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ON

WELDED REINFORCEMENT OF OPENINGSIN STRUCTuR& STEEL MEMBERs

BY

D. VM4~Y1 .4N0 B. A. EECBTMAN

UnfvrtnityofWasbiiM >UnderBureauofSb& ContractNObs-60238

(JndexN..NS.Zil.034)

M~RB LIBRARY

SHIP STRUCTURE COMMITTEEihlvcaedby

ThesecretaryoftbeTreasmy

W“lla..0, S“WP,..

A,Da”. cam-.x... m.W”xr.”,

*MI*m.u=r””. COISM,TT,.

“. . . C. AS, .U,no “...@”.-”.

W*.”! ”.70N *S. . . . .

mcmfBERl&M51 ,.

SHIP STRUCTURE COMMITTEE

MEMBER AGENCIES: December15, 1951 ADDRESS CORRESPONDENCETo:

~.”,.. 0, S“,,’, D..,. e, NAVV sscmm.”v

Mlu,,.” s..7..,s,0 .,,,,.,s,.”,.., D,n. 0, M.,, s“,, s,.”., ”,. co..,,,,,.

UNITE.S,ArcsCOASTG.,.., TREAS.”” D,rr, U, S. Cc..,, GUAR. H, A.. ”AR, ERS

MARITI.K A. MtNIST..T, ON, m.,. w co..c.cm WASH,..,.. ,s,D. c,Au,.,.,. BuRn” 0, S“,,,,?+.

Mar Sir:

.

Herewithis a COPXof the firstProgressReporton the investigationof ‘tWeldedRehforoeraentof Cpeni.ngsin StructuralSteelMembers(tby D. Va8arhelyiand R. A.Hechtman. This investigationie beingconductedat theUniversityof Washingtcafor the Ship StructureCommitteeand cover8the work completedto August1950.

ky questions,comments,criticismor othermatterspertainingto the Reportshouldbe addressedto the Secretary,ShipStructureCcmuaittee.

This Reportis beingdistributedto thoseindividualsend agenciesassociatedwithand intereetadin the work of the Ship StructureConm!ittee.

Yourssincerely,

%c-K. K. COWARTRearAdmiral,U. S. CoastGuard’Chairman,Ship Structore

Ccmaittee

. ..$

. PREFACE

‘TheNavyDepartmentthrought~ Bureauof Ships is distributingthlereportfor the SRIP STRUCTURECOMMITTEE.tl$thoseagenciesand individuslewho were act!velyassociatedwith theresearchwor~. Th.iereportrspre-eenteresultsof part of the reeearchprogramconductedunderthe ShipStructureCommittee*sdirsctiwiOto tmpro~ the hull at,ficturesof Ehipsby an e%tensitin@ kflowled@petitainfngto deeign,materialsand mekhodeof fabrication.n

,-.

The 4$etributionof this reportisas follows:

Sh$p StructureComu&ttee

Copy No. 1 - RearAdmiralK. K. Cowart,LECG- Cheinuancopy No. 2 - Rear AdmiralR* L. Hicke,USN, (Ret.) MaritimeAdministrationCopy No. 3 - RearAdmiralE. W. Sylvester,LSN,Bureauof Shipscopy No. ~ - Capt.W. N. Manefield,t5NRjMilitarySea TransportationServiceCopy No. 5- D. P. Brown,AmericanBureauof Shipping

Ship StructureSubcommittee.

Copy No. 6- Capt.E. A. Wright,lSN,BWSSU of Ships - ChairmanCopy No. 7 - Comdr.E. A. Grantham,TEN,MlllterySea TransportationSertice

* c Opy NC* 8 - Comdr.D. B. Henderson,lBCG,U. S. CosetGuardHeadquartersCOPY No. 9 - Lt. Comdr.M. N. P. Hinkamp,~N, Bureauof Shipe “cOpy No. 10 - Lt. Corn&.E: L. Perry,LECG,U. S. CoastGuardI%adqusrtarsCopy No. 11 - W. G. Frederick;MaritimeAdsinietrationCopy No. L2 - HubertKempel,MilitarySea TransportationServiceCopy No. 13 - J. b!.Crowley,Officeof NatilResearchCopy No. L$ - M. J. Letich,AmericanBureauof Shippingcopy NO. ~ - L. C. Host,AmericanBureauof ShippingCOPY No. f6 - E. M. MacCutcheon,Jr., Bureauof ShipeCopy No. 17 - V. L. RUSSO, MaritimeAdmlnlstrstionCopy No. 18 -.Finn Jonsseen,’LiaieonRepresentative,NRCCopy No. 19 - E. H. Dsvidson,LiaisonRepresentative,AISIcopy No. 20 - l?.P. Gerhart,LiaieonRepresentative,AISICopy No. 21 - Wm. Spraragen,LiaiaonRepresentative,WRCcopy No. 22 - CharlesHoch,Milita~ Sea TransportationSertice,Alternate

MemberCOpY No. 23 - W. E. Megee,U. S. CoastGuard,AlternateMembercopy Ho. 2.4- J. B. Robertson,‘Jr.,U. S: CoastGuard,AlternateMemberCOpY No, 25 - John Vasta,Bureauof SHipS,AlternateMasher

* COPY No. 26 - J. E. Walker,Bmeau Qf Shfps,AlternateMemberCOPY No. 27 - EdwardWenk,David.Ta$lorModelBaein,AlternateMember

\ .

-li -

U. s.,Aqly-,.,..,

Copy No. 28..WatertownArsenal@o@tory,.,

,.. U..S. Navy

:Attn:S. V. &llO~

CopyNo. 29 - Chief,Bureauof.Stips,NavyDepartmentcopy No. 30 - Capt.R. H. hmbqrt, tSN,PhiladelphiaNavalShipyardCopy No. 31 - Capt.C. M. ‘Tooke,lEN,”Long BeachNavalShipyardcOPY No. 32 - Comdr.H. G. Bowen,lSN,CodeRe-3,Bureauof ordnanceCopy No.B - Comdr.R. S. ,kndelkorn,lSN,PortsmouthNavalShipyardCopy No. 34 - A. Amirikfan, Bureauof Yardsand DocksCopy No. 35 - A. G. BisselJ,Bureauof ShipsCopy No. 36- JosephBrock,DavidTaylorModelBasinCopy No. 37 - J. W. dmkins,...BYOaU Of ShiPS.COpy No. 38 - Carl Hartbower,.,NavalResearchI+boratoryCopy No. 39 - NoahKahn,Ney York NavalShipys+

,,.,,Copy No. .@ - A. S. !!arthenp,Bureauof Ships.copy No. 1+1- 0. T. Marske%Na@ .Research.LaboratoryCopy No. 42 - J. E. McCembridge,IndustrialTestingLsb.,Pbila.Naval

>,.,.~,,.;:..-shipyardCOPY No. 43 - W. E. McKenzie,MetallurgicalBranch,NavalGun Factorycopy No. 44 -:WiLLiS@. ,,?e&l.ipi,Metallur~ Divn.,Na@ Resesrohkboratoq

.,:,GopyNo..,L5T N,E, Pro@gel,,Bvreauof AeronauticsCopy No. 46,F NavalRes.e@chLaboratorycopy No. 47 - Nav@,RepearchLaboratory,MechanicalSectioncopy No. 48 - NavalResearchLaboratory,MetallurgicalSectioncOpy No. .?+9- Post GraduateSchool,U.,S. NavslAcademyCopiesNo. 50 and 51 - U. S. NavalEngineeringExperimentSectionCopy No. 52 - New York NavalShipyard,““lhterial,LaboratoryCopy No..53 - IndustrialTeetingLaboratoryCopy No. 54 - PhiladelphiaNavalShipyardCopy No. 55 - San FranciscqNavelShi~rd b

COPY No. 56 - DsvidTaylorModelBasin,Attn:,.LibraryCopiesNo. 57 a~d 5’8- TechuicalLibrary,Bureauof Shipe,Code 3$4

U. S. CoastGuard

COW, NO. 59 - Capt.R. ~’.Lank,Jr., LSCGCOpy NO. 60 - Capt.H. C. Moore$L6CGCOpy No. 61 - Capt.G. A. Tyler,WCGCopy No. 62 - Testingand Development,Division .#

COPY No. 63 - Il.S. CoastGuardAcademy,New London

U. S..AkritimeAdmln3str@ion ..

Copy No. @ - ViceA&. E. L. Cochrane,lSN (Ret.)COpy No. 65 - E. E. Martinsky

.

.

●

.

*

*

C*tt09,, on ShipSteel.

Cow. No. 66- P. E. Kyle,- ChairmanCopyL’No.67- C. H. Herty,“Jr.- ~ce CbairnBI” ‘“‘2

.,, .

copy No. 68.

- Wm. M. Baldwin,Jr.CO~y NO. 69 - C. S. Barr5~~Copy No. 7C - R. M. BrickCoPy No. 71- S. L. HoytCopy No. 13 - J. M. Crow16y ““cOpY NO.. 72 ; k W. LightnercOpy No. 73 -’R. F.”Mebl ,..,,

Copy No. 74 - T. S. Washburn ““Copy NO. 18 - Finn Jonassen- TechnicalDirectorCopy No. 75 - A. Mull.er- Consultant

..::,:Membersof‘“P$jeot~d~sory CommitteesSR-9$,SR-99,SR-lCO,SR-108,SR-1C9,SR-ll~;andSR-Lll(notlistedelsewhere)

copy“lb.76+. R. ‘Hp”’’AbOin ““ ,. .,.,.Copy NOm’77,Q’E~”A. Anderson’‘ ,“, ‘ ,(,““”,:,:,“.... ...

COpy NO. 78 - L; C. BibberCopy..No. 79 -:,MorrisCohen

,..:.,

Copy ITo;8b -W. C. Ellis’ “: ‘,’::.,,;‘“’::> ‘ -““’”’:”’”:: “COPY NO. ?31- M. Gen=+mercopy No. @’ -

.,...;.. + . ..‘M.,F:’&Wk~~”;”) : ,’ “Copy }10..83- W: F- ~&W’’”’” ,“copy No.,~”- W.‘R.+b+rd; .Jr. .;‘:.,COPY N0.:85- C’;E. ‘Jackson ,Copy No. 86 : J. R.,”,L+;jJro: “’“’2,’;;],”Copy NO. ~’,.-,H.W. P16rce ::Copy No. 88 -~W. A. Reich ~ :“”~’”,,’:,,.,COpy No.’,89’-’C.E. Sims ,. ,’.

., ,’,.,.COPY No. 9CI,-’R.~. StOUt ‘“ ? ,’““”” :: , ,copy NO. 91’- J. G. Thompson ,,

COPY NO. 92,,

- B. G. Johnston,WeldingRese@ch’Goticil,L~isonCOPY No. 93 - w. H. wooding,Philadelphia‘Nat+s,$tierd

.:. .

.,,

.,. - .,

copy Ko. 94 -copy NO. 68 -Copy No. 95 -Copy No. % -Copy No. 97 -COpy NO. 98 -Copy NO. 18 -

Committeeon Re$~d# “St$e&& ‘. “, ,.,.

J. T. Notin - Chaitin’:~ .“,’,,.’.’,,.~Wm. M. Baldwin,Jr. “’ ,“ .:j, ~,Paul FfieldLeVanGrlffieK; HeindLhoferIkmlelRosent~lFinn Jonsssen“-TeohnicalDirector

,..

-fv -

Representativeeof AmeficanIron end StielInstituteCommitteeon MenufncturlngProblems

Copy No. 99 - C. M. Parker,Secretary,GeneralTechnicalCdttee, A.ISIcopy No. .% - L. C. Bibber,U. S. SteelCQ.COpY No. 67 - k?. H. Herty,Jr.,BethlehemSteelCo. ‘“Copy No. 100 - E. C. Szdth,RepublicSteelCorp.

CoPy No. 101 - C. A.Copy No. 102 - Harry

WeldingResearchCouncil

Adams Copy No. U33 - LaMotteGroverBoardman Cow.,Ho. 21 - Wm. Spraragen

copy No. 104 - w. w.

Copy N0.,105.- C. R.RubeY.ChairmaniNationalReeearchCounoilSode~&rg, Chaib, DIv.Engineeringf+Ind@trial

‘“Research,NRCCopy No. 18 - Finn Jonassen,TechnicalDirector;Committee,on Ship SteelCOpy Nc. 106 - R. A. Hechtmen,Investigator,ResearchprojectSR-119Copy No. 107 - S. T. Carpenter,Investigator,Reeearch.~oj~cts SR-98and

SR-3.18Copy No. 68 - Wm. M. Baldwin,Jr.,Investigaticr,ResearchProjects.?R-99

and SR-111COpy }1..108 - C. R Vcldrich,Investigator,Resesroh@eject SR-1OOCopy Nc. 109 - P. J. Rieppel,Investigator,ReeearchProjectSR-1OOCopy No. 110 - M. L. Williams,Investigator,ResearchProjectSR-106Copy No. 111 - C. A. Ellinger,Investigator,Researchno jectSR-106Copy No. 73 - R. F. Mebl,Investigator,ResearchProjectSR.108Copy No. 70 - R. M. Brick,Investigator,ResearchPrcject..SR-109Copy No. 11.2- C. H. Lorig,Investigator,ResearchPrcject.SR-11O.Copy No. 113 - E. W. Suppiger,Investigator,Research.ProjectS~-~3Copy No. Ill+- CerloRiparbelli,Investigator,Research,PrcjectSR-113COPY No. 28 - S. V. Arnold,Investigator,ResearchProjectSR-114Copy No. 17 - V. L. Russo,Investigator,ReeearchProject,SR-.ll7Copy No. 115 - G.,S. Mikha.lapov,Investigator,ResearchProjectSR-~0CopiesNo. 116 and 117 - Army Air MaterialCommand,?right.FieldCOPY Nc. 3.18- ClarenceAltenburger,GreatLakesSteelCo.Copy No. 119 - J. G. Althouse,LukenaSteelCo.copy No. 120 - T. N. Arzstrong,The InternationalNickelCo., Inc.Copy No. 121 - R. Archibald,Bureauof PublicRoadsCopy No. 122 - F. Baron,NorthwesternUniversityCopy No. 323 - BritishshipbuildingResearchAssoc.,Attn: S.L Asher,Sac.Copy No. 124 - J. P. Comatock,NewportNexeShipbuilding& DrydockCo.Copy No. 125 - A. J. Durelli,ArmourResearchFoundation,,~OpyNo. 126 - W. J. Eney,FritzEng. Lab.,LehighUniversityCopy No. 127 - S. Epstein,BethlehemSteelCo.CCPY Nc. 1.28- J. H. Evens,MassachusettsInstituteof TechnologyCopy No. 129 - A. E. Flanigan,Universityof CaliforniaCopy No. 130 - L. E. Grinter,IllinoisInstituteof Technology

.

●

-T-.

copy No. 131 - W. J. Htis, Jr.,ldetillurgisalAdvlsoryBowl, .~,

COPY No. 132 - T. R. Higgl.ne,AmericanInstituteof SteelConetruct~on.CopieeNo. 133 thro~h 157 - E. G. Hill,BritishJointServlceaNlesion,

(NavyStaff) .,copy No. 158 - 0. J. Horger,TimkenRollerBearingCo.COPY No. 159 - L. R Jaokson,~ttells Mmrial Inetitut@ ~~ ~ ~~copy Ho. 160 - B. J. Johnefmn,Udversity of MichiganCOpy NO. 161 - J. Jones,BethlehemSteelCo.Copy No. 162 - K. V. King,StandardOil Co. of Californiacopy No. 163 - E. P. Kller,Universityof Lk+rylendCopy No. 164+- W. J. Krefeld,ColumbiaUniversityCopy l?o.165 - J. B. Letherbury,New York ShipbuildingCO.copy No. 166 - E. V. Lewi~,GeorgeG. SharpCopy No. 167 - C. W. MacGregor,MassachusettsInstituteof Technology ~‘:”copy No. I@ - R. C. Madden,KaiserCo., Inc. .,

COpy No. 169 - G. M. Magee,Associationof AmericanRailroads “ I ““Copy No. 170 - J. H. M@@~ld, BethlehemSteelCo., ShipbuildingDiv.Copy No. 171 - NACA,Ak*n: MaterialsResearchCordination,Navy Dept.Copy No. 172 - N. M. Newmark,UniversityCFIlli?oiaCopy No. 173 - CharlesH. Norris,MassachusettsInstituteof TechnologyCopy No. 174 - E. Orowan,MassachusettsInstituteof TechnologycOpy No. 175 - W. G. Perry,RN, BritishJointSertioesMission(NavyStaff)Copy No. 176 - WalterRsmberg,NationalBureauof StemierdsCopy No. 177 - L. J. R&l, U. S. SteelCo.cOpy No. 178 - W. P. Roop,SwarthmoreCollegeConv N.. 179 - H. A. Schede.‘Univarsit!?of Californiar.

c OPY N& 180 - SaylorSnyde~,U. S. St~elC o.cOpy No. 181 - E. G. Stewart,StandardOil Co. of N. J.Copy No. 182 - R. G. Sturm,PurdueUniversityCopy No. 183 - K. C. Thornton,The AmaricanShipbuildingCo.Copy No. 184 -Copy No. 185 -copy No. 186 -COPY No. 187 -copy No. 188 -Copy No. 189 -Copy No. 190 -Copy No. 191 -COpy No. 192 -CopiesNo. 193copy No. 198 -cOpy No. 199 -CopiesNo. 200 through-204 - Bureauof ShipsCopy No. 205 - L. Crawford,Investigator,ResearchProjectsR-I.21COPY No. 206- ~. c . r. 3cG, ld~,COpy No. 207 -

12//$”/5/~ 4.

