Reports Civil and Environmental Engineering

1-1-1969

Residual stresses in welded shapes of ame-cutplates in astm a572(50) steel

Y. KishimaG. Alpsten

L. Tall

Follow this and additional works at: hp://preserve.lehigh.edu/engr-civil-environmental-fritz-lab-reports

is Technical Report is brought to you for free and open access by the Civil and Environmental Engineering at Lehigh Preserve. It has been accepted

for inclusion in Fritz Laboratory Reports by an authorized administrator of Lehigh Preserve. For more information, please contact

[email protected].

Recommended CitationKishima, Y.; Alpsten, G.; and Tall, L., "Residual stresses in welded shapes of ame-cut plates in astm a572(50) steel" (1969).FritzLaboratory Reports. Paper 1907.hp://preserve.lehigh.edu/engr-civil-environmental-fritz-lab-reports/1907
http://preserve.lehigh.edu/?utm_source=preserve.lehigh.edu%2Fengr-civil-environmental-fritz-lab-reports%2F1907&utm_medium=PDF&utm_campaign=PDFCoverPageshttp://preserve.lehigh.edu/engr-civil-environmental-fritz-lab-reports?utm_source=preserve.lehigh.edu%2Fengr-civil-environmental-fritz-lab-reports%2F1907&utm_medium=PDF&utm_campaign=PDFCoverPageshttp://preserve.lehigh.edu/engr-civil-environmental?utm_source=preserve.lehigh.edu%2Fengr-civil-environmental-fritz-lab-reports%2F1907&utm_medium=PDF&utm_campaign=PDFCoverPageshttp://preserve.lehigh.edu/engr-civil-environmental-fritz-lab-reports?utm_source=preserve.lehigh.edu%2Fengr-civil-environmental-fritz-lab-reports%2F1907&utm_medium=PDF&utm_campaign=PDFCoverPageshttp://preserve.lehigh.edu/engr-civil-environmental-fritz-lab-reports?utm_source=preserve.lehigh.edu%2Fengr-civil-environmental-fritz-lab-reports%2F1907&utm_medium=PDF&utm_campaign=PDFCoverPagesmailto:[email protected]:[email protected]://preserve.lehigh.edu/engr-civil-environmental-fritz-lab-reports/1907?utm_source=preserve.lehigh.edu%2Fengr-civil-environmental-fritz-lab-reports%2F1907&utm_medium=PDF&utm_campaign=PDFCoverPagesmailto:[email protected]://preserve.lehigh.edu/engr-civil-environmental-fritz-lab-reports/1907?utm_source=preserve.lehigh.edu%2Fengr-civil-environmental-fritz-lab-reports%2F1907&utm_medium=PDF&utm_campaign=PDFCoverPageshttp://preserve.lehigh.edu/engr-civil-environmental-fritz-lab-reports?utm_source=preserve.lehigh.edu%2Fengr-civil-environmental-fritz-lab-reports%2F1907&utm_medium=PDF&utm_campaign=PDFCoverPageshttp://preserve.lehigh.edu/engr-civil-environmental-fritz-lab-reports?utm_source=preserve.lehigh.edu%2Fengr-civil-environmental-fritz-lab-reports%2F1907&utm_medium=PDF&utm_campaign=PDFCoverPageshttp://preserve.lehigh.edu/engr-civil-environmental?utm_source=preserve.lehigh.edu%2Fengr-civil-environmental-fritz-lab-reports%2F1907&utm_medium=PDF&utm_campaign=PDFCoverPageshttp://preserve.lehigh.edu/engr-civil-environmental-fritz-lab-reports?utm_source=preserve.lehigh.edu%2Fengr-civil-environmental-fritz-lab-reports%2F1907&utm_medium=PDF&utm_campaign=PDFCoverPageshttp://preserve.lehigh.edu/?utm_source=preserve.lehigh.edu%2Fengr-civil-environmental-fritz-lab-reports%2F1907&utm_medium=PDF&utm_campaign=PDFCoverPages


2/52

Welded Columns and Flame-Cut P l ~ t e s

RESIDUAL STRESSES IN WELDED SHAPESOF FLAME-CUT PLATES IN ASTM A572(50) STEEL

by

Yoshio K ishimaGoran A. Alpsten

andLambert Tal l

This work has been ca r r i ed out as a pa r t o f ani nves t iga t ion sponsored by th e American I ronand Stee l I n s t i t u t e .

Fr i t z Enginee ri ng Labor at oryDepartment of Civ i l EngineeringLehigh Univers i tyBethlehem, PennsylvaniaJune 1969

Fr i tz Engineer in g Labo ra to ry Report No. 321.2


3/52

321. 2

TABLE OF CONTENTS

ABSTRACT

1. INTRODUCTION 11 .1 Purpose and Scope 11 .2 Manufacture and Fabrica t ion 21 .3 Background Informat ion on Residual

St ress Studies 3

2. DESCRIPTION OF TESTS2.1 Tension Specimen Tes t s2.2 Res idua l S t re s s'Measu remen ts

3. TEST RESULTS3.1 Tension Specimen Test Resul t s3.2 Residual S tresse s in AsManufactured Pla t e s3.3 Residual S tresse s in WeldedH-Shapes

4. DISCUSSION OF RESULTS

5. SUMMARY

6. NOMENCLATURE

7. ACKNOWLEDGEMENTS

8. TABLES AND FIGURES

9 . REFERENCES

556

10101113

15

18

20

21

23

47


4/52

321.2

ABSTRACT

This r epo r t descr ibes the r e su l t obta inedfrom an inves t iga t ion in to the magnitude andd i s t r i bu t i on o f res idua l s t r e s s in H-shapes weldedfrom f l ame-cu t p l a t e s , as well as in the componentloose p l a t e s . Residual s t r e s s m e a s u r ~ ~ e n t s weremade in two welded H-shapes , 12H79 anQ 14H202,made of ASTM A572 (Grade 50) s t e e l . The method ofsect ioning was used fo r the de te rm ination ofres idua l s t r e s s d i s t r i bu t i on .