COpy No. 208 -& .2++ Ia.ft 5/.3-f

@ ~- ). T ~ 1=/,~/~1COpy No. 209 - C++-. Q.T. 7, Tflfi /~/~Y/r/

A. R. Troisno,”Case Instituteof TechnologyR. W. Vanderbeck,U. S. SteelCo.T. T. Watson,LukensSteelCo.Webb Instituteof NavelArchitectureGeorgesWelter,EcolePolytechnlqueInstituteG.W inter,CornellUniversityL. T. Wyly,PurdusUnlversl~Divisionof Metallurgy,NationalBureau of StandardsTransportationCorpsBoard,Brooklyn,N. Y.through197- Libraryof Congressvia Bureauof Ships,Code 324C. A. Zapffe, Carl A. Zapffe LaboratoryFileCopy,Committeeon Ship Steel

-vi-

Copy No. 210 -

%g,K: % :COPy No. 213 -Copy No. 214 -COPY No. 215-Copy No. 216-COpy No. 217 - B.>copy No. 218 - ~ -..copy No. 219 -Copy No. 220 -Copy No. 221 -copyNo. 222 -copy No. 223 -copy NO. Za -COPY No. 225 .

~ P“,-..+ - ‘“- ’-’-L .,..,.:

--wbti *+.., b.@.kw+i% - ~sio.c+ b&&Cw~ _

(Total- 22.5,copies) ,

w -. v,k.~—” icb- \3, l’35~

1

“’I.II.III.IV.

v.

VI.

VII.VIII.

WELDEDREINFORCEMENTOF OPENINGSIN STiWCTURALSTEELMEMtMRS

TAME OF CONTENTS

Contents

Intreduction’ ,.PreviousTheoreticalWorkObjectand Scopeofthe l?.xpertien~IfivestigatiOn i~~Testsand TestMethods1. SpeciqenSteeland Weltig Electrode

Dstaik”of TestSpecimens;: Methodof TestingPlateSpecimens!.+.Gagingand MeasurementsResultsof Tests1.

;:

4.

5.6.

7.8.

Introductionof Definitionof TermsDistributionacrossPlate of Elongationon 36-In.Gage LengthComparisonof Load on Specimen~and Avewge Elongationon

36-In.GageLengthGeneralYieldkg in the PlainPlatesand the Plates

with OpeningsUltimateStrengthof PlainPlatesand Plateswith OpeningsEnergyAbsorptionof thePlainFlatesand the Plateswith

OpeningsEffactivenessof the ReinforcementUnit StrainConcentrationin the Platesin the Region

aroundthe OpeningDeformationand Fractureof Plateswith OpeningsBriefSummaryof the ExperimentalResultsof the Tests

of PlainPlatesand Plateswith Openings

9.10.

Discussionof TestResults1. GeneralYielding,UltimateStrength,andEnergyAbsorption

of PlainPlatesand Plateswith Openings2. Effectivenessof the ReinforcementConclusionsAcknowledgement

AppendixA - Reviewof Referencesin TechnicalLiteratureon Openingsin Plates1. MathematicalAnalysesof Stressesin

2.

3.

Plateswith OpentigsExperimentalDeterminationof btressesinPlat~swithOpeningsBibliography

*

1

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1718

2025

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33373940

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2

LIST OF.TASLES

TableNo.

1

2

3

4

5

6

7

Title P* ‘

MechanicalPropertiesof Platesof DifferentThickness.Sefi-KilledSteelU as Rolled.

Descriptionof Spectienswith’l/4-In.BcdyPlate.

List of PlatesUsed for Fabricationof Each Specimen.

Strengthand EnergyAbsorptionof I/f+-In.PlainPlatesPlateswith Openings.

42”

43

L4

and “, 45

Efficiencyof Plateswith Openingsas ComparedwithPlainPlates. 47

Typesof FleinforcementGivingthe GreatestEfficianciesforPLatesnith OpeningsSustainingCompletelyDuctileFractures. 49

GeneralYieldingati Fracturesof PlateswithOFenings. 50

LIST:O?,FIGURES

Fig. No.

1

2

5

6

7

.

9

10

XL

12

13

u+

. 15

16

Title

hlicrostructuresof TypicalPlatesoffor S“pecti@n5.

,.

Each ThicknessUsed

Detailsof PlainPlatesand PlateswithUnreinforcedOpenings.

Detailsof Piat6swith“Openings

Detailsof~.ates with OpeningsPlate. .

Detailsof Plateswith Openings

Reinforcedby a Face Mr.

Reinforcedby a SingleDoubler

Reinforcedby Sri’InsertPlate.

TypicalSpecimen.Mountedin 2,400;00&1b.Readyfor Testing.

Locationof SR-1+ElectricStrainGagesonUnreinforck+dOpenings.

Locationof SR-~ tilectricStrainGagesonOpeningRei+o reedby a Face Bar.

Locationof SR-LElectricStrainG&es on

TestingMachineand.,,.

Specimenswith

Specimenswith

SDecimenswithOpeningReinforcedby a SingleDoubierPlat~.

Locationof SR-L ElectricSt&iiiGageson Specimens”withOpeningReinforcedby an Ii@ertPlate.

.DistributionacrossPlateof Elongationon 36-in.GageLength.’S@L?c.No. 1. PlainPlate. ,“

DistributionacrossPlateof Elongatiorion 36-in.GageLength. apec.No. 23. PlainPlate. ,,,,

Distributionicros”sPlate of Elongationon 3f+in.GageLength. Spec.No. 2. CircularOpening. Ho FteWorcement.

DistributionacrossPlateof’Elorigationon 36--U.‘GageLength. Spec.No. 3. SquareOpening..lJoFteinforcement.

DistributionacrossPlate of Elongationon 3&in. Gage,Length. Spec.No. 4.~:SquareOpeningwith’RotidedG5fndrs.No Reinforcement. ....,

DistributionacrossPlateof Elongationon 36-in.GageLength. Spec.lJo.5. CircularOpening. Face Bar

~

52

53

53

54

54

55

56

56

57

57

58

58

58

58

59

ReiifOrcem>nt. 59

LIST OF FIGURES

Fig. NO.

17

18

19

20

21

22

23

24

25

26

27

Title

DistributionacrossPlateof Elongationon 3t-in.Gage’‘Length. Spec.No. 6. CircularOpening. Face BarReinforcement.

DistributionacrossPlateof Elongationon 3kin. GageLength. Spec.No. 7. SquareOpening. Face BarReinforcement.

Distribution.,acrcmsPlate of Elongationon 3&in. GageLength. Spec.No. 8. SquareOpening. FaceBarReinforcement.

DistributionacrossPlate of Elongationon 36-in.GageLength. Spec.No. 9. SquareOpeningwith Rounded~~~Corners, Face Bar Reinforcement. .,

DistributionacrossPlateof Elongation.on36-ti.GageLength. Jpec.lio.10. SquareOpeningwikhRoundedCorners. Face Bar Reinforcement.

DistributionacrossPlate of Elongationon 36-in.GageLength. Spec.No. 11. CircularOpening. SfigleDoublerPlateReinforcement;

DistributionacrossPlateof Elongationon 36-in.GageLength. Spec.No. 1.2.CircularOpening. SingleDoublerPlateReinforcement.

DistributionacrossPlateof Elongationon 36-in.GageLength. Spec.No. 13. SquareOpsning. SingleDoublerPlateReinforcement.

DistributionacrossPlateof Elongationon 3.6-in.GageLength. Spec.No. IA. SquareOpening. SingleDoublerPlateReinforcement.

DistributionacrossPlateof Elongationon 36-in.GageLength. Spec.No. 15. SquareOpeningwith RoundedCorners.SingleDoublerPLateReinforcement.

DistributionacrossPlateof Elongationon 36-in.GageLength. Spec.No. 16. SquareOpeningwithRoundadCorners.SingleDoublerPlateReinforcement.

P* ‘

.

59

59

60

60

60

60

J

.

.

.

.

LI.STOF FIGURES

Fig.No. Title ~..

28

29

30

31

32

33

34

35

36

37

38

39

Lo

L1

DistributionacrossPlateof Elongation.on3&in. GageLength.Spec.’No. 17. CircularOpening. InsertPlateReiiforcamerit.

DistributionacrossPbte “ofElongatiofion 36+b’.Gage”“~e&th;.Spec.No. u. CircularOpening. InsertPlate”Reikiforcement.’

DistributionacrossPlate of Elongation“on3&~. .Ga~e”’Lerigth.Spec.No. 19. SquareOper&ng. InsertPlateReinforcement.

DistributionacrossPlate of Elongationon 3&in. ‘dageLet&thi‘Spec.iio.20. SquareOpening. InsertPlateReinforcement.

DistributionacrossPlate of Elongation‘on36-in.GageLength.“.Spec.No. 21. SquareOpeningwith RoundedCorners. InsertPlateReinforcement.

DistributionacrossPlate of Elongationon 36-in.Gage Length.Spec.No. 22. SquareOpeningwith RoMded Corners. InsertPlateReinforcement.

AverageElongationto UltimateLoad and to.Failureon 36-in.Gage Lengthfor PlainPlatesand Platesy+tiiOpenings.

Comparisonof Load and AverageElongation.on 36-in.GageLengthfor P~in Plstes.

Comparisonof Lead and AverageElongationon 36-in. GageLengthfor pl.ates with an UnreinforcedOPefig.

Comparisonof Load and AverageElongationon 36-in.Gage ‘“’Lengthfor PlateswithOpeningsReinforcedby a Face Bar.

Compsrisonof Loadand AverageElongationon 3&in. GageLengthfor PLateswith OpeningsReinforcedby a SingleDoublerPlate. ,.

Comparisonof Load and AverageElongationon 3@in. .GageLengthfor PlateswithOperiingsReinforcedby”an InsertPlate.

Comparisonof UltjmateLoad and AverageElongationto UltimateLoad for PlainPlatesand PlateswithOpenings.”

Load and AverageStresson Net CrossSectionat GeneralYieldingof PlainPlatesand PlateswithOpenings.

62

62

62

63

63

63

6L

65

66

67

68

69

70

71

LfiTOF FIGURES

Iig. No. “Title’ ~

42

43

44

45

46

4’7

48

.49

50

51

52

53

54

55

56

Ulttite Strengthof,PlainPlebes:akd Plateswith Openingsi ‘.72

Comparisonof Ultimatehad andfor Plateswith Openings.

Comparisonof Ulthate Strengthment for Plateswith Openings.

Percentageof Reinforcement

.. ..~> ,.. .

with Percentageof Reinforce-

Relationbetweeathe UltimateStrengthof Plateswith Openingsand the Notch Acuityof the Opening.

EnergyAbsorptionto UltimateLoadand to Failurefor Plateswith Openings. .. .

Comparisonof EnergyAbsorptionto FailureandPercentage“ofReinforcementfor PlateswithOpenings.

Rslationbetweenthe EnergyAbscirpt2ioRto ‘Failureof Elateswith Openingsand the NotchAcuityof the Opening.

Comparisonof the EfficiencieswithRespectto Ultimateloadand EnergyAbsorptionto Failurefor PlateswithOpenings”.

Comparisonof theEfficiencieswitl-”‘Respectto UltimateStrengthand i?,nergyAbsorptionto Failurefor”PlateswithOpenings. ,,,., .,.,,

SketchShowingMethodof‘Presentktitiof UnitStrainConcen-trationin Plateswith Openings.

,.

Unit StrainConcentrationh Regionof Opening.~ -Spec.No. 2CircularOpening. No Reinforcement. .

Unit StrainConcentrationin Regionbf“Opening.Spec.No. 5.CircularOpening. Face Bar Reinforcanent. .

Unit St~n Cdricentrationin RegionOT Opening.” Spec.No. 6.CircularOp&ing. Face Bar Reirifc+c&ient.

Unit StrainConcentrationin Regionof Ope,ning.Spec.No. 11.CircularOpening. SingleDoublerPld,e”~eihforcement:

Unit StrainConcentrationin Regionof Opening. Spec.No. L2.CircularGpening. bingl~DoublerPlate‘Reinforcement.

.

73

74

76

77

78

79

80

81

81

82

82

83

83

.

)

..

.

LISTOF FIGURRS

.Fig. ?40. Title

. 57

58

59

60

61

62

*

63

.

64

65

66

67

68

69

.

70

.71

Unit StrainConcentrationin Regionof-.. . Openiig. Spec.NO. l??.CircularOpening. Insert”PlateHeworcement. ,.

Unit strainConcentrateon in Regionof Opening. Spec.1~0.18.Cifiil.arOpening. ImsertPlateReinforc+meiit.

Unit StrainConcentrationin Regionof Operiing.Spec.No. 4.SquareOpening,RoundedCoiners. No Reinforcement.

Unit strainConcentrationin Regionof Opening. Spec.No. 9.SquareGpening,RoundedCorners. Face Bar .Reinforcement.

:.:

UnitStrainConcentrationin kegionof Opining. Spec.No. 10.SquareOpening,RoundedCorners. Face dar R&nforcsment.“

Unit StrainConeentrationin Regionof Opening. Spec.NO. 15.SquareOpening,RoundedCorners. SingleDoublerP1-steReiO-forcement.

Unit strainconcentrationin Regionof Opening. Spec.No. 16.SquareOpening,RoundedCorners. SingleDoublerPlateRein-forcement.

.,

Unit >trainconcentrationin Regionof Opening. Spec.Na. 21.SquareOpening,RoundedC orriet%,“InsertPlateRe~orc ement.

,.

Unit StrainConcentrationin Regionof Opening. Spec.NO. 22.SquareOpening,RoundedCorners,&m4rt PlateRei~or&ment. ;

Unit StrainConcsntratiOn in Regionof .Op@ng. SPec.NO. 3.SquareOpening,NO Reinforcement..

Unit StrainConcentrationin Regionof Opening. Spec.No. 7.squareOpenfig,Eace Bar Reinforcement.“ ,,

Unit btrainConcentrationin Regionof Opening. Spec.No. 8.Face Bar Reinforcement.

Unit StrainConeentrationin Regionof Opening. Spec.No. 13.squareOw=fig> SingleDOu’OlerplateRei~Orcement.

UnitStrainConcentrationin Regionof Opening. Spec.No. IA.SquareOpening,SingleDoublerPlateReinforcement.

Unit StrainConcentrationin Regionof Opening. Spec.No. 19.SquareOpening. InsertPlatsReinforcement.

P*

w

81+

%5

85

86

%6

w

:87

88

88

’89

89

90

90

91

LIST

Fig. No.

72

73

7L

75

76

77

78

79

80

a

,“

82

83

8L

OF FIGURES

~tle

Regionof Opening..Spec.No. 20.Unit StrainConcentrationinSquareOpening. InsertPlateReinforcement.

HighlyStressedRegionsaroundOpeni+gsof UnreWorced Platesas Indicatedby StresdcoatAnalysis. ThreeShapesof Openings.

Photographsof Rim of OpeningwhichBuckledIater~ly during .Loading. Plateswith DifferentTypesof ReinforcementaroundOpening.

Comparisonof Load and the MaxinumLateralDeflectionof theBuctiledEdge of Openingin Plateswith Openings.

Photographsof PlainPlatssand Plateswith Opekgs afterFracture.

Photographsof PlateswithOpeningsafterFracture.

Photographsof Plateswith OpeningsafterFracture.

Photographsof PlateswithOpeningsafterFracture.

Comparisonof TotalLoad on,Plateand TotalLengthof Fracture.~:

Relationbetweenthe U~timateStrength”and the NotchAcuityofthe Opening,for IllinoisHidePlate Tests. SteelE as Rolled.

Relationbetweenthe UltimateStrengthand the NotchAcuityofthe Openingfor Illinois:{idePlateTests. SteelD as Rolled.

Relationbetweenthe UltimateStrengthand the NotchAcuityofthe Opening,for Illinois,iidePlate Tests. SteelD Normalized.

Relationbetweenthe UltimateStrengthand the Notch~cuityoftheOpening,fpr,,,iidePlateTe,stsby Thomas~and didenburg..“SteelE as rolled.

,!, ., . .

,.,,’

,

91

92

93

9.4

95

96

97

98

99

100

101

102

103

.,,,

.

.

LISTOF FIGUREREFERENCESIN TEXT

(

.

Fig. No.

.&.

2

3

L

5

6

7-1o ~

11-33

3J’+

35-39

40

u

1+2

43-44

45

l@+7

lf!

49-50

51-72

73

74

75

76-79

80

81-84

Referredto on pages

,.&; :,., ,

5, 7, 9, lo

5, 9

5, 9

5, 9, 3$

6

7, 21

10

u

1.2,3-3,U, 25

13

1.4

15, 16

if, 16

16, 34, 36

17

L3, 35, 36

19

20, 22, 26

26, 27, 3L

27

28

29

29

34, 35

LIST OF TABLEREFER31,!CESIN TEXT

TableNo.

1

2

3

4

5

6

7

Referredto on pages

4, 12, lb, 15

5

5

14, 17

18, 19

20, 25

26, 28

.

PROGRESSREPORT

(FIRST)

by

D. Vasarhelyiand R. A. HechtmanUniversityof “I,ashington

for

SHIPSTRUCTUR3COW.;lTTEE

UnderNavy ContractNObe-50238IndexNo. NS731-0311

WF.IDEDREINFORCEMENTOF OPENINGSIN STRUCTURALSTEZLMZMBERS “

4

I. INTRODUCTION. .

.The introductionof an openingwithina structuralmemberis often

.,”necessaryto permitthe passageof conduitor personnel. Theseopeningsweaken

the structuralmemberby decreasingits cross-sectionarea as well as by pro-

ducinga regionof stressconcentration.Variousmethodsof reinforctigsuch

openingshavs beendevelopedin orderto increasethe net cross-sectionarea

of the member,but onlya Littletheoreticalor expertientalinformationis a-

vailableconcerningthe effectivenessof the differenttypesof retiorcement

and the magnitudesof the stressespresentin and aroundthe reinforcement.

The experimentalinvestigationreported hereinhad as its purpose

the determinationof the effectivenessof four typesof arc-weldedrei&?orce-

. ment for openingsin plain-carbonstructuralsteelplatesloadedunderuniform

tension. The openingwae centrallylocatedin eachplateand had a widthequal

to one-fourthof the widthof the plate. The effectof the openingand of the

varioustypesof reinforcementuponthe load at yieldtig,the ultimatestrength,,-

the ductility,and the unit straindistributionin the vicinityof the opening

was investigatedand comparedwith similar

openings.

The testprogramcoveredin thie

observationsfor plateswithout ,

reportis the initialpart of a

largerprogramof tests. Includedin the presdntreportare testsat room

temperatureof two plainplateswithoutopenings,threeplateswith unrein-,

forcedopenings,and eighteenplateswith arc-weldedreinforcementaroundthe

opening. Threetypesof weldedreinforcementwere investigated:face bare,

_\-

“4-

>

singledoublerplates,and insertplates. The plateswithoutreinforcement

and thosewith each typeof reinfo~ementwere fabricatedwith threeclifferent ●

..,.,..

shapesof openings: circular,squ&e with roundedcorners,and equsrewith “‘’“‘, i,.:..,

sharpcorners.-..,..,

Followingthe List of Figuresat thebeginningof this

founda tablegivingthe referencesin the text to eachfigure...

~1. .PREVIOUSTHEORETICALW3RK... ....’ :

.. ...?!.<’r:.!

reportwili tie’““

The presentinvestigationwas prefacedby a somewhatthoroughseArti~‘“.. ,.,.

of the technicalli~rat~e,,for solutionsby the theoryof elasticityof ~hd:““-,,.i.

.. .variouscasesof plates,yithopeningsloadedunderuniformtensionin one

direction. Solutionswere found.fo,r.p&}es of,constantthicknessand “hf”k+~~ ‘““f

widthwith circular,ellipticai~or,pya:loidhple,e,and for a circularhole””~ J~”“’”; .

a plateof constantthic@ess and finitewidth. Solutionswere.,...

platesof constantthicknessand,infinitewidthwith a circular,.,

forcedby a sectionof increasedthicknessaroundthe opening.,,’,.’:

bibliographyof thesereferencesare givenin AppendixA. ‘~

~SO foundfOi:”‘“‘“:

,:,...... ~~~openingrem-

~ ~_ry:&, -:,

The availabletheoreticalsolutionswere onlyqualitativelyapplicable““”

to the typesof reinforcementused in thisprogramof tests. Threeimportcint’

conclusions,,however,were indicatedby the variousmathematicalanalysesof the

elasticstressesin,platesof infinitewidthand c.cnstantthicknesswitii”‘circular”,

openingsreinforcedby an increaseof the plate thicknessinxnediatelyaround

the opening:..’.;:.

1. An increaseof the smou@ of reinforcementdecrecisekthe maxhufm ,,,..;

circumferentialstresson the rim of the opening,but as addition-

al amountsof reinforcementare addedthey becomekcreasingly

-3-

,

.

less effectivein reducingthis circumferentialstress.

2. While the reinforcementdeoreaseethe maximumcircumferential. ... .

etreeseeareundthe opening,it simultaneouslyincreaseethe

raximumshearetreesesadjacentto the reinforcement.This

increasein the maximumcheerstresseerendereit impoeeible

that any reinforcementmay restorethe full strengthpoeeessed

by a pletewithoutan opening.

3. The amovr,tof area addedby the.reinforcementie more effective

in reducingthe circumferentialstressesthe.qthe b?~i.ng ~‘

stiffnessof the reinforcement.

R. Emerimentaldatawere fOmd in the literaturewhichwere “‘

directlyapplicable$0 thisproblem.

III. OBJECTAND SCOPEOF THE EXPERIMENTALINVESTIGATION

The experimental’”programof teetewas plannedprimarilyto find

informationusefulfor the developmentof“designcodesfor structural

memberswith reinforcedopeningewherearc-meldingwas the methndof

fastening. The objectof the investigation,therefore,was to obtain

data such as the load at whichinitialyieldingwo,~ldoccur,the maximum

strength,the energyabsorptionand ductility,end the tit straindis-

tributionin the regionof the openingfor plateswith typicaltypesand

amountsof weldedreinforcement.

The scopeof the initialpart of the“investigationincludedfive

seriesof epecimenstestedat room temperature!plainplateewithout

openings,plateswith unreinforcedopenings,plateswith openingsre-

inforcedby face bars,plateswith openingsreinforcedby singledoubler

plates,and plateswith openingereinforcedby insertplates.

-l+-

.,Each ‘iif’the &briesof”specimens~<th openingsincludedthreeshapesof opening:

&Feilar,’squarew$.throunded’corners,”an~ squarewith”sharp~orners. The body

“or tiiriplateofleach specimenm’s“cutfrom l/l+-irichplate. The programof.

t&~s wfichwill“followthis&itial proowaintichdes spectiensof greater

th~cknessas hell as spec~ens of the“d~ferentthickrlessestestedat low

fi ... !,. .

atmospherictemperatures.

,. ‘,.’. .

Iv. TLsTSAND TESTMETHOl15-,:...,,,..:,.,:,... .. .,.,.

1. SpectiensSteeland Welding,Electrode..

.411the specimensfor t~s seriesof testsWere,$,,xnpi.etelyfabricated

fromthe sameheat of steel.,,Thissteel,hereafterdes~+t+d as SteelU, was

a plain-carbonsemi-kill.edgrademeetingfi$JMSpec.1(o.A 7.-49Tand v@?,used in

the as-rolledcondition. The chenicalanalysisof this steelwas as follows:.

,..,“c’ ‘“”’Ml ‘ P s ““Si‘“

.,0.23 0.50 ‘“0.053““ 0.051““‘“ 0.07

“Thetensilepropertiesof this’steelas determinedby testsof two,. :..,

ASTM standardfl~t tensile‘specinens““cutfi’omeachplateare given~“ Table1.

,,.,,. :,. .The microstructureof “samplescut from one plateof eachthicknessare shown

.in‘1’i”g. 1.

‘The’coated‘weldingelectrodewas 1/8 in. and 5/32in. h’ diameter,,

and’“metAVE Speti”.‘E-601O.

2. Detailsof TestSpecimens,,,.

The”spec”inens””were designedand weldedin accokance”w~th Navy4.

Specificationkavships451. ‘“Theweldswebe designedto havean efficiency,. i,,. ‘,.

of 100-percefitaccordingto””th6SeSpecifications.Sketchesshowingthe five,.,,, ,. .

,.,...,,,.,.;.

.,,,..;...;r,,... ,.’,.,

“+

types~f specimensand the detailsof the weld~g appearti Figs.2, 3, k,”and

5. Table2 I.isttithe testprogreni;

All plateshsd a test sectionwith the samedimensi~s,36 in. wide

by 1/4 in. thick,as shownin Fig. 2. Figs.2 to 5, inclusive,ShOWthe shape

of the openingwhichwas locatedin the centerof the test sectionand the

detailsof the weldedreinforcement.‘lheouteredgesof the sp%c~~s and

the circumferenceof thetipeningwere flame-cutto shapeand groundto remove

the roughnessleft by “the’flame-cutting.The-.doublerplatesad the insert

plateswere also,flarie-cutto shape. However,the face bars‘tiers”sewedto

width.froa@-in. platesratherthanilame-tilt”;ti orderthat the”&ternal

stressesin the facebarsmight be simil.ar’tmthose’in hot-reliedbars,which

woul.~ordinarilybe usedfor thiskind 6$:strtictti~detafi. The face bars

were sold-benttoshape and splicedwith‘siiigleV-buttwelds”on the vertical

centerline,of,.theepectien. Thosefor the cficularopening‘were”made in one

piece,and,thosefor the.two typesof squareo“pefigsin two halves. Tabls3

liststhe plateefrcm whichthe detailsfor each specimenwire cut.

All filletand edge weldswere laid in one~pass ofthe welding

eJ.ectrode.,The doubleV-butt.weldsrequiredone pass on each sideof the

plate,.,,plate bevelsfor edge or buttweldswere‘preparedby Wd grinding.

The surface of the edgebead on the.circumferenceof’the openingin the speci-,.,

mens with doublerplates:was@ound to rdmove‘thesurfaceroughness.

●

,:Becauseheat-straightenrhi~mightintroduceundesirablestressesand

advert+.y@feet the ductilityof”the”eteel,very carefulprecaution were.

takento mir@zizethe.shri.mageresoltingfrom the hsnd-weldQgproc;ssto

-&

the degreethat straighteningwould,be unnecessary.A,$>g Was b~t in which...

the specimento be weldedcouldbe clampedbatweentwo heavyplatesand,r?●

tated.throughan angle.of 180 degreesto permitthe ~ying of ~ we?.dsin the

flatdownbandposition. The weldingprocedurewas arr~ed so that,$he welds

wereplacedin shortstepswhichwere

of the reinforcementand from face to

pass.start+dor sndedin the vicinity

systemsticaIJ.ylaidfmm side.to side

face of ,thespecim~. Moreover,no

of the regionwhichthe fracturewould

latertraverse. Time was allowedbetweentheseshortpassesad beforeremoval

of the platefrom the jig afterthe completionof all wel.dLngto permitthe

spectiento cool, The maximumwsrpagewhichresultedfrom this,weld-g pro-

cedurewasnot greater than1/2 in. in the.seven-fcd lengthof the,r.pecben.

The metnodof fabricqticnfollow+,very closelythe usual,procedure

in a fabdicatingshop..expept ,+hatmore carewas tekenin Cuttingthe atr.UCt~?l,

detailsto exactdimen~lo,nsand in holdingthe

is requiredb~ commerci+ specifications.The

at leastsevendays afterwelding.

3. Methodof TestingPlateSpecimens.

The platespecimenswere testedin a

weldsto the specifieds+z.pthan

apeckens were not teateduntil

,.

2,400,COO-1b.capacity~iversal

hydra,pl.ic”testing,nchiqe. The specimepsweremountedin the teetingmachine

by butt-weldconnectionsto the @Q.ng heads. The two pullinghesdawere free

to swivelon the pins of two clevisesattachedto the headsof the testing

machineby sphericaljoints. The verticalcenterkne of the specimenwas

alignedto withinl/l&in. of the l+e jo@ng the centersof,the two clevis

p~. s. A typicalplste specimenmounted~ ,thetestin~machineand readyfor ,

testingmay be seenin Fig. 6.

-7-

“Tbeload was:’8pplied“’slo;l~to the specimen,and”reddirigibf the.. ,.

gagestakenat’frequent“intervals.The Samescheduleof lCadswas “kpplied

to all specimensin orderthatcomparisonsof the elo~atlons =d unit,,;

strainsmightbe made at the same loads...’ .,;

.. .4. Gagingand Measurements.

,.’’.,,The priicipe~meas~em6htsmadewere the elongationOn a 36-in.

,.,gage lengthstraddlingths regioni~tid the”openingand tie“mit”strain

distribution”in one qtidrantof “thespecimenlyingb&,&&en~hd”%r~ical

end the hoiizontalcerterl.lnes.The““36-G.gagelengthbidgbd most of

the portionof the sp~cimenin which‘theUnit etressesWere”ndn-uniform.

“The36-in.“gages“werelocatedon both’’faceeof the pla~eon’four squal,...

spaciii@acrossthe iidthof’the apechen a-i“shownin Fi~. 2.

SR-4 iiectric’s~raingageswere used to““deterblnethe’unit

straindistributionin the one quadrant‘ofthe sp&imen ~ ‘“ti<eel’astic

rangeand the earlyplasticrange. Theseelectricstraingageswere

mountedon both facesof the pla$esto removethee~fect o!;:be:d@g. ..

from the readings.The,number,of SR-4 gagereadingaon the singleSpeCi-

mens variedfrom 33..to 56 accordingto the shape.wd the lc@d Of the re-

inforc.ezent...-The locationof the electric,stwin ,g@ge,s.OQ the different

typesof specimens,is phowm.inFigs.7 to 10, im’?luSiVe.: ! “

A ,mber of ayxiliary,observ@ionswere made. The firstspeci-

mens testedwere coated,with$tresgcoatfor the purposeof indicatingthe

principalstresstrajectoriesend the @nt?, of initial.~elding. HOwevar,

sincethe Stresscoatwas.sprayed.and:.t.estedunderconditicmeof varying

temperatureand humidity,the behaviorof the brittlelacquerwas somewhat

-8-

erratic. Accordhg&, ordigarywhitewashwas used on the hter tiste.,.

The locationend the directionof the p@ncipel shearstsesseaat ~-

tialyieldingand duringthe euhseq~nt p~stic flowwere clearlyshown

by the wlitewash.

The distortionof the openingat thy.higherloads~d the pr~

greseionof the freoturewere measuredwith a scalegraduatedin one-

hundiadth@ches as well as the lateralbucklingof?the regionsunder

compressionstressadjacentto the opening. Thesevariousa~lierg ob-

servstionawere usefulin evaluatingqualitativelythe stateof stress

in the epecimenwithinthe plasticstressrange.

Since tinetestewere ssde at room.‘temperature,,,.the temperature

of the s,pecimenwae measuredwith stificlenta@wracy by a merctuyther-

mcyoaterwhich.yaain intimate.the-l contactwith the platesurfaceand

insulatedfrom t~ surroundingatmosphere. ,.

“’V, RESULTSOF TESTS

1. Introductionand Definitionof Terms.

The resoltsof the tweY@-threktestsof plainplates,plates

with unreinforcedopenings,”and ~lat’eswith reinforcedopeningswill be

presentedin the followingaec$ion. NO two”of the twenty-oneplatespeci-

menswith ep&lngs were alike,and, accordingly,comparisonsof the re-

svltsof thesetestsmustbe tide on a ratherbroador generalbasis.

Duplicatetests‘of&y of theseapeclmenswouldumdoubt.edlyhave given

soukwhetdifferentresi.il.ts.It was found”quiteoftenthat the platea

.

*

1

with the sate ahapeof openingbehavedmore nearlyalikethanthe p’btes

-9-

with the same typeof .reinforcernent.Trandsare ahomnwhereverthe data

indicateddefiniterelaticmsBetweenthe veriable.s.All the teetsde-

scr$hd in thds reportresultedin .cempletelydutitilefrecturae.

Some of the termsto he usedin the followingsectionshouldbe

clearlydefined..The elongationsmeasuredove~K %in. gege“lengthat

five pointsacrossthe width ofthe plateas shownin Fig..2were

averaged.and the resultingveluecalledthe averageelongationon the 36-

~n.gage length. The term,loadat generalyielding,of the specimens

was appliedto the pointwherea definiteeltmwappearedin the plot”of

the totalload on the pla@,againstth~,,e~rageelongat-ionon‘the3Gin.,.,

gage length. :- ..’

The ultimateload,the maximumload sustainedby the specimen,

was di@ded ,~ the origin@ net cross-sectionarea of the specimento

give the valueof the maxirnupaveragenet stress”or ultimatestrengthof

the plates. The totalload on the specimenwas plotteda~inet theaver-

age elongationon.the 3.6-fP.gage lengthfur each sped.men. The area

underthiscm.ve,.orany portionof~~it, representedtheenergyamorption

of the specimenup to the pointunder

energyabsorption.have be~ repQrtedj

the energy-to.failure,”.’“.: .?~:

~,.The threeshapeeof.opening

consideration.Two valueeof the

thetiergg to ultiioateloadend

will,be referredto as circular,‘”

squarewith roundedcorners,and squsre. The dimensionsand the cornwr,

radii of.these openingsare’shcwnin Figs.2 to 5, inclusive, The plates

withoutopenfngswill beailed.plainplates.

-1o-

in computingthe percentageof reinforcement,the unreinforced

plateswith openingeone-fourthof the fullwidthof the specimen

were consideredas bevlngzeropercentageof reinforcement.The per-.,

centsgeof reinforcementwas comp@ed as the ratioin percentbetween

the additionalnet cross-sectlenarea addedto the unreinforcedspecimen,:...

and the crosg-sectioparea”of the materielremo~d frOm the bdy Plete

by the opening. A reinforcedplatewith a net cross-s,?ctionareaeq~l

to the area of the plainplatewouldhavea percentageof reinfacement.

of 100 percent.

2. DistributionecrossPlatsQf Elonmtion on 36-in. Gage Lenrzth.

The elongationwas measuredin the directionof the applied

tensLonat five pointsacrossthe width of

Fig. 2. The distributionacrossthe plate

11 to36-in.gage lengthiS shO~ in Figs:.,

the specimensas describedin

widthof the elongationon the

33, inclusive,for each of the

tme”nty-threeplatespecimens.Measurementswere takenafterpassingthe

ultimateload,but were not plottedin thesefiguresbecausetheywere

more dependenton the progressingfracturet+an on the elongationof the

material.

The elongationof the specimensremainedfairlysymmetrical

aboutthe verticalcenterlineof tbe plateuntilfract~e beganat, or

just beforethe ultimateload. ,~ithfew exceptionsthe elongationwas

greaterin the centerof the specimenthan at,its edges,both for plain

platesend plateswith openinge. The distributionof the elongation’across

the plateswas more or lessthe

changedby the differentshapes

enforcement.

same in shapefor all the platesand was not

of openingsor the differenttypesof re-

.

●

,

-1.1-

The elongatioxisat ‘thefive pointsacrose“thewidthof the plate

were averagedto oblxiinthe averagaei&gation on the 36-in.gage length.

A comparisonof the averagee~~gatiop’~’titiwte’ load‘andto failureis

shownir:~ig.%. The valuesof the average“elongationat titlmateload

rqed frOm 36 tO 85 percentof the valuesof th~ averageelongationat

fbllure.Apongthe plateswith squareopenings,“,thisratiorangedfrom,,,,, .

36 percentfor Spec.No. 19 to .59pero,@,for S$CS. No. 3 end 20; among

the plateswith’equsreopeningewith roundedco~+r:,..<??E..5,?PercentfOr,. . .. ........ ,.

Spec..No. 22 to 78 parcentfor Specs.No. L and 21; and’amongtk”plates

withcircularopenings;frem 73 percentf~r Spec.NO. 6 to 85 prcent for

Specs.No. z ~d 1.8.For the three shapes“ofopenimgs,the”rattbbe-

tweenthe averageelongationto.,ultiuateload and the atira~:elongation

to failureincreasedin the followingorder: squareopening,square

openingni+hroundedcor.ne~)~d circularopening.~..: ‘.