The r e su l t s show t h a t very high t ens i l eres idua l s t r e s ses ex is t a t th e port ion n e ~ r ~ h ef lange t i p s and a t th e w eb -to -f la ng e junct lon pa r t s .They a re caused by f lame-cut t ing and by welding .These t ens i l e s t r e s ses a re balanced by a lmostuniformly d i s t r i bu t ed compressive s t r e s s e s in th eremaining pa r t s of the c ro ss sec t ion .

A comparison of the r e su l t s o b t ~ i n e d onthe members of A572(50) s t e e l and previous r e su l t s


5/52

321.2

fo r s imi la r pla te s and shapes of A36 s t e e l i nd ica test ha t the y ie ld s t r e s s o f the mater ia l has prac t i c a l l yno e f f e c t on the magnitude and d i s t r i bu t ion of res idua ls t r e s ses .


6/52

321. 2

1. INTRODUCTION

-1

1 .1 Purpose and ScopeThe purpose o f th e o v er al l i nv e st ig a ti on

i s to s tudy the s t r eng th and behavior o f s t e e lcolumns welded from f l ame-cu t p l a t e s . This phasewas concerned with the magnitude and th e d i s t r i bu t i ono f res idua l s t r e s s in medium s i ze w eld ed H -sh ap esmanufac tured from f lame-cut p la t e s o f ASTM A572(Grade 50) s t e e l . (1)

Two d i f f e r e n t column shapes a reinves t iga ted in t h i s r epo r t , a 12H79 and a 14H202shape*. The dimensions o f these shapes a re shownin Fig. 1. Resu l t s of r e s i dua l s t r e s s measurementson these two shapes a re p re se nte d and a comparisoni s made with the r e su l t s obta ined on the same shapeso f A36 s t e e l . (2 )

Welded f l ame-cu t shapes a re expected tohave a favorab le d i s t r i bu t ion o f r e s i dua l s t r e s sf:-:'r column s t reng th , because o f th-"'- h ~ ~ J h i npu tduring th e f lame -c u tti ng p ro c es s, which i n t roduces*"H" des igna tes a welded H-shape, "/-hile "'VJr" i s fo ra ro l l ed wide-f lange shape.


7/52

321.2 -2

t e n s i l e r e s i d u a l s t r e s ~ e s a t t h e p l a t e edges. Theset e n s i l e r e s i d u a l s tr e s s e s w i l l remain a f t e r weldingt h e p la te s i n to a shape, a l though t h e magnitude o ft h e s t r e s s e s may be somewhat lowered. The d i s t r i b u t i o ni s " fa v o r a b l e " , s i n c e t h e t e n s i l e s t r e s s a t t h ef lange t i p improve column s t r e n g t h .

1 . 2 Manufacture and F a b r i c a t i o nDuring t h e manufactur ing and f a b r i c a t i o n

p r o c e s s e s f o r welding t h e shapes , t h e m a t e r i a l i ss u b j e c t e d t o v a r i o u s h e a t i n p u ts which w i l l producer e s i d u a l s t r e s s e s i n the. c r o s s s e c t i o n . The f i r s th e a t i n p u t t h a t a f f e c t s t h e r e s i d u a l s t r e s sd i s t r i b u t i o n i s t h e r o l l i n g o f p l a t e s . Thet empera ture o f t h e p l a t e dur ing r o l l i n g i s about2,400F. The r o l l i n g i n t r o d u c e s compressiver e s i d u a l s t r e s s e s a t t h e p l a t e edges and t e n s i l er e s i d u a l s t r e s s e s a t t h e c e n t e r of t h e p l a t e . Thesecond high h e a t i n p u t i s during t h e f l a m e - c u t t i n go f p l a t e s , when h e a t i s a p p l i e d l o c a l l y t o t h e p l a t e .The f l a m e - c u t t i n g c r e a t e s t e n s i l e r e s i d u a l s t r e s salong t h e p l a t e edges , being balanced by compress ives t r e s s e s elsewhere i n t h e p l a t e ; t h e s e s t r e s s e s a r esuperimposed on those due t o r o l l i n g . F i n a l l y , t h ewelding o f t h e f l ame-cut p l a t e s t o form t h e shape


8/52

321.2 -3

c a u s e s a d d i t i o n a l r e s i d u a l s t r e s s e s . Very hight e n s i l e s tr e s s e s a r e formed i n t h e weld r e g i o nand compressive s t r e s s e s e l s e w h e r e . The magnitudeo f t e n s i l e r e s i d u a l s t r e s s due t o welding r e a c h e st h e y i e l d s t r e s s o f t h e m a t e r i a l , a s compared t ot h e s t r e s s e s i n r o l l e d medium s i z e w i d e - f l a n g eshapes which a r e much s m a l l e r t h a n t h e y i e l d s t r e s so f t h e p a r e n t m a t e r i a l .