The shapeof the,openingatioeffected.the total‘amount:of~blon-

ga$ionoccurringbeforefailwe....The.magnitudes,of the avarag~.elong&-

tion.to failurevs~ied.withinapproxlswk.elythe samerangeforthe ‘plates

with circularandthose.with~uare openingswith roundedcornars,but

were greaterfor all the speci~ns with thesetwo shapesof,.operiingthan

for any of’the plates.. .... ..

failureon the 36-in.

t.o,1.82in. for Spec.

with squareopenings..,:7he.+aye$c+ge,,elOriga.$iQnto. .... ..

gagelengthrangedfrom4.01 in. for Spec,..NO. 10

No. 3 as.co,mparedtovalues of 9.C3 and 12.35in.

for the two plainplates. The largeetelongationto faihre of all of

the plateswith openings.was onlyLO percentof the le,ss,erof the two

valuesof the elongationto failure,for tiw plainplates.

-IiThe followingtabul.atlonItits the speoimsneIn decreaehg order

of magnitudeof the averageelongationh failure: .,,.,

,,

Orderof s~c. Shape of Opening Type ofMetitude No. Reid rce0 nlant.:.

1 10 Sq~e, RoundedCorners Face ~r ..:..:.,.2 21 Square,RoundedCorners InsertPlate

17 circular:

Insert.Pb.te5 Circular Face Rar

Circular ~ DoublerPlate2 ;: Square~ RoundedC6rnere Doulii&”Plate7 18 Circular lne@ .~+tte8 2 Cf.rculer None

,, .

Ae thietabulationindicates,the avaregeelongationto:dfeilorewas not

consistentlylargefor any particulartype of reinforcement.However,the

lergeatelongationsustainedby a platewi~out re~o~ckbnt arod the

openingwas only eighth& orderof”magnitudeor 78 percentof the value,.

for Spec.No, 10.

The averegeelongationin

listedin Table1 was 29.1 percent.. ,,

the tinsilecoupon“tazto“’~e”‘<cd to..

.,8 in. of the nine l/4-in.platis

If the averageunit elongationfrom

predictthe’total’elongatlouin the,.. .

36-in.gagelengthof the plainplatee,the valuewouldb 10.5 in. This,,, ,

‘, :.’valuecompareswith the‘act~laverageelongationof 9.83 and 12.35for

.... ....Specs.w. 1 and 23.

,.:,

3. Comparison‘of“~ad on S~;&n andA

,,veri~e Elongationon %-in. Gaee

., ,:,“ Leneth.

The totalte~ion load on the specimenwas plottedagi.&tthe,..(.. ... . .,, ... ‘..1 .-,

averageelongationon de “~-in.gage“lengthto”obtaint% res~ta “ehown,,, ,,

in Figs. 3S to 39, inclusive.The specimens=e “@oupedin“eachp~t ac-,,,, .;. . ,.. ”

cordingto the t~e of re+tiorcemant.

-1.3-

‘fheredts ShOWS h Fig. 35 fOF the bO p~~? Pti~ ‘~re ~tie,. !.’ .,,.... ........ ... .,.. ...........>.. .-

eicepttht ~~c”;”’No.”’2>s~hhd a greeterawra~ elonga,t,ionto fai.lure..... ... ..;.,,,

thenSpeC9No. 1. lieoiingnf tie”’crossseotiOn,of tb pl.+.nply,:e.?+-,. .,, .. .::gan”’at the u.lt~t;”load~ continueduntilfractures+ted at,,a load,,..., ...

.,. ,..not fer belowthe ultimateload.

,.,..”.. .-..’.:, .The plateswith unralnforcedopaningeaa shown~ Fig. 36

.. .

followedalmosta commoncurveae the load increased~~11,E p~t ,ff~~

tha ~timste load of each sp8ciumnwas reached. Spec.No. 3 wi~,,the,“.

equereopeningsustaineda ssmlleraverageelongationthan+sc. Fo. 4.....

with the equereopeningwith rcundedcorners. Spao.I!o.,2with the OiT-,,

c“uleropeningunderwentthe I.srgeatavarsgeelongationof the thee Plqtes.

The behatiorof the plateswith reinforcedopenings,ehownIn

Figs. 37, 38 end 39, waa similarto that of tha unreinforcedplatesexcept,.

that higherloadswere reachedbecaueaof the increaaedcrose-sectl,on,,.

area addadby the reinforcement.The edlest averageelongationconsis-

tentlyoccurredin the plateswith squareopenings,while the average,.

elongationof the plateswith aquereopeningswith roupdadcornersand of

thosewith ciroularopeningsvariedconsiderably,but were of the same

orderof magnitude.

Since all the load-averageelongationcurvespoaaeaaeda common

shapeup to a pointnear theirultimate’load,it seemedlikelythe++some

relationexistedbetweenthe magnitudesof the ultimateloadand the aver-.,

age elongationto ultimateiced on the 36-in.gage length. Pig. .?@8hoWS

this co&srison. The ultismteload increasedin directproportionto the

logarithmof the averageelongationto ultimateload on the 36-in.gage

length.

-u-

4. GeneralYlahu in the PlainPlatesand the Plataauitb OIXniXlg+@........

YieldingbaganIn very SmellregionsOf t~ s~~ns et 1~,.

loadsas wifi“k shownIn a subseqwnt sectionof thisreport. However,

otiy wry slightchangesin the slopeof the load-averageelo%ation

curvesin Figs. 36 to 39 tookplaceuntilyield+ng&d spreadto a larger‘7 ‘-,

portionof the area aroundthe opening. Thispointof the load~~rage

elongationcurveat whicha sharpchangeof S1OPBoccurredwas teed,..

the load

yielding

at generalyieldlng.

The valuesof the loadand the averagenet atres?at general.

are plottedin Fig. 41 and givenin Table4. While.the V:lyes

of the totalload on the specimenvariedconsiderq~y,the .yaluesof tie

averagenet stressat yieldingwere morenearly@form end varied.fl’om.,

36,360psi for spec.No. 21 to 45,500psi for,Spec,.XO. 6. The net cross-

sectionarea of the formarspecimenwas 8.17 sq. in. and.of the latter.,

7.25 sq. in. The averagenet stressat generalyieldingin the plain

plateswss &,220 end 43,330psi for Specs.no. 1 d 23. AD ,%=mine?iOn

of the valuesin Fig. Q and Table4 indicatedthatthers..Wasno Siwle

relationbetweenthe averagenet streesat generalyieldiqgand the ebape

of the openingor the typeend amountof reinforcement.

In Table1, the averageupperyieldpointsof the platesOf

variousthickneesweref+.f+,500 psi for the l/4-in.plate,36,500psi for

the l/2-in.plateend ?2,800 psi for the l-i@.plate. The averagenet

9t~8S at generalyieldingrangedfrom 36,360$.o45,500psi for the ptitei3

wttii”openingsand was 42,220and 43,330psi for the two l/4-in.thick

plainplates.

-15-

5. UltimsteStre!x?thof Plainp-t -platis with.Ooe$xin@s.,.,,’”,

},., “‘The‘ultlm%tas~ength of the pl@n pla~s..,@idt?+.phtSS,,:,

Openingsla shownin Fig. u and tabulatedin ~~~e 6..,Thq VElhlSS

ultimateload for the plataswith openingsyu’ied.frorn357,500lb.

Spec.No. 3 to 5s5,0Q0lb.”for Spec.No. .1.1,@, the valuesof the

timatistrengthfrom~7,690psi for Spec.No. 19 to fi7,SO0psi for

with

of the

for

ul-

Spec.

No.’:‘5. The ultliates~~ngth of the two plainpla@s,,was ,65,390and 6.?+,780

for Specs.No. 1 and 23. The titits strengthof tm plateswith.,:.

openingswas eitherapproxJmstalyequalto or,less than the ultimate ;,~.,..~

strengthof the“plainplatee. The a~~~ tittite strength.of the

platesof differentthicknessas determinedby ,thatsnsilecoupontests,,..,, :., ,

are reported”‘“asfollowsin Table1$ 65,700pai,f?sthe 1/4-in,plates “‘“

and 61,100psi for boththe l/2-in.and the.l-in.plates..,T@ ultimate

strengthof the 36-in.wide plainplateswas approximat@y,tb. same as fori,,

the smell.tetis~lecoupons. The ultimatestrengthsof.,,~,plateswith

openingsrtiged““from”approximately75 to 100 per~ent~of the ultimate.,.r

strengthsof the ‘plainplatesand the tensilecoupws.

The relationbetweenthe ul.timetel~d,sustainedby the platss,.,~:”1

with openingsand the”percentageof reinforcementis ?ho~ in Fig, ~~s

and the relationbetweenthe ultimatestrengthand the pe~eptaga of re-

inforceumntin Fig.“‘L. In thesetwo figures,the plottedpointsfsll “

into bandsaccordingto ths shapeof openingused in the specimen. Tb ,.,.:,

ultimataloadand the ultimatestrengthincreased.in the orderof the sbiip6‘“’

of the Operiing”a8 follows: equare,squarewith,roundedcorners,and cir-

cular. L mbeh smellervariationwithinthe bandsfor each shapeof opening

was notedas the effectof the type and the amountof reinforcem@t.

-16-

,....’,>. ,:,,., ,., ,., . .

The ultimateload’inc&aaed as shownin Fig:4>’$th ~ increase

of * percentageof reinforcement..However,the”ultimatestrengthof

the platesin Fig. &$“dec;asedas the prcentage’of reinforcementk-~... ..,..;,

creased. While a definltac- cannotbe accuratelyd~wn throughthe

plottedpoints,the ultimateload increasedand the titimstastrength

decreasedat aboutthe EIamerate for all threeshapesof openingsas the

percentageof”reinforcementwas increaeed.

The plote in Fige.~3 and ~ wouldbe identicalif the oltisate

load and the ultimate’stre~th ~d beenplottedagainstthe net cross-

sectionarea of the‘plates.“’‘&refore, it may be seid thatthe U3.tis-ate

load Increasedend the ultimateetrengthdecreasedas the net croes-,.

eection“areaof the plateswith openingswas increased.,.. ,-, , ? ‘,

Since the ultimateloadend’the ultimatestrengthdecreasedin!.

Figs.43 & ~ ag tk cornerradiusof”the”openingdecreaeed,%t was

qperentthat the notch-affset of the openingwas verysignificant.The

relationbetweenthe ultimatestrengthof the plates@th openingsand

the notchacuityof the openingis shownin Fig. 4s. The notchacuityof

the openinghas been expressedin the fo~ of the ,~tio,,R~, t&e ratio.,

of the half-widthof the openingto the notchrsdiuewhichis in this caae

the’corierradiusof the opening. The actualmeasuredcornerradiusof

each specimenhas beenused to computathisratio. An increasein the.

ratioR~ indicatesan increaeein the eharpne~teof the notchae.~.pr~

aentad by the opening. In Fig. 45 the ultimateetrangthof the platee,....

with openingsdecreesedin a linearmannerwith the logarithmof the ratio,.,

.

r

-“”17-“”

.: ... ,.,..,..,.!The”etii~’’Ago~ti&”’~ “~t~~ load‘kd”to‘“fati~e”of‘the“ “’

,,.,.plalnplat.aa~~ek~”{he’‘&ate?ki.h opirii~a1S:~joiiit’in’’’$ig~“’46’’&2:~ii.

,,, ,.:,..,,,,latacliriTatiL&’~.:”Ph&’-~nergya~o~ttin to‘ktfkte-’ioadwas ~;O18~OO0”

,...... ;:,,,,:.,. .,{.,.,..: ~:,,,,,“and&;062#O06““ti-lbi’for the two”plainplatee~“:Spe&.~o. 1 &d 23,”and

amongth6“’ti&@-one”plakkswith““openings&led” ‘~~m’‘~9jOOO:‘~-lb~”for,,, ... .

SpaC.No. 19 to 1,358;CO0in-lg~<’forSpec.”lto~11.“’:’Th~“erie+wabsorption

to ultimateloadfor the pleteawith open$ngerangadfrom 6 to & percent

of the

in-lb.

,,, ,.:. . ,,, ,.. ... ,$. . .. .

valuesfor the plkinplates,“

The energy“absorptiontO ~iii~e”WCS 5;Z76;~b0end‘~~779yOOO””‘”,.. ,:.:, ..~,..

for the two plainplat.ke;Spc’cB;NO.’‘1”L8: 23, and ~ong the p~tas,., . ,. , ,’ .,.,:.:: :’

~$tti ,Opening= ~ied :&i.,.,538i coo .in:l’bi For g-pee.~o:”’,3 to ~;”5@;ooo

in-lb.for’Specii?o.11..:[:

The’”hiiirgyabso~~idn”*O failtiefor the piatea..$,..;-,.:,,,;,..,.

wi~h.openingsrazigedfrom 9‘to’’26pe$c~nt;’“of’<he”Aues ““for the plain ‘“’”J:,..,:,..’...,, ...?,,:, .. .. .

pl.atee. >

.,:.’,,1The madmum valtiea-of the enek~’to”~~imste loadkh the ener~

,.to failurefor the plateswith equar&.@&ngs wereleBa tbiiith<iihdmk

valuefor the plate’swith‘the:ckhe$’&’o’shapesof opening.

Fig. L7 ~hoe~‘theco~rr$oti‘Ofthe energyabaorpti’on’”’to“fki~;e

:!“ .~and’the percentageti~‘r’e”tiin.cetienta“ewe’llES the net “cross~ect”ionarea

of the plate.~”‘Theplotted“&i&t.sIn this“fig”ti’“f~1” ‘&to’“twobands,“a.

groupof lowerv=aluesof energymbso~tioti’for the plateawith equare

openingsand “a&dbly scatteredgroup”of higherval.u&’‘forthe plates,.

with the otherttioshapesof ‘openhg,the squareo~ning tith ro~ded

.,.,.4

,,, -

... ,!.,,

cornersemi the

inforcem&t for

-18-

circularopening. An increeee in the percentageof ra-

the plateswith squareopehingstmught aboutno a@ifi-

cant changein the energyabsorptionto failure. The trendfor the

plateewith the otherehapaaof openingsie leeedlecernikla,but no,:

elseablei+creaaaor decreasein the energyabsorption~ failurere-

suitedIn the plateawith squareopanl.ngewith rounded’c~ere or the

plataewith circuhr openingswhen the percentageof reinforcementwee

increased.

The effectof the notohacuityof the differentehe+peeof

openingsupon th ultirateetrengthof the plateswith openings”was

foundto te ratherolearlydefined. A similarrelationwas foundfor

the energyabeor@ion of the sameplates,and Fig. 48 shows”tbierelatiofi.

In general,the logarithmof the ener~

plateswith openingsdecreaaedlinearly,,

R@N. The trend,however,was eomewhat

ener~ to failurethanfor the ultimate

7. EffectivenessQf the b~orcement.

absorptionto failureof the

withthe logarithmof the ratio,

lees clearlydefinedfor the

atrahgth.

Gne purposeof the reinforcementia that of restoringas mush

as,possiblethe propertiesof the plainplat%. The ratioof the value

of comeparticularpropertyof the pleke’with an epeningb“ the aisdlar

valueof the plainplateumy be calledthe efficiencywith r;a$ct to

the propertyunderconsideration.Table 5 tabulatesthe efficiencies,. . ,

of the variousplateswith openingswith reepectto generalyielding,

ultimatestrength,and ener~ absorption.The shapeof the openingaa

well aa the type and amountof reinforcementis indicatedfur aech speci.

man. The ~rage of the valuaefor the two plainplateswas used as

the taslafor each comparison.

:19-

,,,.. The v@.#s OF + effictenciee.in Table 5 indicete~ ad~~te

the rqlnforcementwas @ r@or@ the-propertiesof the plalnplate.

Inasmuchas the averagenet streeeat generalyieldingdid not vary

ap}resiab~ for+ha platee:with openings,the efficiencywith respect,,. .

t~.,,.theload@ avera,genet etreesat generalyieldingdid not vary

througha verywide range, However,the ultlnnteetrangthand the

energyabsorptionof the plateswith openingswere &eatly effectedby. .

the shapeof the openingand the typeend amountof reinforcement.

Fig. 49 is a type of plot in @ich the efficieneywith reepect

to two differentvarietiescan be compared. In this comparisonof the

efficiencieswith respectto the ultimateload end the energyabsorp-

tion to.,failure,the pointsplotted In the upperright-handcornerrepresent

the specimanewhich gaw the highestefficiencies.The specimenswhich

gave the bestperformancewere thosewith circularopenings-orwith

squareopeningswith m?updedcorners,whilethe specimenewith the worst.. .

performenc.eincludedall thosewith equareopenings. Fig, 49 also in-

dica$esthat the spec~ne which sustainedthe greateetult@te, load .

consistentlyabeorbedthe largestamountof energyto failme..,

A piot similarto.Fig. 49 is shownin Fig. 50, in whichthe

effici?ncleswith respectto the ultimataetrengthaiulthe energyabsorp-

tion to.fallureare.pl.o~ted.The specimenswhich sustainedthe highest

ulti~te strengthabeorbedthe largeyba~unt of energyto failure.

.Witbthe nid of Flge.49 and ~O)..the specimenewhichgave the

best performancecan be selected. A line has beendrawnwhichdelineate

thosespecimenswhose efficiencieswere greaterthan 80 percentwith

reepactto ultimateload,88 percentwith reepectb ultimatestrangth,

and 15 percentwith respectto energyabSOI@fOn b ftime. The .

-20-

,,.performanceof thesesuperiorplateswith reinfo~ed 0p6nings~e described

in Table6. The fol.1.owingobservationcan be zade concerningtheee

specimens:

1. The nine plateawhich gavethe bestperformancehad either

circularopeningsor squareopeningswith roundedcorners,

and all had weldedreinforcementaroundthe opening.

2. Spec.No. 11 whichgave the tmstperformanceend Spece.No. 5

and 18 the neti bestall had circularopenings.

3. The nine best specimensincludedtwo with face bar rein-

forcement,threewith insert‘platereinforcement,and four

with doublerplatereinforcement.

One interestingobservationaboutthe plateswith equare

openings,eitherreinforcedor unreinforcsd,is that theirperformance

was worsein everycase than thatof the ~einforced plateswitn‘the

circularcpeningand the squareopeningwith roundedcorners,Specs.No. 2

and .4,respectively.

8. UnitStrainConcentrationin the Plateain the Regionaroundth.~Ooaninr.—

ManySR-4 electricstraingageswere locatedin one quadi-ant

of the plateswith openings,the quadrantlfingbetweenthe verticaland

the horizontalcenterlinesof the specimen. Elasticstrainconcenta’ation,,,,.,,::

curvesbasedon the data of theseobaervstionsare shorm in Figs. 52 . .. .

to 7z, ~clusive, The @rtical directionin thesediagramscoincides ,.;,

with the directionof‘thetensionload. The sketchin Fig. 51”explains

the mannerin whichthe unit fitrainconcentrationis presentedfor the

-21-

,-

1.

20

3.

4.

opening

For

the

For

the pletaswfth circular,:-gs, the horizontalcenterline,

unit strainking takenin .t@ verticaldirection. ~

the plateswith equareopen@gs with rmmded.cOrnerS,a

horizontal”l~e ~ssimg throughthe pointof,.t.qgencybetween,. ...,

the verticaledge of the openiggand the corper.arc, the:unit

straioabeingtakenin the ~rtical direction. ~~:

For the plateswith squareopenings,a horizontalline through

the cornerof the opening,,the.wlt strain?being takenti the

verticaldj.rection.,.

T“hecircumferenceof the,o,peningfor all specimens,the unit

strainsbeingtakenin a directionte?gentir+to..the edgeOf

the opening.

The strainmeasurementsshownnear the cornerof the square

in‘plateswith equsreopenings,were actually,locatedI/l+-in.from

the corner’“asshownin Figs.7 to 10. Therefore,

gageewouldnot determdnethe maximumunit strain

near to the corner..,

the,read$ngsof these

which WOtid OCCUr Very

The unit strainconcentrationfactorswere computedfronithe

SR-4 atreingage readingsin the followingqsgner. The totalload on the

specimenwas plottedagainstthe SR-4 strainreadinga}.,eachof the gsge

pofnts. The curve“throughtheseplottedpo~ts in the.~lastic,rangewas “‘

aPProAmtely a straightline. The slopesof the variouecwves were com-

paredwith the slopeof the cameplot i+ th,eregionof the plate‘remote “

from the opening. Thus,the ratios,‘deter+ed by this comparisonwere in

realitythe unit strainconcentrationas comparedto the unit strainin

the regionof the plateundergoinga uniformstressdistributlonacross

the platewidth.

-22-

This approachwas necessary,becaueeof”the natureof the S%4

readings. First,thesereadingswhen plottedalongwith the load on the

specimengavea curvefromwhichmany of the plottedp@nts at lowerloads

detiatedcone,iderably. This effectcouldprobablybe attributed,to the

residualstreesespresentin the specimenbecauseof flsmeouttlngand

welding. The directtensionincreasing,theseeffectsbcame ProPOrtion-

a~ less thenat lowerloade. Secend,someof the SR-4 gagesindicated

an earlydeparturefrom linearity.asthe resultof yieldingat loedsvav-

ing fromapproximately30,000to 6c,000lb. for all the specimens.

Each shapeof openingpossessedthe same charactarist,icform of

strainconcentrationcurvefnr unit strainsin the verticaldirectionwhose

shapewas onlysomewhataffectedby the type of reinforcement..Theehepe

of the strainconcentrationcurvefor circumferentialunit strainswas

somewhatsimilarforths plateswith squareopeningswith ro~ded corners

and for thosewith square,openinge,but was differentfor t~ plateswith

circularopenings.

In Figs. 52, 59, and 66, the unitstrainconcentrationsare

ehewn for plateswith unreinforcedopenings. The unit strainalongthe

circumferenceof the openingin Spec.No. 2 with a circularopening(see,

Fig. 5.2)changedgraduallyfromtensionat the horizontalcenterlineto

compressionat the verticalcenterline.For Spec.No. 4 with a square

~peningwith roundedcornersand Spec.No. 3 yith a squareopening(see ,

Fige. 59 and 66), the tmit strainincreasedehsrpiyfrom tensionat the

horizontalcenterlineto a much largertensionvalueat the cornerand th?n

f

.

-23-

droppedabruptlyto compressionas the oornerwas passed. The shaps

of the unit strainconcentrationalongthe circumferenceof the opatig

in the plateswith end withoutreinforcementwere similarfor eachshape

of opening. .’.

The shapeof the unit strainconcentrationcurvesonthe hori-

zontaleectionsof the specimenswill now be &arnined. ThA shapesof the

unit strainconcentrationcurvesalongthe horizontalsectionthroughthe

openingwere similar,in general>exceptfor smalldifferen~e character-

isticof the typeof reinforcement.Ii the “caseof the plateswith a

singledoublerplateand some of the specimenswith insertplates,a

second“point“of~high unit“strainctikentrationappearedat the,outeredge

of the reinforcement.

The greatestdifferencethen in the shapeof the ~it strain

distributioncurveson the variousedct.lctisof the”ep&?im~s occvlred

alongthe circumferenceof the openingwherethe straingradientwas much

steeperin the plates‘wfthscpxir.s‘opetin@with roundedc$rnersand the

plateswith squareopeningsthen in’the plateswith circular:openings.

In a veryshortdisttincs“alongthe circumferenceof the Opehingin the

vicinityoflthe cornerof the openiog,the unit strainsfor the two typee”

of .iqusreopeningdecreaeed

the maximumtensionvalue.

of the pointof the msilmum

cf the circolaropening.

vetirapidlyon bcth sidesof the pcintof

The slopeof the straingradienton each””side

tensionvalue,wasvery gradualin the case““

..

The additionof srxwelded reinforcementchangedthe character-

isticsof the unit strainconcentrationcurvesin twc importantrespects,

-21+ -

as comparedto the curvssfor the unreinforcedplates:

1.

2.

3.

4.

The effectof

opening.

The

‘l’hemagnitudesof the unit te.neionstrainsin the vertical

directionalongthe horizontalsectionthroughthe opening

were Increasednear the edge of th openingand reduced

near the edge of the plate.

A secondmaximum,in sozm casesgreaterthen the concentra-,,,

tion velueat the circumference,appearedin the regfonof

the welcibetweenthe doublerplateor the insertplate

reinforcementand the bodyplate.

The unit atrsinconcentrationat the edge of the platewaa

reduced.

The magnitudesof the unit compressionstrainsalongthe

verticalcenterlinein the regionof the openingwere

reduced.

the reinforcementwas similarfor all threeshapesof

unit streinconcentrationin tineregionof the openinghee

been discussedso far in a purelyqualitativemanner. The closerexamina-,.

tion of the behaviorand the magnitudesof the unit strainconcentrations,..

In the variousplatessuggest,that the methodof fabdicationof the

specimensis responsiblefor some of the discrepancies.The introduction

of shrinkagestressesalongthe edgesof the apecicmnsby the flame-

cubbingprocesswas followedby the additionof ‘otherresidualstresses

by theweldingprocess. Afterwelding,the specimenswere observedto.,.

-,

-25-

heve slightlydishedshapein the vicinityof the epening. This dle@d

shapewae reducedto a flatplaneduringthe coureeof the.teat,+Y

afterextane~~”fldding bed progressedacrosethe width of the platea%

a load far in excessof the had8 at which the SR+ gageewere read. It

can be deducedthat thesereeidualetreaeeffectefrom the fabrication

procesewduldmateriallysffect the unit etrainconcentration,=eulting

only fron the supplicationof load.

The SR-L gage givingthe highestuni,t,strain~adings .=.slo-

catedon a flame-cutedge In the case of the unpeipforced.plpi,ee.emd the

plateswith insertplatereinforcements,on a weld bead In the.ceae.of.

the plateswith doublerplatereinforcement,and on a l/4-i9:faC.ehar,,,

immediatelyoppositetwo fillet-weldbeadsin the caee of the platesw$th,..”.

face bar reinforcement.The residualstrainsresultingfxvm the cw!l?ina-

tlon offlame-cuttingend weldingw@d ~troduce uncertaintyinto the

readingsof thesegages. ,.

9. Deformationand Fractureof Plateswith Ooenings.

The twenty-threespecimene,both the plainplateeand the plates

with openings,fai~ed‘with’a completelyductilefrscturein the room

temperaturetestsrepotied“herein.Semi ~escriptionof th6 mannerof

failurewill be givenin”the followirigparagraphs.

The plotsof the‘loadsgainst“tk averageelongationon the

36-in.gagelengthshoti”~ Figs.“’35to 39, inclueim’>were all verymuch

the samein ebspe. TN over-allbehsvlorof the ratherlargeregionbe-

tweenthe 36+n. gagellnbs’was”similarin all the speclm&a. However,,..

-26-

in much smallerregions,especiallyaroundthe opening,the smnner

deformationdifferedceneidereblyamongthe variousspecimens.

of

‘l!ahle7 comparesthe load at whichgeneralyieldingof the

platesbeganwith the loadet whichyieldingfirstappearedas evidenced

by Luderslines. ‘Whenthe locationof the‘firstLudersllnesis shown

insidethe openingin Table7, the Luderslinesapp”sredon “thecircumference

of the opening. TheseLuderslineseppeeredin Specs.No. 8, 10, and 22

at loadsequalto about20 percentof the loadat generalyielding,in

six otherspecimensat, or justbeyondthe loadat generalytelding,and

in the remainingplates@th openingeat a load between50 end 100 percent

of the load at generalyielding. The resultsof the SR-4 gagereadings

recordedsmellamountsof plasticstrain,at loadebetween30,000and

60,00C lb. These variousobservationsfoundsmallamountsof plastic

deformationocc~ring in the plateain the rsgionof the openiDgst 10ads

belowthatnscessaryto causegeneralyieldingof the’specimen.

The sketchesin Table7 shov the pointswhPze the maximumunit

strainconcentrationoccurredsnd the firstLuderslinesappeared. In

general,it may be seenthat the firstLuc+’slineswere locatedat, or

very closeto the pointsof maximumunit strainconcentration..,

Figs. 52 to 72 showedthat the shape,of the unit.strainconcen-

trationcurvesaroundthe circumferenceof the openingwas somewhatalike

for the plateswith squareopeningsor squareopeningswith ro~ded cornersj

but completelydifferentfor the plateswith circular,openings. These,.

differencesin straihconcentrationwere also indicatedby theStresscoat

analysisof the reg%onsrotidthe opening. Fig. 73 showsthe resultsof

-27 -..

thisahelyais for the thied~’ o+ ‘o~ningeiti“pl&.eawltheutr6in-

‘‘~oticeinent.The crackingof the Stres&oat delineated”th>”’ertiagof high

“strainafor 6ach load. It may‘b seen in Fig.“73“thdttiii:”~nt of the

“’crack’patternhas been ehownfo??”’each”load‘d “th& the regioiiof high,.

‘“”etraincoveredthe leastarea in the plateswittithe“’”a@re“kpe~$ngand,.

th; moat area”in the platee&th ‘“thecircularopening. The arid‘ofthe

highlystrainedregionearouxidopeningIncreaeeda“s“the&o&er radiusof

the openingincreased.

.lfter’:klevanof”the”plateswith‘6~e&rigsh~d paaeedthe load at

,,,.which generalyieldingbegan,tliecircumfetianceof the opetiingIn the two

,....

regionsof compression““”i~kin‘beg”anto buckle”latarally. Pi~togiaphaof

this IxicklhdecfgeOf the“$@&rigare showniriFig. 74 for plates“&th the

differentQqieaof re$tiorcement.The directionof thislateralde~e~- )

tion was sltiaysopposfteto“thedirectionin wti”chthe sp6cimenaa’a’whole

was ‘slightly“dished““~’tie:distortionresultingfrom the welding. The,,

distance”betweenthe‘hbdal”polritsof’!th&’bucliied”’“edgeof the openingwaa

greatestfor the plateswith’Equ&k “openings‘Andleaetfor those’“withcir-

cularopehings’“andvariedfrom”a lengtheqtiito’‘abouthalf:“o*the“~otal.... .. .... .

width of the specl’menin’‘t&”’case of’tbe’aqui+re”“openingto a leti@hatime-

what long~”r”than the’”w“ldthof”t“ha“&pe&ngin’the caseof the;c~r~ar

opening. “’:,..

The”folleiiing’~lai& buciiledlaterally irL”thou~Te’&orcernekt,

Specs.No. 2,”33““”and&; with doubler””plwterklhorcement;S&cs. No. 11”

to”’16? inclukik; and with”insertplate”:rei&okc&efi~YSpecS.No’:20”‘and’‘

22. All’of the ep%blmenswith double?$lkterel~orcehn{”&d ‘two:of’,the

,’~’

,.

-28-

SIX.specimetiwith insertplatereinforcementbukled laterallyd~i.w

loading. i?oneof the plateswith face bar reinforcementbuckledlat,erelly.

A comparisonofthe load on the specimenand the,maximumdeflec-

tion of thisbucklededge is shownin Fig. 75. The lateraldeflec~on..in-

creaeedas the loadwas increased.i~hen~ ~Wves in Fig. 75 were extra-

polatedbeck to zero deflection,theywere foundto intersectthe vertical

axis of the diagrnmat a loadapproximatelyequalto the load atgeneral

yielding.

Elva of the elevenspeclmenawhichbuckledleterallybad ultimate

strengthsexceeding~, COO.~i. Four of the nine apecimsnslisted.In

Table6 as givingthe best performance,buckledlaterally.NO indication

was foundthat this lateralbucklingo.f.tha,edgesof the openingunder

compressionstrainbed any significanteffectupon the ultimatestrength

or the en+rm absorptionto failureof the plateswith openings..

The firstcrackor the b?ginqingof fractureappearedat ~he.

me@m~ load,in the plateswith openings,and the load thereafterfe~ off

.a~.ths fracturetraversedthe widtho? the plata. An exception+0 this

behati.oroccurredfn Specs.No. 8 end 13, in whichs@l .cra@cs.appeared

at the c,ornera,of the equaraopeningat 97 percentof tba ultimateload..

The sketchesin.Table7 show thatthe fractimebeganat the pointsof

maximumunit strainconcentrationin everyapeclmenexceptSpecs.No. 7,

9, and 22, in which the ~itiel fractureoccurredby shearin t,heweld

betweenthe bodyplateend the reinforcementat a pointadjacent,to ~e

locationof the mximum unit strainconcentration.The ~cture st++ed

in all the plateawith openingsat, or ~ry near the pointof meximum

strainconcentration.Moreover,the firstLuderslinesappearedIn the

same regions.

-29-

.,Piiotograph6of the specimensafterfractureare shownin Figs.76

to 79, inclusive.The fr~ct’m”beganat the edgeof the opening,psssed

throughth6”relnforceuentat its narrqwestwidth,and then continued

horizontallyacrossthe plate. An exceptionto thisbehetioroccurred

in Specs.No. 7, 9, and 22 whichfailedby ahearin the weld betweenthe

body plateend the outeredge of the reinforcement.In thesethreeplates,

the reinforcementwas lsft intactand the fracturepassedaroundft. In

none of the testsdid the spechen breakcompletelyin two halves,and a

smallpart of the cross-sectionwas alwaysleft intact.

After the frecturehad beguntu traversethe widthof the plate,

observationsof the load on the specimenand the totallengthof the

fracturewere takenat intervalsuntilthe fracturereachedthe outer

edge of the specimen. The readingsof the loadand the progress.of the

fracturewere plottedas shownin Fig. 80 for eighteenof the plateswith

openings. It was foundthatthe load on the specimendecreasedapproxi-

matelyin a linearmannerwith the totallengthof the fracture. In a

rethercrudewsy thisdata indicatedthatthe loadwhich the partlyfrac-

turedspectmencould

brokencross-section

oarrywas proportional

areaof the specinen.

to the totalremainingun-

10. BriefSummervof theExperimentalResultsof the Testsof PlainPlateqand PlateswithOoenines.

Beforethe resultsof the testsof plainplatesend of plates

with openingsare discussed,the more importantexperimentalobservations

of the investigationwI1l be summarized.They are as follows:

1. All the plainplatesand the plateswith openingseuatained

completelyductilefractureain testsat room temperature.

<..

,

.

,,:

,,.,

-,,. ...

.

. ,.,,,,.. ,

,,

-30-

The averageelongation.tmfailureon the 36-in.gage length

for the plateswith openings,~$ed ,from16 to,36~egt,“,of the averageof the valqeefor the,,twoplain.plate,e.Ths

:!y,’. ~.., ..’’.’.:’”plainplataeunderwentapp@xi~tel.ythe samea~ount,:of

elongationto failureae the much e@ler tensilecoupons.,, .,

All the plateswith clrcul.aropeningsor with equereopenings

with roundedcornereunderwenta greateraverageelongation

to feilureon the 36-in.gagelengththan any of the platee

with squareopeninge.

The evaragenet stressat generalyieldlngof the pletes

with openingsrangedfrom 36,360to 45,500pei end may be

comparedwith the averagefor the plainplatesof 42,880ps1

end with the averagefor the tensilecoupontestsof the

l/,4-in.plat%sof u, 500 psi.

The ultimateloa~ sustainedby the pl@,eswith openingsin-

creasedin directproportionto the logar~t,hmof the a-rage

elongationto ultimateload on the 36-,in..gagelength.,’..

“Theultimateload sustainedby the plateswith openings,.variedfrom 61 to 95 percentof the ultimataload sustained

,-.’”by the two plainplatea.

!~’?~t?p$? :etK@ngth‘d.the pla~a:iwlthopenin~ yaried,..,-.,.,,~<.,- ‘,.,

from47,690to 67,800,psi,or from:ap~ro+mately.75 to 100.:

‘percentOf the ultimatestrengtho?,the.plainplatesand,,

the tensilecoupone. :,,.,,, ..... ....

, ,.. ,,.

-31-

8. The ultimateload and the ultimatestrengthof the plates

with openingeincreased$n the orderof the dape of the

openingas follows: eque~, squarewith roundedcornere,

and circular. The etrengthwee effectedonly to a ssxd.1

degreebg the type end the @sountof reinforcement.

.9. The ultimateloed increased,but the ultimate@rength de-

creasedfor the plateswith openiogeas the percentageof

reinforcementIncreased. The rate of increaseor decrease

was aboutthe camefor the threeshapasof openings.