I; Background I n f o r m a t i o n on R e s i d u a l S t r e s s S t u d i e sP r e v i o u s s t u d i e s i n to r e s i d u a l s t r e s s

d i s t r i b u t i o n s i n welded f la m e -c u t w i d e - f la n g e shapesshow t h a t t h e s e shapes have high t e n s i l e r e s i d u a ls t r e s s e s a t f l a n g e t i p s and i n t h e v i c i n i t y o f welds . (2 ,3)The p a t t e r n o f r e s i d u a l s t r e s s d i s t r i b u t i o n i s faundt n be l e s s dependent on t h e m a t e r i ~ l , when 36 k s is t e e l i s compared w i t h 50 k s i s t e e l . The major f a c t o rt h a t i n f l u e n c e s t h e r e s i d u a l s t r e s s p a t t e r n i s t h egeometry o f t h e c r o s s s e c t i o n ; t h i c k n e s s o f f l a n g e andweb p l a t e s , width o f f l a n g e , and t h e d e p t h o f s h a p e . (4)

Res idua l s t r e s s e s i n two welded s h a r e s o fA36 s t e e l were i n v e s t i g a t e d i n t h e e 3 ~ l i e ~ phase o ft h e r e s e a r c h program. (2) The two s h a F ~ s s t u d i e d were


9/52

321.2

12H79 and 14H202 which were fabr ica ted from f lamecu t p la t e s . The r e su l t s obtained on A36 s t e e l i sincluded in th i s r epor t for a comparison with theone on AS72(SO) s t e e l .

-4


10/52

321.2 -5

2. DESCRIPTION OF TESTS

Two types of exper iments were ca r r ied out ;t ens ion specimen t e s t s to determine the mechanicalproper t i e s of th e mater i a l used , and r e s i dua l s t r e s smeasurements to f ind the magnitude and thed i s t r i bu t ion of res idua l s t r e s s e s in f l ame-cu t p l a t e sand H-shapes fabr ica ted from these p l a t e s .

2.1 Tension Specimen TestsTension t e s t specimens were cu t both from

shapes and t h e i r component loose pla te s fo r the14H202 shape, and only from th e shape i t s e l f fo r th e12H79 shape. The loca t ion of these specimens in thecross sec t ion are shown in Fig . 2 with the dimensionsof these specimens , and one in the column shapes a regiven in Fig . 3. Test ing machines used fo r thetens ion specimen t e s t s a re a mechanical t e s t i ng machineof 120 kip c&pacity fo r the 12H79 specimens , and ahydraul ic type machine o f 300 kip capaci ty fa r the14H202 specimens. The r e su l t s inc lude obta inedcomplete s t r e s s - s t r a i n curves drawn by an automat icrecorder . The data were eva lua ted fo r s t a t i c yie ld


11/52

321. 2 -6

s t r e s s (a ys )' s t r a i n a t the onse t o f s t r a i n

hardening ( e s t ) ' s t r a in -harden ing modulus (Es t ) 'u l t imate t ens i l e s t r e s s (a ) , pe rcen t e longa t ion inu8 inch gage l eng th , and percen t reduc t ion of a rea .

The number of t ens ion specimens t e s tedfrom th e v ar io us members i s shown in Table 1 .

2.2 Residual St re s s MeasurementsFor th e d ete rm i na tio n of the magnitude

and the d i s t r i bu t i on of r e s i dua l s t r e s s , the methodo f s ec ti on in g( S,6 ) was adopted using a Whittemoremechanical s t r a in gage with a 10 inch gage l eng th ,which i s shown in Fig . 4 toge ther with th e milds t e e l bar fo r th e temperature compensation.

The number of s pecimen s u se d fo rr e s i dua l s t r e s s measurement i s given in Table 1.The loca t ion of the specimens in th e f ab r ica ted columnmembers a re shown in Fig . 3. The d is tance from theend of the member to these sec t ions was chosen to bea t l e a s t one' and a ha l f t imes the l a rges t l i nea rdimension of the cross sec t ion . Thus, th e s t r e s se xis t in g in a long member was conta ined in th e t e s tspecimen. (5)


12/52

321. 2 -7

The method o f s ec t i o i i ng r equ i res atl e a s t two measurements of each gage l eng th ; oncebefore sec t ion ing , and then a f t e r sec t ion ing th especimen i n to s t r i p s . Fur thermore , in t h i s s tudy ,one a dd it io na l s te p was inc luded, which i s ca l l ed"pa r t i a l sec t ion ing" . This i s an i n t e rmed ia t e s t epbefore complete sec t ion ing as shown in Fig . 5.A smal le r number o f long i tud ina l cu t t i ng s a re madefo r the pa r t i a l sec t ion ing (Fig. 5b) than fo rcomplete sec t ion ing , which i s th e f i n a l s t ep asshown in Fig . 5c. The purpose o f t h i s in te rmedia tes tep i s to have an approximate idea o f th e r e s i dua ls t r e s s d i s t r i bu t i on and a l so to see if th e numberof sec t ions can be reduced in fu tu re t e s t s .

Thus , r e f e r r r i ng to Fig . 5 j the s tepso f re s idua l s t r e s s measurements are as fo l lows:

1 . Prepa ra t ion of gage holes and l ayou to f sec t ion ing l i ne s on th e specimen.

2. I n i t i a l read ings .3. Transverse cu t t i ng . (Fig. Sa)4. Pa r t i a l s ec t i on ing . (Fig. 5b)5. Readings a f t e r p a r t i a l s ec t i on ing .6 . Complete s ec t i on ing . (Fig. 5c)


13/52

321. 2

7. Fina l read ings .

To evaluate r e s i dua l s t r e s s fromWhi tt emore g ag e r ead ings , th e fol lowing formulawas used.

-8

(x.1where,

cr . = r e s i dua l s t r e s s o f the s t r i p i,rlE = modulus o f e l a s t i c i t y ,L = gage l eng th ,B. = average o f the i n i t i a l readings on the1

s t r i p i,Ref.B. = average o f re fe re nc e bar read in gs fo r1

th e s t r i p i before sec t ion ing ,A. = average reading on th e s t r i p i a f t e r1

sec t ion ing ,Ref.A. = average of r e fe rence ba r read ings fo r1

th e s t r i p i a f t e r sec t ion ing .

Deta i l s of th e s ec tio nin g a re shown inFigs . 6 and 7 fo r the 12879 and 148202 shapes ,

' r e spec t i ve ly . The loca t ion of cu ts fo r th e pa r t i a lsec t ion ing i s also ind ica ted in Fig . 7 fo r th e shape


14/52

3 2 1 . 2

14H202. F o r th e c o m p o n e n t loose p l a t e s of the14H202 s h a p e , Fig . 8 shows de t a i l s o f the pa r t i a la nd c o m p l e t e se ct io nin g o f we b ( F i g . 8a) a n df l a n g e ( F i g . 8b) l o o s e p l a t e s .

-9


15/52

321.2 -10

3. TEST RESULTS

3 .1 Tension Specimen Test R esu ltsThe r e su l t s obt ianed from tens ion

specimen t e s t s are summarized in Table 2. Theda ta inc lude s t a t i c y ie ld s t r e s s (cr s t )' ul t imatete n si le s tr es s (cr ) , modulus o f e l a s t i c i t y (E) ,us t ra in-hardening modulus (Es t ) ' s t r a in a t theonse t o f s t ra in-hardening ( e s t ) ' p er ce n t e lo n ga tio nin 8 inch gage l eng th , and pe rcen t redu ction of area .Mechanical proper t i e s o f the mater i a l as spec i f i edby the ASTM S tanda rd (De signat ion A572-66) (1 ) areyie ld s t r e s s , t ens i l e s t reng th , and e longa t ion in8 inch gage length . The proper t i e s of the mate r i a lused s a t i s f i ed the ASTM requi rements fo r A572(Grade 50 ) s t e e l .

As can be seen from the values o f percen te longa t ion in an 8 inch gage l ength and of pe rcen tr educ t i ono f ' a r e a as wel l as from th e spec i f ica t ion ,t h i s low al loy high s t r eng th s t e e l has a f a i r l y goodduc t i l i t y .


16/52

321. 2 -11

Average s t r e s s - s t r a i n c urv es u sin g th eaverage va lues of these data (E, a ys ' Es t ' and Est)are shown in Fig . 9 fo r both shapes . The curve fo rthe l4H202 shape shows a more gradua l o f f s e t frome l a s t i c range , a lower s t a t i c y ie ld s t r e s s , and anea r l i e r onse t of s t r a in -harden ing than the one fo rthe l2H79 shape. This could be due to the geometr ice f f e c t (see Fig . 2 fo r the dimensions of t ens iont e s t specimens) and due to smal l r e s i d u ~ l s t r e s s e sl e f t in th e l a rge r specimens cu t from the l4H202shape and from i t s component p l a t e s .

3.2 Residual S tresses in As-Manufactured Pla tesResidual s t r e s s measurements were ca r r ied

out on th ree loose pla te s taken from the same paren tp la t e as the component pla te s of the l4H202 shape;one web p la t e (4D, 12 5/8" x 15/16") 3.nd -twc f langepla te s (4E and 4F, 15 3/4" x 1 1 /2" ) .

Residual s tr e s s d is tr ib u ti on s obta inedon these pla te s a re shown in Figs . 10, 11, and 12.Figure lOa shows the d i s t r i bu t i on of r e s i dua l s t r e s sobtained on th e web p la t e (4D) a fte r p a r ti a lsect ioning and Fig . lab the one a f t e r 80mplete


17/52

321.2 -12

sec t ioning . For th e f la nge loose p la t e s (4E and4F), s imi la r diagrams are given in Figs . 11 and 12.

Comparing the diagrams correspondingto pa r t i a l sec t ion ing and complete sect ioning onthese th ree loose p l a t e s , it i s noted t h a t thepa r t i a l sec t ion ing procedure gives a good i nd ica t iono f the a ctu al r es id ua l s t r e s s d i s t r i bu t i on , a l thoughonly two cuts were made on each p l a t e . Since th enumber of cuts and the number o f measurements necessaryfo r the pa r t i a l sect ioning i s fa r l e s s than what i sre qu ire d fo r the complete sect ioning procedure , t h i ssugges t s a s impler method to obta in an es t imate o f th er e s i dua l s t r e s ses by t ak ing the s tep in between thesetwo s t eps .

Cons id er ab ly h igh t ens i l e res idua l s t r e s sex i s t s a t the f lame-cut edges of th e p l a t e s . Theset ens i l e s t r e s ~ e s are balanced by an a lmosi u n i f o ~ mcompressive res idua l s t r e s s elsewhere in the p l a t e .Some i r r egu l a r i t y i s observed in the d i s t r i bu t i onof r e s i dua l s t r e s s a t the edges of the f lange p la t e4E a f t e r complete sect ioning as i s seen in Fig . l Ib .For t h i s p l a t e , the re appears to be a s teep s t r e s sgrad ien t across the p la t e th ickness a t the edges .


18/52

321.2 - l ~

3.3 Residual S tre sses in Welded H-Shapes

Residual s t r e s s measurements were ca r r iedout also on welded H-shapes o f two d if fe re n t s iz es ,12H79 and 14H202.