10. The ultimatestrengthof the plateswith openingedecreased

in a linearmannerwith the logarithmof the ratio,R@H,

where~ was the half-widthof the openingand RNtiBcorner

radiusof the opening.

11. The energyabsorptionto ultimateload of the plateswith

openingsrsr.gedfrom 6 t.aY+ percentof the same valuesfor

the plainplates,whilethe energyabsorptionto failurefor

the plateswith openingevariedfrom9 to 26 percentof the

ssmevaluesfor the plainplatea.

12. No clearr.elationahipbetweenthe energyabsorptionto failure

and the,percentageof reinforcementwae foundfor the plates

with openings. No sizeablechangeIn the energyabsorption

to failurewas broughtaboutby increasingthe percentage

of reinforcement.

13. .Th?logarithmof the energyabsorptionto failureof the

plates@th openingsdecreasedlinearlywith the logarithm

of the ratio,RdRN.

-32-

U.

15.

16.

17.

18.

19.

The specimenswhich gave the bestperformancewith reepect

to theirstrengthend enarw-absorbingcapacitywere those#

plateswith ,circvlaropeni~s or with squareopeningewith

roundedcor!@rs,whilethe pleteewith squareopeningscon-

eietentlyg~vethe worstperformance.

The nine plateewith openingsgivingthe best performance

includedtwo epecimenswith face bar reinforcement,three

with insertplatereinforcement,and fourwith doubler

platereinforcomerrt.

The performanceof all the plateswith squareopenings,

eitherreinforce~or unreinforced,was inferiorto thatof

the unreinfercodplateswith circularopeml.ngeor equare

openingswith roundedcorners.

The plateswith openingswhich sustainedthe highestult-

imate loadend the highe8tultlmateetrengthalso abeorbed

the greatestamountof energyto fallure.

In a very abort‘dl.stancealongthe circk”erenceof the

opeaing~n the vicinityof the cornerof the opening,the

unit etrainafor the twe typesof equareopeningdecreased

=m rnpfdlyon ~th sidesOf the peintof the maximum

temion value. The slepeof the straingradienton each

aide of the pointef the maximumtensionvaluewas very

gradualin the case of the circ~ar opening.

The majoreffectupon the unit sti’abdistributionof

addingreinforcementto the @.ateswith unreinforcedopenings

-33-

t

,

1.

,,

.,, .:

20.

.21.

,.,.

22.

23.

.

ma te.~?~.p ,tk,~gnit~es of the unit s,traiqain the

~t!$?n~. t% OPS~nS and reducethe magnitudesnear the

outer.edge~ the plate. .,.

.Thereaidm @raine resultingfrom the fabricationpro-..

cess made eny quantitativeanal~ls of the observedunit

atralnsdlfficolt.

Luderslinesindicatinglocalyieldingappearedin SOIDS

of the plateswith openings,at loadsequalto approximately

20 percent.of the load requi~d to bringaboutgeneral

yieldingof the speclman.

The yea of the highlystrainedregionsarpupdthe opening

ipcreaeedas the cornerradiusof the.openingincreased.

The locationof the firstL@ers lineeand the pointwhere

fracture.s.~rted,wer,eat, or very near,the pointson the

circumferenceof the,open@g wherethe nmximumunitetrains

were measumd.:.,

N,o.i~icqtlpn was foundthatthe lateralbuckllngof the

edges.of the..openingunderc.impression,strainhad any sig-

nificanteffectupon the ultlm,atestrengthor the energy

abew@.ion to failureof the..p~ateswith openings. ,

VI. DISCUSSION‘“bFi+ilSULTS

GeneralYielding..Qt@nateStrength.and“Enerey Abeomtion of PlainPlatesand Plateswith @e nin.qs.

Plastlcdeformationoccurredat 10W.loads,in smallregionsof

$,he.plat.esw$th openingsin the vicinityof the cornersof the opening,

“-34-

whexw tbe.,~glpq~nnlt etrainc%omcentrattouwas found. Sincetheseregions

yere vp~,,.qme~,@ area co-~ .to& mhol~ ~ecimen ha ehownIn Fig. 73,.,,

the effectof thie localizedyieldingupbh“.thwelopeof the load-average

s~a~on curveIn its,earlystsgeswas not verygreat.

..... .. Whilethe highlystralnad.I@ons in the plateswith circular

openingswere locatedat the two oppmit,asidesof:the bpening,there

were four:regionsof highstrainat the four cornersof the”‘twotypesof

squa~ op@ng. Althoughthe initiationof yieldingoccurredIn quitea

differentme~er in the pleteewith equareopeningsand’squareopenings

with roundedcornersas compaxedto ths plateswitk elti~ularopenings,the

effeetof this,I@e,aliFedYieldlngIn producinga point of generalyield-

ing in the spe#ugm as a wholv,wss apparentlymuch the camefor all three

ehapesof oppning,because.all thetieplatessustainedan averagenet

atreeaat -g+nerslyieldingof the wholeplatewhichwas equalto, or some-

what 1sss,thanthe averagestress.at n~h theplain platesyielded.

The ultimatestrengthof the platde“XKtthopenlngedecreasedin

s linearmsnneras shownin Fig.45 with the“~ogtztithof the ratio,

R@N~ whereR@hs the half-widthof the openingand ~ the cornerradina

of the opening. A similarrelationbetweenthe ultimitestrengthin the

wide-platetests(1) and the acuityof theirnotches”*as foundand is

shownin Figs. 81, 82, and 83. In theseteststhe thickneaeof the plate

was 3/L in. and the ratio of”the widthof the openingto the widthof the

epeclmenciib-fourtli,’””iddle‘“th6~dth of,the epecic,enewas ~aried‘XromX2

to 72 in..The,notchradluaremainedoonetent. A plct for a similar

seriesof ~ts. .(2.)is ehownin Fig.:84. The thickness’~ ‘thawidth ‘

t

1, 2. Thesereferencesappearin the Bibliograp&of AppendixA.

.

-35-

of the plateremainedconstantfor the8elest testses well as the value

of one-fourthfor the ratioof the widthof the openingto the widthof

the specimen. The notchradluawas varied. The samereletfonbe-en

the ultimateetrengthand the aoultyof the opaningwae feud In theee

wide-platetietsae was observedin the teetereportedherein. unfortunate-

ly, otherteeteof structuralstaelplateeIn wbiohthe type of speciuen

more nearlyresembledthe plates

not found.

It Is Interestingthat

pointefellinto a bend,and the

of cleavagein the fracturewere

withsquareend oirouleropeningswere

In Figs.81 to 84, inolueive,the plotted

epecimenewith the greaterpercentsgee

locatedat the bottamof the band end the

epecimenswith mmzllerpercentagesof cleavageet the top of the band.

The ultimateetrengthof the pleteawith openingswae related

to the acuityof the notch. A somewhateimilarrelationwee foundin

Fig. 48 for the ener~ ab@orbedto fallure. The logarithmof the energy

absorptionto failuredecreasedIn a linearmannerwith the logarithmof

the ratio,~~N. Sinoe the valuesof the energyabsorptionfor the wlde-

platetests(1) dependeduponthe size of the spacimeneend couldnot

easilybe reducedto a commenbasisof comparisonend,moreover,because

the energgabsorptionto failurewee not reportedfor the otherquoted

tests (2),no corroborationof thesafindingsof this Investigationcould

be made.

The relaf,lonsfn Figs.45 and 48 betweenthe ultimatestrength

and the ene~ absorptionto failureon one hand and the acuityof the

-36-.,.,

openingon the otherhand indicatedthat the notch-affectof,the opening

waa“rimeeffectivein reduchg the enar&yabsorptionthen the ultlmate

strength. The ultimatestrengthof the plateswith oponlngsvariedbetwe~

aPPrommately75 and lW peroentof the strengthof the plalnplatee,but

the energyabaorptj.onto failureof the formerwas only 9 to 26 peroent

of the same valueafor the latter. Whilethe ultimateetrengthof the

plateewith openingsapproachedthat of the plainplate,the energyabeo~

tion te failureof the formernewerwee but a emallfractionof the energy

absorptionof the latter.

The relationsexpreeeedin Figs.45 and 48 protidea meansof

pred.ictlxgthe po+~ntialultimatestrengthand the encu’gyabsorptionof

apecinenswith the aarcerelativewidthof openingand the cametypeeof. .

reinfcrcemantas ‘LAosea’lread:~tetited,but with differentshapesof

opening. In particular,thesefigureecouldbe tt.edfmr plateewith. .

squareopedngs with roundedcornerswherethe cornerradiushad a %WAIUS

othertkn O/g, the ra&ju9used In theee$ee@. ,.

Some corralat.’mnwas foundbatwoenthe dietrlbuti@pof the ,pnlt,..

strainsmeasuredin the elaeticrangeof the eteeland thefinal fracture

of the specimen. The pointeon the circumferenceof.the openingwhe~ .:,.

the maximumunitstrainin the elasticrangeof,the spcirn?nwas maaewed,.

were alsothe camepointswherethe firetLulerelineeappearedax ~.@, ?r

nearwhichthe fracturesubsequentlywae inifiated,

The ultimateetrengthof the @t plq+~s.yith o~@n@, waq W@.,

to thatof the plainplateeand decreaeedfor the

openingsin a logicalmannerae the aauityof the

poorerplataewith

openingincrsaeed,It

“-37-

seemedreasohaUe w concludethat‘theiiithl reeidualetrainaand die-

1 tortlonafrom fabrloatfcmiby ‘w61d@ had nO “e@Lficent effect~on the

ultimatestrengthof th6 plateswith arc-weldedrehforcement.

2...Effeotiveneaeof the ReiMforce&nt.

When the lnveetigationwas begun,two criteriawere arbitrar-

ily selectedaa the meansof determiningthe perfoimanceof the plates

with openinge,’the “iltimatestrengthor ultimateload and the energyab-

sorptionto failure. The remlte of this inveatfgetionIndicatedthat the

plateswith openingswhichsustainedthe highestultimateloadsmd the

highestultimateetrengthalso e-beorbedths greatestamountof energyto

fsilure. This lastatetementmust be carefuliylimitedto applyonly to

platesundergoinga “completelyductiletype of fracture.

The designof the nine specimenswhichgave the bestperformance

will be exemined. The threetypesof reinforcementwere representedin

tinethreebeet specimens,Spece.No. 5, 11, and 18, and these threeplates

all had circularopenings. However,plateewith squareopeningswith

roundedcornerscame closelybehindthesein performancerating. It iS

interestingthatnone of the threespecimenswhichfailedby shearin the

weld at the outeredge of the reinforcementwere includedin this list

of the bestepeclmens. The limitednum@r of testsmade suggeetedthat

possiblythe best plateswith openingewere thoeein which the combined

effectof the shapeof the operiingand the type and ammnt of reinforcem-

ent was justsufficientto preventa sheerfailureat the outerboundary

of the reinforcement.This conclusionmay be contradictedby subsequent

tests.

-38-

Ths ~rformanca of all the platesti.thsquareopeningswas poor

in comparisonwith the platqswith the othertwo.shap6s”‘oSopeiiib@.“In

fact,the reeultsof theeeWs.@ s&wad.tiiat.an.uhrelhfoicA”- ‘:Witi

a circularabspeor a squareehapewith ~ound~dcornefe‘@vi.ng..ti.clnmsr:

radiugof D/8 was to be preferredto any of the.s<tire”6@n@s; whether

reinforced,or nnreitio~~d,~

Some oommentehouldbe made aboutSpec..No.”19 whichhad the

loFestultlmstestrengthof;all the plates. A sketchof this specimen

is shownin Fig. 5..,It;e~e~ poseiblethatt~e net wSdthof the rsinforce-”

ment.at the,cornerswas reducedin thts specimen&y@ the minimumde-

sirablewidth. Pe~hape,.an,iqaert,plate‘oflsrgeidiameterwouldhave

substantiallyincreased,.the ,etrengtb’of this epacfbn.’

,Theul~mate load Imcreased,but the ultimateetrengthdecreased

as thepercentage.ofrei=eorcezmntwas increae~. The greaterth’@r-

cent,ageof reinforcement;the leseeffIcientthe‘?einfor’cemeritbecame.

This ree.ult.of theseteetswae in accordwith tha Predictionsof thaory :

(16).

No clearrelationshipbetweenthe anerggabsorptionto failure

and the prcentage of reinforcementwas foundfor the plateswith openings.

No sizeablec@nge in the energyabsorptionto failurewas broughtahout

by increasing,the percentageof reinforcement.Fone of the typesof rein.

forcemsntused..+ntheeetestswas effectiveIn increasingappreciablythe

ener= absorptionof so unreinforcedplatewithan opening.

From the resultof thesetests,someeatimatacouldbe made of

the bestpossibleperformanceof a platewith a reinforcedopaning. While

the averagenet stressat initialyieldingof the plate ae a whole and at

-39-

ultiqate.,strengthwouldapprnaoh,or equalthe seasTsluesfor the plain

plate,the.energyakmorp’donto failmrewouldprobeLClynot exceed15 or

20 percentof that of the plalnplate. ,.

VII. CONCLIEIONS

Room temperaturetestehs~ beenmade of two plainplateewithout

openings,threeplateawith unreinforcedopenings,and eighteenplates

with arc-weldedreinforcementaroundthe opening. Three typesof welded

reinforcementwme Inveatigatedzface bars,”singledoublerplstee,and

insertplates. The plateswithoutreinforcementend thosewith sach type

of reinforcementwere fabrlcatedwith threed%fferentshepaaof opening:

circular,squarewith roundedcorners,and equsrewith

two of the twenty-oneplateswith openingswere alike.

of’any of thesespecimenswouldundoubtedlyhave given

ebarpcorners. No

Duplicateteste

somewhatdifferent

resulti.

All thesetestsresultedin completelyductilefractures,and

all concluaionemust be limitedto thiskind of fracture. The reaulteof

the presentseriesof teatsappearto justifythe followingtentativecon-

clusionswith reepectto the plateswith opanings:

1. The open~g was many timesas effectivein decreasingthe

energyabsorptionof the platesas theirultimateetrength.

While the ultimatestrengthof the plateswith openings

variedfrom75 to 100 percentof the valueefor the plain

platesand he te~ile coupns, the energyabeorptlonto

failurevariedfrom only 9 to 26 percentof the valuefor

the plalnplates.

3.

,.. ,

;’

i..,,

.,

.. .

-40-

Arc-weldedre%nforcemntIncteaaedthe ultlmetaetrehgthof

the plates,but Zr@ght aboutno noticeableohangeiritheir

energyabsorption. c

The openlngeand tlw reinforcementdid not appreciablyin-

fluencethe generalyielding. Localyieldingoccurredat.,:’verylow loada,but the averagenet streesat general

,.

yieldingof the platesae a wholewas approximatelyequal..

to, or .elightlylese,than the tensilecouponyieldpoipt.,,

The specimenswhichgave the b.es,t.perfo:mencew$t,hrespct

to theirstrengthand energy-abeorbingcapacitywere thoee

plateawith circularopeningeor with squareopeningswith....:, ,,.

roundedcorners. The nine platesgivingthe best pe,rfo,~..:.

ante includedtwo,apecimenewith face bar reinfoz’ce~nt,,.

threewith insertplatereinforcement,and fourwith doubler

platereinforcement.,,

VIII.ACKNOWLEXIEMENT

The investigationreportedhereinwaa sponsoredby the Ship

StructureCoumdtteeand waa carriedout in theStructuralResearchLab-

oratoryof the Departmentof CivilEngineering,Univareityof Washington.

“Thecostof the supervisionand the instrumentationwas aeaumedby the

EngineeringExperimentStation. The teetprogramend the preparationof

the reportwere underthe directionof Dr. R. A. Hechtman,Aesociete

Professorof StructuralResearch. Dr. D. Vaserhelylwas the project

-u-

engineerand was aselstedby Mr. K. J. Kenworthy.

laborsterystaffwho tookpart M the work ware as

A. K. Chin,Mrs. Ione Knlekern,J. J. Miles,C. W..,

The authorsare gratafulto ProfaseorF.

othermembersof the

followe: H. C. Cheng,

Norton,and Z. Swystun.

B. Farqubweon,Di.reo-

to$~EngineeringE~ehnt Statlon~?or hleencotiragement~&d” s~gistiarie

and to Mr. A. B. Jacobsenend Mr. L. D. Bsrterof the ElectronicMeeeure-

ment and’ControiLiib6ratoryof theEngin&eringExperiment$tati’o”nfor ““

providingthe instrumentationused in thesetaste.

. . .,.

-&2-

,. ..,.

. . TARLEI ~~

.l@CRANICALPROPERTIES03!PLATESOF DIFFER3NT. ..., ‘ltlI@N@S. SEMI-KI13EDSTEELU AS ROLLED

,.,....:: ,.: :,’.

Plate Tt@ck- Upper Uj.tinmte Elongation Rediiat.ion““’NO.’ ‘ ness Yield Strength in 8-in. of Area

Pointin. DSi net Der cent Per cent

~(j . 1 32,800 61,100 32.6 55.6

25 1/2 36,500 61,100 31.2 54.0

16 l/L 44,1OO 65,300 29.5 50.9

17 l/.4 449300 65,200 29.4 51.7

18 1/4 45,100 65,800 29.2 50.8

19 1/4 &ooo 65,900 28.2 51.7

20 1/4 .44,700 66,000 28.4 49.5

21 1/4 4.&500 66,000 28.6 50.2

22 l/L 43$~o 65,600 28.9 49.6

23 1/4 45,4W 66,100 30.4 49.8

24 1/4 44,s00 65,800 29.3 49.6

Tensilepropertiesare awrage of resultsof two testsof ASTM standardflat tensilecoupone.