Residual s t r e s s d i s t r i bu t i ons obta inedon th ree i den t i ca l sec t ions of 12H79 shape are shownin Figs . 13a, b , and c . As i s seen in these diagrams,there ex i s t very high t ens i l e re s idua l s t r e s ses inthe welds and also high t ens i l e r es id u al s tr es se 3 a tthe f lange t i p s which are due to t he f lamecu tti ng ofp l a t e s . Compressive re s idua l s t r e s ses are r a t he runiformly d i s t r i bu t ed elsewhere in the ~ e c t i o h toallow equilib rium of the cross sec t ion . Althoughthere i s some i r r egu la r i t y in the upper r i gh t f langein Fig. 13b, the pa t te rn of r e s i d u ~ l s t r e s sd i s t r i bu t i on i s bas ica l ly the same in a l l t h reesec t ions . Since these th re e s ec tio ns were cu tor ig ina l ly from one long member, it can be notedt ha t res idua l s t r e s s d i s t r ibu t ion i s cons tan t alongthe leng th of the member.

For the shape 14H202 of A572(50) s t ee l ,res idua l s t r e s s d i s t r i bu t i ons a re shown in Figs . 14a


19/52

321.2 -14

and b. These two sec t ions were cu t from the samemater i a l . The tendency o f the d i s t r i bu t i on i smore or l e s s s im ila r to th e one in 12H79 shape.The main d iffe re nc e in the d i s t r i bu t i on of res idua ls t r e s s e s in these two shapes i s t h a t the h ighes tcompressive res idua l s t r e s s i s on the o uts id e surfaceo f the f lange a t th e web-to-f lange junct ion in14H202 shape, whi le in 12H79 shape t h i s i s in t ens ion .


20/52

321.2 -15

4. DISCUSSION OF RESULTS

Summarizing the re s idua l s t re s sd i s t r i bu t i on in the component loose pla tes o f th el4H202 shape o f A572(50) s t e e l , Fig . 15 shows th eaverage d i s t r i bu t i on in the loose web p l a t e (4D).For the d ia gram , a ve ra ge va lues a re obta ined fromthe s t r e s ses on both su r faces o f the p l a t e . Theaverage t ens i l e re s idua l s t r e s s a t th e f l ame-cu tedge i s 43 ks i and the compressive re s idua l s t r e s sin the mid-por t ion o f th e p l a t e i s approximately4 ks i . These va lues correspond to 0.8 cr and 0.07yscr , re spec t ive ly , where cr i s the s t a t i c yie ldys yss t r e s s obta ined from tens ion t e s t s and i s equal to55.0 ks i for" the web loose p la t e .

For the f lang e lo ose p l a t e s (4E and 4F),the s imi la r diagram i s shown in Fig . 16. The averaget ens i l e re s idua l s t r e s s a t the p l a t e edge i s 25 k s iand the compressive s t r e s s in mid-por t ion i sapproximate ly 3 ks i . They a re 0.5 cr ys and 0.06 cr ys 're spec t ive ly , where the s t a t i c y ie ld s t r e s s obta ined


21/52

321.2 -16

from t ens ion specimen t e s t s i s equa l to 53.0 ks i fo rthe f lange loose p l a t e s .

As fo r the r e s i dua l s t r e s s d i s t r i bu t i onin the welded H-shapes bui l t -up from f l ame-cu tp l a t e s , Fig . 17 shows th e average d i s t r i bu t i on inthe 12H79 shape of A572(50) s t e e l toge ther with theone in A36 s t e e l . Average s t r e s s e s are ca lcu la t edby t ak ing one ha l f of a f lange and one ha l f o f aweb as un i t s . That i s , each po in t in the f langer ep resen t s the average of 24 s t r e s s e s , and the onein th e web r ep resen t s 12 s t r e s s e s measured. Theaverage t ens i l e s t r e s s fo r the A572(50) s t e e l shapei s 15 ks i a t the f lange t ip and 43 ks i a t th e weld , .which correspond to 0.3 a and 0.8 a , r e s p e c t i v e l y ,ys ysth e average s t a t i c y ie ld s t r e s s (a ) being 55.8 ks i .ysThe res idua l s t r e s s in th e m id -p or tio n of the flangei s approximate ly 15 ks i in compression, and th e onein m id-portion of th e web i s about 4 ks i in t ens ion ,t ha t i s , 0.3 a and 0.06 a , r e s pec t i v e ly .ys ys

A ~ may be seen in Fig . 17, the r e s i dua ls t r e s s d i s t r i bu t i on i s very s im ila r in both typesof s t e e l and so i s the magnitude of r e s i dua l s t r e s ses .This impl ies t ha t the type of s t e e l does not grea t lya f f e c t the magnitude and the d i s t r i bu t i on of res idua l s t r e s s


22/52

321. 2 -17

For the 14H202 shape, the average r e s i dua ls t r e s s d i s t r i bu t ions in the members o f both A572(50)and A36 s t ee l s are shown in Fig . 18. Again theaverage s t re sses are computed on the bas i s of oneha l f f lange and one ha l f web.

The res idua l s t r e s s d i s t r i bu t ion i svery s imi l a r to the one in 12H79 shape, and thepa t t e rn i s s imi la r fo r both A572(50) and A36 s t e e l s .For the shape o f A572(50) s t e e l , the average t ens i l er es idua l s t r e s s e s a re 20 k s i a t th e f lange t i p , and27 ks i a t the web-to-f lange junct ion pa r t . Sincethe average s t a t i c y ie ld s t r e s s determined from 't ens ion specimen t e s t s i s 54 ks i , they are 0.4 a. , . . ysand 0.5 a ys ' respec t ive ly . The compressive res idua ls t r e s s i s approximately 13 k s i in the mid-por t iono f the f lange and 4 ks i in th e mid -p or tio n o f theweb, which correspond to 0 .2 a and 0.08 ays ys ,r espec t ive ly .


23/52

321.2 -18

5. SUMMARY

This r epo r t descr ibes th e r e su l t s ofres idua l s t r e s s measurements in two welded H-shapesmanufactured from f l ame-cu t pla te s of A572 (Grade 50)s t e e l as wel l in t he i r component f l ame-cu t p l a t e s .This i s one phase of an ove ra l l gene ra l i nves t iga t ionin to the s t r eng th and behavior o f columns weldedfrom f lame-cut p la t e s .

The conclusions deduced from thesemeasurements are the fol lowing:

1 . Very high t ens i l e residual . s t r e s s e s ex i s t inth e reg io ns close to th e f lange t i p s ,d i rec t l y as a r e su l t of the f lame-cu t t i ng .

2. Very high t ens i l e res idua l s t r e s s e salso ex i s t in the v i c in i t y of the webto - f l ange junct ions , due to welding.

3. Compressive res idua l s t re sses arer a the r uniformly d i s t i i bu t ed in f langesand in the mid-por t ion o f web. Themagnitude o f compressive res idua l s t r e s s


24/52

321. 2 -19

i s more uniform in th e smal le rshape (12H79) than in the l a rge rshape ( l4H202) .

4. Residual s t r e s s d i s t r i bu t i on in thec ro ss s ec tio n i s cons tan t along theleng th of the s t e e l members.

5. Comparing th e r e s i dua l s t r e s s e s inA572 (50) s t e e l with A36 s t e e l , th ey ie ld s t r e s s has a lmost no e f f e c t onth e magnitude and on the d i s t r i bu t i onof res idua l s t r e s s .The major fac to r t h a t governs theres idua l s t r e s s i s th e geometry o fthe cross sec t ion .

7. Comparing th e two shapes o f A572(50) s t e e l , the magnitude o f r e s i dua ls t r e s s , both in ten sion and incompress ion , i s grea t e r in the sm alle rshape (l2H79) than in the l a rge r shape(l4H202) .


25/52

321.2 -20

6. NOMENCLATURE

A.1

Ref.X.1

B.1

Ref.B.1

EEs tFCHLWF s tcr .rl

"cryskipsk s i

Average read ings o f th e gage l engthi a f t e r sec t ion ing .Average o f re fe rence ba r read ingsfo r the s t r i p i a f t e r seo t ion ing .Average read ings o f th e gage l engthi before sec t ion ing .Average o f re fe ren ce ba r read ings fo rth e s t r i p i before sec t ion ing .Modulus o f e l a s t i c i t y .Stra in-hardening modulus.Flame-cu t .Welded wide- f l ange shape .Gage l eng th .Rol led wide- f l ange shape .St ra in a t th e onse t o f s t r a in -harden ing .Res idual s t r e s s o f the s t r i p i (pos i t ivefo r t ens i l e and negat ive fo r compressiver e s idua l s t r e s s ) .Ult imate t e n s i l e s t r e s s .Sta t i c y ie ld s t r e s s .One thousand pounds .One thousand pounds per square inch .


26/52

321.2 -21

7. ACKNOWLEDGEMENTS

The i n v e s t i g a t i o n was conducted a tF r i t z Engineering Labora tory , Lehigh U n i v e r s i t y ,Bethlehem, Pennsylvania , and was sponsored by t h eAmerican I r o n and S t e e l I n s t i t u t e . Lynn S. Beedlei s t h e D i r e c t o r o f t h e Laboratory and David A.VanHorn i s t h e Chairman o f t h e C i v i l Engineer ingDepartment.

The t e c h n i c a l guidance made by t h e memberso f Task Group 1 o f t h e Column Resea rc h Cou nc il u nde rt h e chairmanship o f John A. G i l l i g a n i s g r a t e f u l l ya p p r e c i a t e d .

The a u t h o r s owe s p e c i a l thanks t o t h e i rr e s e a rc h c o ll ea g u e s a t F r i t z Engineering Laboratoryf o r t h e i r a s s i s t a n c e f o r t h e r e s e a r c h , e s p e c i a l l yt o Ching-Kuo Yu and Jacques B r o z z e t t i .

Apprecia t ion i s a l s o due Kenneth R. Harpel ,l a b foreman, and h i s s t a f f f o r t h e i r c o o p e r a t i o n i nconduct ing t h e t e s t s .


27/52

321.2

The authors wish to express t h e i rs in ce re a pp re cia tio n to Richard N. Sopko fo r h isf ine work on th e photographs , to John M. Geraand h is s t a f f fo r a l l drawings , and to MissJoanne Mies fo r he r typew ri ting o f the en t i r emanuscr ip t .

-22


28/52

321.2 -23

8. TABLES AND FIGURES


29/52

321.2 -24

Table 1 NUMBER OF SPECIMENS

Test Member l2H79 l4H202

Tension Shape l2-Flange 3-FlangeTest 3-Web I-WebLoose 6-FlangePla te 0 Pla te2-Web

Pla te

Residual Shape 3 2St ressMeasure- Loose 2-Flangement Pla te 0 Pla teI-Web

Pla te


30/52

321. 2Table 2 Tension Sepcimen T est R esu lts

-25

Static Modulus Strain* Strain- ... ElongationShape Specimen Yield of Ultimate at Strain- Hardening in 8in. Reductionor No. Stress Elasticity Stress Hardening Modulus Gage Length of AreaPlate (ksi) (103 ksi) (ksi) (%) (ksi) (%) (%)3AI 55.3 29.9 85.6 - - 24.8 45.03A2 57.2 29.7 85.8 1.10 748 25.6 48.93A4 54.0 31.2 82.8 1.05 698 26.5 50.33A5 54.8 28.6 82.6 1.14 710 25.8 52.4