-- 143-

TABLE2

DECRYPTION OF SPECIMSNSWITH l/4-IN.BODY PIME*

spec. ~ Size of PeroOntage CrOas-SectionNo. Reinforceusnt of

Radius Reinforce- Groes Netin. ment

1

23

2

:

i7

;10

11

?3u1516

171819202122

?~i n Plates

None -- , .’-- ,XK 9.(Y7 9.07None - - -- lCQ 9.1-4 9.14

Plateswith Ume inforoedOMninm

Clrouler - - .- 0 9.21 6.92square 1/32 -- 0 9.18 6.82Square 1-1/8 -- 0 9.15 6.87

Plateewith CBenfnm Reinforcedkm a Face E!aE

Circular - - 2ktl/4° 40 9.1.1 7.76Circular - - l“xl/4° 9.15 7.25Squsre 1/4 2nfl/4fl z 9.11Square 3/16 l“il/4°

1-1/816 9.02 ?:

Squsre 21tfi/411 40 9.13 7.74Squsre 1-1/8 l%zl/4° 16 9.15 7.22

Plateswith OmeninpsReinforcedbY a Slnale DoublerPlate

Circular - - l@lD*fi/4tl 102 9.11 9.13Circuler - - 13-1/2’’D.xl/4° 50 9.14 7.99Square 1/32 l@lfignfi/4tt lo4 9.17 9.21Square 1/32 13-1/2’’x13-l/2Wxl/4° 51Square

9.I.41-1/8 1811fi!3t1fi/4n 103 :::

Square 1-1/8, >>1/2’’fi3-l/2mxl/4n s.:: 8.01

PlatesWith ODenius Reinforcedby an InsertPlate

Circular - - 12-3/4*’D.fl/2‘1 39 9.11 7.71Circular - - 10-1/2’!D.xl[J 50 9.13 8.08Square 1/32 15ND.xl/2’t 9.04 7.55Square 1/32 12.3/4’’xl2-3/ti#2‘t ; 9.13 ?.72Square 1-1/8 151’D.xl/2’t 62 9.02 8.17Square 1-1/8 12-3/4nx12-3/4”xl/2” 39 9.04 7.66

* All teetsmade at room texpratvre.

-l+-

-.-., - ....-”.”-. . . . . . . ,-

r ,,, -.7:,... ,. :;, .-.: ,..TAME 3

.: !:. .-: ,,,,.,,.,.1 ,

LIST OF PLAX3SBED FOR-.----......... ....... FASRICATI~TOF EACH SPECIMEN

Spec.,,.,. No. of PlateUsedfor., .,.” No. Se&v P3.ete* %etnforoeugn~,,... .,,.,*...:.,

.....,,,. <.,., ,.. . .~:.”,-. , .’.,:. ,.

Ii

. ...,..,,,,.,

,. ,.

.: :,. “

. .:-.. .

. .

12

18

i?22222120212016221719

20

222121 ,212121251025

* Mechsni,cdpropertiesof plateegivenin Table1.. Sketchesof specimene“InFigs.2-5, Inclueive.

., ,..,,.,,

.,., ,.

.. ,.

. . .. .. ... . . .

, .

TASLE4

STPJINGTHAND ENERGYASSOP.PTIONOF l/4-IN.pLAINp~~s ~TD p~~s WITH O~~NGs

Spec. .ooenl~ PercentageTest.. General Yieldinp UltimateStrendh EnergyAbsorption....No. Shape Corner of Temp. Load AverageStress Load AverageStress in 10GfJ~s,in-lb+

.. kdius Reinforce- Deg. lb~. Oei lbs ● DBi To Ulti- TO

in. ment F. Gro8e Net Groee Net mata Load Failure ‘“’‘”

1 None -- 100 81 380,000 “ 42,200.42,220 588,500 65,390 65,390 4,01fl 5,276. ... .

23 None -- 100 76 390,000 .43,330. L3,330 583,000 64,’780 “&i,7so 4,062~,ti.. ?

2 Circular- - 0 76 291,500 32,40Q 43,2004.40,00048,900 65,15o 1,136 1,1(4

3 Square 1/32 o 72 292,000 32,500 L3,250 357,500 39,800 52,900 338 y%,..

4 Square 1-1/8 o 78 292 ,COO 32,500 43,250 421,0Q0 46,700 $2,350 n?., !%;

5 Circular - - 40 74 32&,000 , 36,000 42,500 517,000 57,400 67,S00 1,277 1,420 ,! ‘

6 Circular - - 17 73 324tom 36,~ 45,500457,000 50;800 64,200 725 910

7 Sq~re 1/4 40 75 322,000 35,800 ,&.,230 j~,ooo 44,100 5+,.yo _.. 422—.. 750 -,. .—

8 squre ..3/16 16 74 288,CO0 32,(2QO 40,420391,500 h3,500 54,950... 447 7m .

. .9 . ?q?w 1-1/8 40 ,W 319,000 35, 500-::ZI=%9.431,00C 5%100 5%150, ___.. 747.

~,063.’ ‘.....-.

10 Square 1-1/8 16 75 313,000 34, s00 43,930467’,000 51,Wo 65,54~ 1,234 1,504 ‘.

11 Circular -- 102 75 360,000 40,050 40,050555,000 61,670 61,670 1,358 1,569

1.2 Circular - - 50 73 331,5CKl 36,9oo 42,100488,000 54,200 62,0Q0 m 983

13 Square 1/32 104 76 337,500 37,500 Y7,500451$500 50,170 50,170 3s7 728

... ., ,. ,. .._ ,.. ..N,. .... . ..

TABLE4 (Cent, ),,,

STRENGTHANOENERGYABSORPTIONOF l/4-IN. PLAIN PLATESANDPLATESWITHOPENINGS,,:.

,,. .

Spec. &x?ninE Percentage l’est. ~~~e~~~~$:~z~ UltimeteStrenvth EnergyAbsorptionNo. Shape Corner of Temp. Load Awrage Stress Lead Average Stress h

~~’Radius Reinforce-’ Deg. lbs~1000 Is in-lb<

Pslin,

lbs , Oei To Ulti- ~0ment F. Gross N2t Groes Net,, mateLoad Failure

14 sq~re @ 51 71 3oo,ooo 33,3130 38,100 406,0wI 45,1oo 51,6JJo 328 621,,; .

15 square 1-1/8 103 76 362,000 40,220 40,220 522,500 58,0fXI 58,060 729 1?099

16 Square l-1/8 52 73 3oo, om 33,300 38,100 UY7,000 54,100 61,9oo 779 1,154 ;

;7 Circular - - 39 74 322,000 35,mo 41,86 495,60o 55,000 64,390 1,196 1,361. I

18 Circular - - 50 75 340,000 37,800 43,200 521,50C”” 58,000 66,300 1,266 i,400

19 Square 1/32 33 76”’ 3ol,o@3 33,Am 39,660 362,000 40;hO0 47,690 “““229 “ 548

20 square 1/32 39 72 320,0~ 35,6QQ 41,620 427,000 47,560 55,540 545 836

21 Square l-1/8 62~~ 77 ..300,00Q33,300 36,360 478,0@ .53,;l~0’,57,940 1~155 1,484

22 Sq,uare.“,1-1/8 39 73 319,0go ,35,50041,490 437,~ ‘“@~IJ 56,S0 00 “-974.,.

,..

.?,,. .. . . .-,’ ,.,

,

.

,TABIE5 .

EFFICIENCYOF PLATESWITH OPENINS AS COMPAREDWITHPLAINPLATES

Spec. Ooeniniz Reinforcement ~EfficiencyComparedto PlainPlate A PercentNo. Shepe Corner GeneralYielding UltimateStrend.h EnereyAbeerptlon

Radiw Load Average Load Averagein.

To Ult, TOStress Strese Load Failure

Plateawith UnrelnforcedOmenings

2 Circular - - .- 76 101 ’75 100 28 19

3 Square 1/32 w * 76 101 61, ,t?2 8 9

4 square 1-1/8 -- ., 76 101 72 96 M 15

Plate8 with 00enines Reinforced bv a Face Bar

5 Circular - - 2ufi/4n Face &r ~ lm ‘ .98 104 32 a

6“ Circular - - 111~/411 Face B= ~~ 1~ 78 99 18 15

7 Sqwre ?4 2%cl/4w Face Bar ~ .,,,99 68 80 10 12

8 Square 3/16 lllfl/LllFace Bar ~ 95 67 S.& 11 13

9.squal%” ““1-1/8 2tI~/411 Face ~r $33- 98 “m. 91 18 ~~.. . .

10 Square 1-1/8 lS&411 Face Ber 81 103 80 101 30 25

flatee with ODeninga Reinforced bY a Sin$!l e Doubler Plate

11 Circular - - 1811D~/4S DO~~er 94 94 95 95 34 26

1.2 Cficular - - 13-1/2 Wxl/4tt 86 98 83 95 19 16Doubler

. . .. . ..... .. . .. .. .

,.. TABLE‘5(Cont.) ~~

EFFICIENCYOF PLATESWITH OPENINGSAS COMPAREDWITH PLAINPLATES.......

Spec. Openinp Reinforcement EfficiencvComuaredto PlainPlate - PercentNo..,,Sbpe .,Corner GeneralYieldin< UltimateStreneth Enerev Abeorotion

Radius ‘ Load Average Load Average to Ult. ~~to, ilk stress “Stres; Load Failure-, ~atea with k ningsReinforcedbv a SinwleDoublerPlate ,, ~~

Squere.,1/32 ~~@:~/4°13. :,,,,. .’.88 “ ‘8$ 7’? “4 ““lo 12

,U ,Squere 1/32 13-1/2’’Sq.x ./L” 78 “’89 69 “86 ‘ 8Doubler

15 Sqllqre -1-1/8 18’’Sqoxl/4!! ~& ; ,,94 89 ’89 18D-otibler

16 -. Squgre 1~1/8 13-1/2’Wqoit/4’r 78 ‘ ’89 83 95 19Doubler . ... .. . .. .. ..