Shape 381 55.5 28.7 84.9 1.07 691 26.0 47.912H79 382 56.7 20.4 85.0 1.58 411** 25.3 47.9(Flange) 384 54.2 29.8 84.4 1.00 676 25.3 47.7385 54.9 29.5 82.6 1.12 685 26.4 51.33CI 56.7 30.2 86.1 0.80 712 23.9 46.63C2 56.7 28.6 85.6 1.01 728 24.5 46.83C4 57.1 28.8 86.9 0.86 777 22.3 44.93C5 57.3 28.4 87.2 0.90 758 20.5 44.8

Flange Average 55.9 - 85.0 1.06 719 24.7 47.9Shape 3A3 56.5 30.8 74.6 1.83 436 22.8 46.112H79 383 54.6 18.2 78.2 - - 27.1 48.1(Web) 3C3 55.6 28.0 73.2 1.97 506 25.8 48.8

Web Average 55.6 -- 75.4 1.90 471 25.2 47.7Average -t- 55.8 -- 82.7 1.25 662 24.8 47.9

Shape 481 55:-3 22.3 86.5 - 823 26.5 56.514H202 482 55.1 28.5 86.6 0.86 859 27.0 56.8(Web) 483 55.0 27.0 86.0 -- 840 23.8 40.7

4EI 51.4 29.3 83.6 0.63 771 27.2 58.8Flange 4E2 52.4 29.3 83.7 0.67 836 26.7 58.7Loose 4E3 52.6 28.2 84.7 0.63 839 26.6 56.8Plate 4FI 53.9 29.7 84.4 0.50 836 27.8 58.1

4F2 - 26.4 85.0 0.53 808 26.9 57.04F3 54.5 30.2 85.1 0.44 849 26.5 56.6

Flange Average 53.8 - 85.1 0.61 829 26.6 55.614H202 484 54.0 -- 80.8 1.04 723 26.9 56.6(Web)

Web 401 54.7 28.8 84.5 0.76 796 22.6 49.3LoosePlate 402 55.3 29.5 84.2 0.72 714 23.6 50.1Web Average 54.7 - - 83.2 0.84 744 24.4 52.0Average -t- 54.0 -- 84.7 0.65 811 26.1 54.8

*" Estimated from load -elongation diagrams drawn by an automatic recorder.* * Omitted when averaging-t Weighted average


31/52

321. 2

l-r'--- 12 ---i-1\r------------. . . , I

\ , II~ ~ / 2 1234l"

-26

I I 12H79

rt------ 15 3/4" - - - - - - - I ~ ~ II' L --,1\/2

f15t II16 5 II15 Va

14H202

Fig . 1 Dimensions of the Shapes Studied


32/52

321. 2 -27I

I

:::--- ~ : : f - - -- - ~ ' t - - - 14H202

12H79I I I I

Flange Plate !~ r : m t m~ " " , - - - d p " - - - -II

Web Plate !lTIill....._ . ~ _ - - - III

II- 8 t

1.5 11,...------,or-------or------,.-1 t

T

12H79 14H 202Flange Web Flange Web3 II 1/2

II 1 1/2 II 15/ ..t /4 16

F ig . 2 Locat ion of Tension Tes t Specimens in Cross Sec t ions


33/52

3 2 1 . 2

12H79

14H202

- 2 8

I::===rlt======

[EI:::::::::=:====I ~ IS",!8" 11 1I 26 1-9 111 ~ ---3---=0=--=--'----=11-------:1]1:::::::::=:===1 ['t 11-S"31- 6 11 11 11 221-10 11-1:- -I.. ..I f-I.-----------l=lI-- 301-0 11 -l

" I ~ ~ 9 i ,'I. 10'-0111_ 14'-011FlangePlates [EL...----I{

:1

Web Plate

[ ] < - - - - _ I ~ Ir-III-. - - - - = - - 1 4 . . . : . . . - ~ - ~ I . : : : . . ; ~ _ 11__

1

Fig . 3

r:7/l Specimens for Residual StressI::'LLl MeasurementsII] Tension Specimens

L a y o u t of Tes t S p e c i m e n s


34/52

321. 2 -29

Fig . 4 Whit temore St ra in Gage


35/52

321. 2

( a) TransverseCutting

(b) PartialSectioning

CompleteSectioning

-30

Fig. 5 Sect ion ing Steps


36/52

321. 2 -31

- ~ -~@ ~m C\J

=

3@i ~ 4 . ~ ' 1 3 t 8 1r-

--

3@~ I ~ I I ~ I I7tS..-.1l 16

-j I IfFig . 6 Sect ion ing Deta i l s fo r 12H79 Shapes


37/52

321. 2

II I I

I I " 1./ I II I-too-- - -f - -

Saw Cuts ...-...-~f - - -f - - -f - - -f--~~~~f--~~~~~~~r-----,-- c-- - -

I ....I / " I II I II I I

-32

~ @oC\I

Fig . 7 Sect ioning Deta i l s fo r l4H202 Shapes


38/52

321. 2

II .. 31 "4 @ '2 '8t -I I '"

12 5/8 "(a) Web Plate (40)

(b) Flange Plates (4E and 4F)

-33

Fig . 8 sec t ion ing Deta i l s fo r Pla tes


39/52

STRESS(KS!)

80

o

, . - - - - . . . ; ; ; ; ; ; ; ; ; ; . , , ; ~ - = ; . . . . ; ~ - -55.8 ksi54.0 ksi

5STRAIN

10

WN.......N

Fig. 9 Average St re s s -S t r a i n Curves Obtained fromTension Specimen Tests - - A572(Grade 50) Stee l ILV.l:>o


40/52

321. 2 -35

-10 c s ~ : ~ : t ~ . ~ :o.w.C:JKSI 010203040 (a) After Partial Sectioning50

(b) After Complete Sectioning

-10KSI o L ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~

10203040

50

Fig. 10 Residual S tress D is tr ibu tio n in Web Pla te : 4D


41/52

321. 2 -36

Saw Cut

(a ) After Partial Sectioning

(Saw Cut

-20- 10 I

I~ ' 8 8 ' & ! Q 8 ~ ' ~ ~ ~KSI O I - - - - e - _ + - - - - - - - - - : : . - ~ - " ' - ~ ~ - - - = - - " " - - t - - ' 1 i - - - + - -10203040

( b) After Complete Sectioning

-20-10

KSI o U - I J . ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ h -102030405060

Plate 15 3/4 1/ x I 1/2 1/ (FC), A572 ( 50)Fig. 11 Residual S tr es s D i str ib u ti on in Flange Pla te : 4E


42/52

321. 2 -37

(a) After Partial Sectioning

Saw Cut(saw Cut-20-10

KSI 0 ~ - 4 - ~ 5 ~ ~ ~ ~ ~ ~ ~ ~ g ~ r 10

(b) After Complete Sectioning

-20-10

KSI o h Y - - ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~10

Fig. 12 Residual S tr es s D i st ri bu ti on in Flange Pla te : 4F


43/52

321. 2-40-20

KSI

406080

80

-20-40

IN.024I I I

-38

9? 0- Near Surface Far Surface

(a)

Fig. 13 Residual S tre ss D is tr ib ut io n in 12H79 (Fe)Shape, A572(50) Stee l


44/52

3 2 1 . 2-40-20

KSI O ~ ~ - - + O - - + - - + - - - - + " "20406080

I

IN.024I I I

- 3 9

~ Near Surface Far Sur face

KSI20 0 -20

I I

80604020

KSI 0-20-40

(b)

F i g . 13 R e s i d u a l S tr es s D i st ri bu ti on in 12H79 (FC)S h a p e , A572 (50) Stee l ( C o n t i n u e d )


45/52

- 4 0

------0- Near Surface Far Surface

I

IN.o 2 4I I I

3 2 1 . 2

-40-20

KSI 020406080

r I"lIIll ,..

806040

(c)

Fig. 13 R e s i d u a l S t r e s s Dis t r ibu t ion in 12H79 (FC)S h a p e , A572 (50) S tee l ( C o n t i n u e d )


46/52

3 2 1 . 2

5 060708090 ---0---0--- Near Surface---- Far Surface

- 4 1

I90807060SO

14H202(FC)AS72(SO)

(a )

F i g . 14 R e s i d u a l S tre ss D is tr ib ut io n in 14H202 (Fe)S h a p e , A572( 50) Stee l


47/52

3 2 1 . 2 -42

5060708 0 --.0- Near Surface

Far Surface

. I

( b)

14H202(FC)A572(50)

KSII 70 60 50 40 30 20 10 0 -10 -20- ---------.J

I9080

F i g . 14 R e s i d u a l S tre ss D is tr ib utio n in 14H202 (FC)S h a p e , A572 (50) Stee l ( C o n t i n u e d )


48/52

321. 2 -43

-10

10

20

KS I O I - - _ F - - . . . . . . . l o L . . - - - - - - - - - - - - - ~ -

30

40

50

Fig . 15 Average Residual S t re ss D i s tr ib u ti on inWeb Pla t e (4D), A572(50) Stee l


49/52

321. 2

-10

~ fl. 4E fl. 4F

-44

40

3 II I IIFlange Plate, 15 14 x I V2 ,Fe

Fig . 16 Average Residual S tr es s D i str ib u ti on inFlange Pla t e s (4E and 4F) , A572(50) Stee l


50/52

321. 2

-30-20

--0--0-- A572 (50) A36KSI 0

10

20304050

-45

IN.o I 2 3I

Fig. 17

12 H79 (Fe)

Average Residual St ress Dis t r ibu t ion in12H79 (FC) Shape


51/52

321. 2

-2 0

-0---0- A572(50).............. A36

-46

IN.o I 2 3 14H202 (Fe)I 1 I I

Fig. 18 Average Res idual S tr es s D i str ib u tio n in14H202 (Fe) Shape


52/52

321.2 -47

9. REFERENCES

1. American Socie ty fo r Test ing and Mater ia l sSTANDARD SPECIFICATION FOR HIGHSTRENGTH LOW-ALLOY COLUMBIUMVANADIUM STEELS OF STRUCTURALQUALITY, ASTM Designat ion A572-66,ASTM Standards , Pa r t 4, January 1969.2. McFalls, R. K. and Tal l , L.A STUDY OF WELDED COLUMNS MANUFACTURED

FROM FLAME-CUT PLATES, The WeldingJourna l , Vol. 48, Apr i l 1969.3. Tal l , L.WELDED BUILT-UP COLUMNS, Fr i t zEng ineer ing Labora to ry Report No. 249.29,

Apr i l 1 9 6 6 ~4. Alpsten , G. A.RESIDUAL STRESSES IN HEAVY WELDED SHAPES,Fr i t z Eng inee ring Laboratory ReportNo. 337.12, January 1969.5. Huber, A. W. and Beedle, L. S.RESIDUAL STRESS AND THE COMPRESSIVESTRENGTH OF STEEL, The Welding Journal ,Vol. 33, No. 12, December 1954.6. Tebedge, N.MEASUREMENT OF RESIDUAL STRESSES A STUDY OF METHODS, M.S. Thes is ,Lehigh Univers i ty , May 1969.

Documents

Residual Stresses in Welded Shapes of Flame-cut Plates in Astm a5