Plates with Ooe “‘&m Reinforced by an Insert Pla~

~~~17 Ciroular. - - 1.2-3/4’’M/2n &$ ; “98 84 ?9 ,30Insert

.18 Circular “..- - 17j-@mn ‘%8 101 89” 102 .31Ineert

:19 squab ?/32 15Nti/21!Insert +8 ., $?.,., 62 73 6.

20 square 1/32 12-3]4ifsq.xl/21*63 97 . ... 73, ,...85...... 14.Ineert ~~

2X -Sq~~ ‘“-”’~R1/8’ 15Wxl/2ttIneert 78 85 82”’ 8,.29

22 Square..lrii/8 12-3/4nSq.ti/2° 83 97 *.. ..... .i5“75 ““’” ‘“”Insert

10

,1~I

19 “em1

22

.,23

9

,.. .U: .

25

“16

TASI.E 6

TYPES OF RRINFORCEWNTGIVINGTHEGREATESTEFFICIENCIES FOR PLATE9WITHOPSNIWS SUSTAININGCOMPLETELYDCCTILEFRACTURES

Spec. Shape of Opeoing Reinforcement Percentageof EfficiencyComuaredto PlainPlatNo.

e-PerReinforcementLoad at Ultimate Ultimate Energ

general Load Stren@ FailurYieldirw

5

10

11

12

15

16

17

M

21

Circular 2bl/4t~ Face Bar

square , lW./4tf Face BarRounded Cornere

Circular 1811~411 DoublerPlate

Circular 12-1/2 nDd/4’tDoubler PMte

Square, lgWq.xl/4n DoublerRounded Cornere Plate

Square, 13.1/2 Wq.xl/4*1Rouuded Cornere Doubler Plate

Ciroular 12-3/4Wxl/2n IneertPlate

Circular 10-1/2 nDxll~ InsertPlate

Square, 15’UMl/2!l Ineert PlateRounded Corners

Maximuma for all Specimene

40

16

102

50

103

52

39

50

62

103

84 88

81 80

94 95

86 83

94 i+

78 83

% 84

88 ‘9

78 82

94 95

104

101

95

95

89

95

99

102

89

104

24

25

18

19

22

23

25

26

-50-

TABLE 7

GENERAL YIFXJIING AND FRACTURE3 OF PLATES WITH OPENINGS

Spec. Load in Kips at Location of First Laders Lines,No. First General First Ultimate First Crack, Maximum Unit

Luders Yielding Crack Load Strain Concentratio& snd Later-Line al Bucklin@

--+

,(1111,

2 291.5 291.5 440.0 440.0~“

[,11’

3 220.0 292.0 357.5 357.5

4 280.0 292.0 421.0 421.0

5 324.0 324.0 517.0 517.0

* Legend:

-$51111 Ill

+

1111111

9I

Max. unit strain concentration according to SR-4 gage readings.

Luders lines appearing before general yielding of specimen.

Lateral buckling of plate in regions of compression stress.

Point of first crack.

Fracture.

-51-.

TABLE 7 (cont.) TABLE 7 (cont.)

GENERAL YLELDE4G AND FRACIWRES OF PLATE.? WITH OPENINGS GENERAL YIELDKNG AND FRACTURL9 OF PI.AT=? WITH OPENINGS

spec. ~. ~~~d=’ .!;,: ~:I,x.UO. d First Uders ties, p. bad in KiPs.ak _

No. llltimi(~ First Crack, Maxim. m Unit

mm...4 First Iadem Lines,

Fi% Generzl FirstI,ud,rs Yi.ldlng C rnck Lm.d SJW;:c;g.entratim, and Late, -

Ultir’1.teFir,t crack,MaximumunitLudem Yielding C rack tid SJBS&m&entraUC% and Later

Line u..

6 324.0

‘1

8

9

10

11

12

13

140.0

6Q.O

180.0

6a.o

100.0

331.5

337.5

324.0

322,0

288.0

319.0

313.0

360.5

931.5

337.5

457.0

39’/.0

380.0

451,0

457.0

555.3

488.0

440.0

397.0

391,5

451.0

467.0

555.3

488.3

451.5

14 220.0 3W.O 406.0 406.0

-cl--

@

.,,

3,,

,,,

-Da,,,,,

‘ I “

‘a

15

16

17

18

382.0 382.0

220.0 300.0

140.0 322.0

280.0 340.0

522,5

48’7.0

495.0

521.5

522,5

487,0

495.0

521,5

-+(3,,..$“,..

cl-..,.

19 lW.O 301,0 382.0 362.0 ,-

ml

20 140.0 320.0 427.0 427.0 ‘-+,..

.

,,.

0

,-

21 100.0 3!3+).0 418.0 478.o

\ ,*$-

,.0.:,,-

Q

22 60.0 319.0 437.0 437.0 a?,,-

,& ‘......,4.

-52-

l/f~-h.

Plate

l/2-In.Plate

l-In.Plate

core Rim

Fig. 1. ~crostr,lcturesof TypicalPlatesof Each Thickness LlsedfmSpeci5em. secticms TakenParallelto Directioncf Rollir.g.Magnification2(X)X.NitalEtch.

l“r- 1~

EQUAL SPACING ON BOl+iwFACES OF SPECIMEN

I

/

.—

‘0.;

--—~—--— —

@’Jp!qJ‘-- ‘-”--~R I

-~ ~E ~

Spec. No. 2 Spec. No. 3

Svec. No. 1 and 23

Fig.2. Details of PlafnPlatesandPlateswithUnreinforcedO?enfngs.

Spec. No. 5

–T

–1

wSpec. No. 7

~Jii~ pi!%~Tg,,Spec. No. 8

k1% syec. No. 9

=Spec. No. 10 1%

~.i 1%

Fi~.3.Details of Plates with Owni!w Re~Orced @ I Fz.e Bar.

-54-

—v-—-

I!!3r90” 4

D=

13’”

Sp.iv’igA .

s.ec.F5’l!g

Fig. 4. Detafls of Plates with Op.mfngs Reinforced by a Single Doubler Plate.

--~+

Me0=9” @

I-J

.12%

,+1 IJ$F_J

k-

60”Spec.No. 17

60”Spec. No. 18

Swc. NO. 21

80’” 60~

’62+

60”

Fiz’. 5. Details of Plates with Openings Reinforced by an fnsmt Plate,

-55-

Fig. 6. Typical Specimen Mountedin 2,LOO,OCO-lb. Testing Machineand Ready for Testing.

,43“ 4“——.

TYPE I

I I

AR-1 N

A-7 I

A-11 i

A-12 ~

Fig. 7.

TYPE 2

Locatio-. of SR-4 Electric Strain Gages on Specimens withunreinforced Openings.

,, I

TYPE 3A-7 1

A-11 i

A-12 k

TYPE 4

Fig. 8. Location of SR-4 Electric Strain Gages on Specimens witEOpening Reinforced by a Face Bar.

I,—i94’

l..+

I

~--

9“

L

Fig. 9,

TYPE 5A-II I

‘-12 k

I,,

TYPE 6

Location of SR-4 Electric Strain Gages on Specimens withopening Re~.reed bY a Single Doubler Plate.

L...+L_ k

~.-.-..l.~ ...-j

~-.x ~4’8

““”1””-J6“

6+” ~5“

I...._J J.. i -.,

9“

,, ,,

—4...-L 5 .-

-Y d...~

ri

8“

L

Li .__

5“

TYPE 7

A-ll ;

A-12 ~

- - .Z’A ....4”Jz“

TYPE 8

Fig. iO. Location of SR-4 Electric Strain Gages on Specimens withOpening Reinforced by an Insert Plate.

Fig. 11. msmh.ti.. moss Plate d E1.watim.. 38-in.Gw. L..@z......NO, ,. PM” P1ate.

-58-

3,6

3,2

+

Z.8 — — --l@ —

5 *, ●

i EDOE OF PLbTE:

3 ~, ~ \

8 ~

+

:

~1 ,6

~

I .2

*0

0.8 ,4

W. 0

04

800

291 .s~

0140

F&. 1s mmibutb . ..0s. Plate d EIoI@tio. m m-m-Gag. Lam@=Spin. N., 2. C.=”lar -.

MO ]

p%,

,’

So —4- - T— ----

7.0 ——t + —. -. -

~ ~DaE OF ~&,E

&o +---i -- +

~:

60._t___ –...

1!

?.0

B._.-~oo — -—-— —

460

m420

Saow i0

DIStrltNUOn .,,.,, Plate d E1m@lm 0.98-1- G%, L-@,psc. NC., 23. Pm” Plate.

w. 14. Distrlmn.n ,Crcas Plste .4 m.n@n4n 0. w-m *. 1,.mgth,@c, No. 9, &mue OF-LW.

-s9 -3.6

m

3.,--- .....4 ~.. -.1 ..-

2.8 ..+”j’’oo’:{p’~:+’<

5

F.,. 15. .,s,,,.”,,.. .,,.ss ,,,,, d mm,@,m .“ $6.In. G=,. Len@b.me.....4. W- 0..-8 with !+...ded comers.

F*. 16. Mstributkm %cr.ss Phi. ml E,o.p,,.o . . K. L,. ..,, ,,n@,SF-C. Nm. 5. Ckcul.m cmml,,g. F.., ,., rteimimc, tne.,.

3,

,,

I:.

3.2 –- . . ~ +. ___

: .j=EDGE OF PLATE

,>.

2.8 7’-

I~ .\-

2,4.T :--1 – -

,.2

I

0.4 — —. +.4 ,40 _! –..-

II 300K

o ,40

3.2

2 .e

0.8

0,4

0

.ED%E OF PLATE

,

,91S

3s0

,,0

300”

1

0.4

L--

0

–M!1 .

1

,,0 ‘

–60-

m I

II

3.2; ...__/ -—-. .—.

I I

Z.o

La

,.2

,,~ 19. Distribution ..?.s$ Plate d E1owM.” m 36 -h. Gwe La!8th.Fig .20, M8trlb.u’m across Phi. d moE@tO” m w-h Gage Length.

Sr Nm. 8. S.”=. O,edw. Fm.e 9., R.lmforc.m=iSW.. N.. ,. Sr”are Gwnlw with I&.nded Corners. F-e B=rrm!mlorcemmt.

3.6

3.2

28

2,4

1.6 ~~~

,.2

P,..........;3e0 !

,!

00i~i

340

0.4~ ..-

L SOOK

,400

LWtrlbutim -TW6 Plate .4 Elc.r%atlm o“ 9 O-h. C%- L-@

::,-.,:1. Clmuhr CW!IM. 81n@ EXubler PM. Eeln-

-61..

3.e

s,?.

0.8

0,4

0

I

. . . .———

---1~~~~ ‘,E(IOEOFPLATE“N,,

.-*2 –—— .-— ——.... .—

...—— 4 .——

.,, .5*~ ~ .&0

.,3

;... —=——.. ,

3eo”

~

3.6

3.2

0.8

0.4

0

.

,,,EoGE OF PLATE

~~ -+

,06’

/EDGE OF, PLATE .,,,,

/..\

/4eo .=’

-&.2-

‘HiiEk

m

b. f..*8R

;0

We?of PLATE

2.4 / ‘ \

?-0 *

,.6

420

1.2 / ‘ 1.

OB 890

0.6840 ~

SooII -

0~ —

%-.n. Dlstrlt”nm .Crom Phi. cd ma-n m w-b. Gap Ia@h.?ir. =. DUrtOUUM u.” PW d E1.mti m W-k.. We LO@h.

p.ecb,$r.p:ie~Mr:== .ilbR0Jnd9d Corn*r. SW*SF=. No. 17. clrOJlu OPmlM. I@Jerl Pm. Relnf.rc.mmt.

i

3.s .

M

t.o

M

CDOE OF PLATE

Lo /

\

1.8

1*

**

0.8 A%

**O

0.4 ~\

~—

.&3-

“H&k

3.0

3.?. —

a, /

; “4~ ,.0

5+ EDW OF ,LA’t’f

: ,*. /’g~ /’”

G ,,e I—-+- – - j... —...

0.8 ..~ ——. J._._. .

04

300 .~ I140

0 +

-6k-

1 I I I I I I I 1Iwriivd oi ‘ I I I I I

1 “lln 011 I I I I I F---T

z

I I I I I

1e

I I I

1 m

I I I I I

Im

I I I I Iw—

L ‘NI I

1 z

I I I [ I

Im

iin

I

600

500

400

mnz

g 300

0

3

200

100

02

I

~ SPEC. NO. I~ SPEC NO.23 I II—– -

6 8 10

3

AVERAGE ELONGATION ON 36 IN. GAGE LENGTH- INCHE

Fig. 35. Comparison of Load and Average Elongation on 36-III. Gage Len@h for Plain PlalEs

-66-

W=u-L-l.o010

o

600

500

400

COnz

z 300~

9

200

100

00 u .

AVERAGE ELONGATION ON 36 IN. GAGE LENGTH_ INCHES

1

%I

Fig. 37. Comparison of Load and Average Elongation on 36-in. Gage Length for Plates with OPetigSReinforced by a Face Bar.

I

%I

KSPEC. NO. II

SPEC. NO. 12

SPEC. NO. 13

SPEC. No. 14

SPEC. NO. 15

SPEC.NO. 16I

I I

I\

3

Fig. 38. Comparison of Load and Average Elongation on 36-In. Gage Length for Plates wifi OpeningsReinforced by a Single Doubler Plate.

-69-

m“m

6

Sdl)l NI OVO1 k

-i’o-

‘acd

:

600dx

575 T

~1[S50

525 # &

500;5,

4,6(Y7

II

475❑ 10

~6

450 d 3 ~s

&2 o2

425 8?s!s! ~ _ _ _ _

.14

400 ■’ ,8 1x PLAIN PLATE

375 o CIRCULAR OPENING -—.19

.s .u SQUARE OPENING,

350 ROUNDED CORNERS- —

~ SQUARE OPENING325

3000.7 1.0 1.6 2.0 3.0 4.0 6.0 607.08.0

Average Elongation to Ultimate Load - In.

Fig. 40. Comparison of Ultimate Load and Average Elongation to UltimateLoad for Plain Plates and Plates with Openings.

-71-

%

300 -

200 -

100 -

0-

30,000

I30,000

10,000

0SPEC.NO.

Fig. 41.

—

ill12337813 141929fl 91015

It162122,26 611121718

Load and Average Stress on Net Cross Section at General Yieldingof Plain Plates and Plates with Openings.

1

-72-

600

400

200

0

70,000

50,000

3opoo

Io,ooo

SPE:NO. I 23 3 7 8 1314 19,5

‘- ~~N::::~~56’’’7:~:~

=0SQUARE OPENING SQUARE OPENING CIRCULAR OPENIN

Fig. 42. Ultimate Strength of Platn Plates and Plates with Openings.

..7 ,3 -

6000 OIRCULAR OPENINGo SQUARE OPENING, ROUNDED CORNERS■ SQUARE OPENING

~50 x PLAIN PLATE

01805

500 d7

&❑z I

~1o

~6 ❑9

45 02( ~22

4mm

.14

40 0m8

■?

,193

35 0

3 00c 20 40 60

Percentage of Reinforcement

d

) I I I \ \

6.75 7.20 7.65 8.10 655 9.00

Net Cross-Section AreaSq. In.

Fig. 43. Comparison of Ultimate Load and Percentage of Reinforcementfor Plates with Openings.

-74-

70,000

0sowl

65,000( $ 10

0’ ~7

012

[4 016

60,000oe

@,20 022

55,000He

3

.7

.14

50,00 0

.19

45@0 0 0 CIRCUUR OPENING

o SQUARE OPENING, ROUNDED CORNERS

c SQUARE OPENING

40,000- 1 I I0 20 40 60 I

Percentage of Reinforcement

II

,.

0

1 I I I I I6.7S 7.20 7.6s 8.10 8B5 9.00

Net Cross-Section Area - Sq. In.

Fig. 44. Comparison of Ultimate Stren@witi Percentage Of ReWorcementfor Plates with Openings.

-75-

70

I

(

65

60

65

50

45 12 46

Ratio of Half-Width of Opening to Notch Ri@US-@N

Fig. 45. Relation between the Ultimate Strength of Plates with Openingsand the Notch Acuity of the Openfng.

-76-.

I

3nn7ivd 04 1 1

avol 31vN111n oLL 1 i

II I

1 I1 J

I II

I 1i

I J

1I I

II

1

I! I

a I0 I~d*Z I I I 1, I-=’d -@l=WWn

w~al 3“v0’-avol 31vnl17nOA

g Q

E._L..-

g ~ 8 * Gin

“81-”NI S,0001 – NOlldUOS8V AW3N3 0

160C

14 Oc

1200

1000

800

600

400

-77-

@02’

0s ..18

d7 d’

#

&2 0’2

o’

,20

m’ . 7

.14

.19

I

I

,:

0 CIRCULAR OPENING ~ SQUARE OPENINGo SQUARE OPENING, ROUNDED CORNERS

1 I r 4

20 40 60 80 100Percentage of Reinforced

I

I

t. t6.75 7.20 7.65 8.10 8.55 9.00

Net Cross-Section Area -Sq. In.

Fig. 47’. Comparison of Energy Absorption to Failure and Percentage ofReinforcement for Plates with Openings.

z

Energy Absorption to Failure, 1000’s In-lbs.

0)o0

CIRCULAIl

+

SQUARE OPEN

%

)

/

-’4-/--1-/

I

I

.8–L.GIG K

I I

I I

aiiEu-

-79-

10

9

e

7

6

5

I

I

I

&--II (32 d’ I

01 I

0’805

017

21

10——— —_. -

4---I

ICIRCULAR OPENING

SQUARE OPENING –ROUNDED CORNEF/S

I 1.❑ SQUARE OPENINO

10 15 20 25!

Efficiency wit.h Respect to Energy Absorption to Failure - Per Cent

)

Fig. 49. Comparison of the Efficiencies with Respect to Ultimate Loadand Energy Absorption to Failure for Plates with Openings.

,

-80-

I 0(

10(

9!

9<

e:

8C

75

7C

--i+

■‘14

T

,?

~3m8

d

.7—

~s

-—— .

~22

o

❑

~18

do

:21

t

——— ___

I

CIRCULAR OPENING

SQUARE OPENING,ROUNDED CORNERS

= SQUARE OPENING

20 25

Efficiency with Respect to Energy Absorption to Failure - Per Cent

.

Fig. 50. Comparison of Efficiencies with Respect to Ultimate Strengthand Ensrgy Absorption to Failure for Plates with Openings.

II.0

I dL ,.V-id An ,Caz

*

-82-

.

. .

+*R

_.— -—.

9*

q.

_$3-

e

-84-

.

.

‘J.,.

\

*

e“.

-85-

Ztjk

0

-“

-841-

.87-

.

%..

./

/

./

—.

.

.-

.

-88-

:,5

0:

.

0t’

-89-

‘+R

—.—.—. — -

~4

.

.

.

$’

2/:/

,/’/

//

,., ,/’,, \,.2

,7.’,, .//’ )? ,%

g

—.

/’

,

-92-

.

.

sp~ . No. ~. 18.D ~ 1/411 D~~bl~~ p~t,e

Circular Opening.

SpeC. lio. 13. 1811x 181’ x 1//+11 Doubler Plate.

Square Opening.

.

Spec. No. 20. U? 3/4” x M 3/1+”x 1/2” Insert plate

bqusrs Opening

Fig. 74. Photograph of Rim of Openingwhichducded Iaterdy duringLmading. PlateswithDifferentTypesof ReinforcementandOpening.

-9J.b -600

550

450

A 400

?la

300

250

2000 03 Lo M

Buckling fn Inches

2.0 2.5

Fig. 75. Comparison of Load and the Maximum Lateral Deflection of theBuckled Edge of Opening in Plates with Open@s.

-95-

Spec. No. 1

●

✎ ✎

✍✍✍

:, i-.

,,.

—--*. -.,, @nw,h h

1!..“.@’ “. i..., ~$, .. . .,<:

Spec. No. 2

SPC. No. 23

Spec. No. j

Spec . till. 5s?ec. No. L

Fig. 76. Photographsof PlainPlatesand Phtes withOpeningsafterFracture

-96-

.

Spec.No. 6 Spec. No. 7

Spec. No. 8 Spec. No. y

bpec. No. 10 Spec. IJO. 11

Fig. 77. Photographs of Plates with Openings after fiactue

-97-

Spec.No. 1.2

Lpec. NO. 16

Spec. No. 13

.

Spec. No. 15

Spec.No. 17

Fig. 78. Photographs of Plates withOpenings afterFracture.

-98-

.

.

SpeC. Mo. 18 Spec. No. 19

Spec. . No. 20Spec. No. 21

bpec. No. 22

Fig. 79. Photogmphs of Plates with Openings after Fracture

-99-

600

500

400

200

100

0

1A

‘o va~ x

%

!

‘To

I

SPEC. NO.5 x SPEC. NO. 14 06+

70 16 + ●!

80 170VI

90” 18 v

10 ● I19 v —.....-...— .—

II A 20 ?ti

12 A 210

13 e 22 ●I I I

o 4 8 12 16 20

TOTAL WIDTH OF FRACTURE IN INCHES

.

‘

Fig. 80. Comparison of To~l Lo~d on plate and TotalLength of Fracture.

-lCO -

55

50

45

40

35

30

TL 0 0-35% CLEAVAGE

\ ● 35-100% CLEAVAGE -+--.

\, I\

\\

\\

\

\\

\‘o

● \0

●\

\ ●

.\

\\ ●

✼

✼

✼ ●

✼✼

,Afi --- ---—2tJu *UU 600 800 1000 1500

Ratio of Half-Width of Opening to Notch Radus - R.@N

Fig. 81. Relation between the Ultimate Strength and the Notch Acuityof the Opening for Illinois Wide Plate Tests. Steel E asRolled.

- 101-

55

. 50

45

40

35

30

‘\ \\ \ \ \

o \\

o \\

\ ● \\

\\

● 1 ●\ !-‘8,!

\\ 8

\ ●

✼

✼●

✼●

✼✼

✼

✼✼

✼✼

0 30-35 % CLEAVAGE ___

● 35–100 % CLEAVAGE

200 400 600 800 1000 1500

Ratio of IIalf-Widti of Opening to Notch Radius - %~N

Fig. 82. Relation behveen the Ultimate Strength and the Notch Acuit yof the Opening for Illinois Wide Plate Tests. Steel D asRolled.

55

50

45

40

35

30:

\\

\

o 0-35 % CLEAVAGE

0 35-1009. CLEAVAGE

‘\ +.\ \\ 8 \

\

\\

●\\

\

\

I

I I

o 400 600 @

}o

T\‘oo\

T\ a\*\ \

) 1000 15

Ratio of Half-Width of Opening to Notch Radius - R@tN

o

Fig. 83. Relation between the Ultimate Strength and the Notch Acuityof the Opening for Illinois Wide Plate Tests. Steel DNormalized.

65 -

k

●

600

●

o

55\

50

- 103 -

I I I\

“\\

O SHEAR FRACTURE

● CLEAVAGE FRACTURE

● \

\

o \ .

●

● o‘o

\\ : \

\,\

\\ i

\\.

@

\●. 1’ \

45\* ;Io \\

*

\●

\\ 8

1 ‘440 ~

@

\\\: e

\

353 ~ ‘\10 20 40 60 100 200 4 )

Ratio of Half-Width of Opening to Notch Radius - @tN

Fig. 84. Relation between the Ultimate Strength and the Notch Acuity ofthe Opening for Wide Plate Tests by Thomas and Windenburg.Steel E as Rolled.

APPENDIXA

EEVIEWcl REF’EifJ?ENCRSIN TEH!MICALLITBBATDREclNcmmGs IN HA~. ,:. .

The t?zlldy’sfi Of the 6tXWSS distribution .8d ths StIW9S COIIOSI)-

tratlon .ti the region” of an opening in a pl.ati is a ch engineering

problemsncountersdin the dssigoof YMny typesof struct~s. This

problemhas been the subjectof many papra In th6”tdbnioal I.lt.ereture,!.

and this seetionof the reportwill verybrie~ describethe ecopeof the

more importantpaprs. Whilethisreviewof the ticbiicalliteraturehas

been rqt,herextensive,it dtis not presumeto hsvefoutidall the avail-

able Informationof significance.A bibliographyof tie‘rs’fersnces18

givenat the end of thisappbndiit.

1. MathematicalAnabaes of StressesIn Plateswith knf~.

The analysisof the elasticstressssIn plateswith openingsby

the methodsof the theoryof elasticityhas beenalinostentirelylimited

to the solutionsfor platesof infinitadimensionsend uniformthicknese

acteduponby uniformdlstributioneof appliedstressat the boundariesof

the plats. Theselimlthtiooe’have beenImposedby the mathematicalcom-

plexityof the procedurerequiredto developsuitableetressfunctions

for the problem.

The simpleetcase of an opening

of mathematicalcomplexityla thatof the

in a platefrom the atandpcint

Inflnitiplateof uniform

thicknesswith a centralolrcularopening,the platebeing subjectedto

uniformuniexialtension. Kirsch(3) publishedan approximatesolution

for this problemin 1898. The complete~themeticalsolutionwas given

-2a-

laterby F6ppl (L),!desneger(5),d Wyss (6). These aoalyaes lead to

the well-knownatreee-concentration factor of three for the tension etreee,.:!,

at the edge of t.tm circular ope~ at the pointe on the centerline trena-

varee to the direction of the appliedbtreee. The faotor of three ie,.

;elati& “*o‘tb uniformtenatiestress,whichis E@ied ta the,plata

alonga eectionremotefrom the opening.,..

Inglie(7),!?o~”(8),&relli and Murray(9, 10),,exte@@these,.,

eolutioneto the“caseof en elliptical npaning located ,$11an infinite

piate of uniform thickness. For a uuifo~, ?~ied, vn@xlal tensile. ‘.,

etrem on the plate, they found that the rt,reee-concen,tratlon feotmr at,,,. ..,.

the’ “eke of the op&ing lyingon the trensvareecenterlinevariedfrom

one to three,if the MSjor axis of the ellipticalopeningwere parallel

to the appliedstressend from threeto infinity,if the minorSXISwere

parallelto tb”“&ppli’edstress.

Many of theeesolutions,,.,,

or combinationsof pure ehaarand

ariee of the plate”

. ...,.

also treatthe caseswherepure sheer

directstreseare,appliedto the @u@-

,., ,,.,.!..

The solutionsfor the case of a equsre~ning in en ir@nl$e,.

plateof dform thicknessare much more dii’ficult.No ,nexactnsolutions,.

were foundto havebeenmade,prlncip@.lybecausaof the &f ficu3ty.of

expressingthe shapeof a squareopeningmat@atically. Ey approdmting

a equere’openingby an ovaloidwith a varysmallcornerradius,Greenspan,..

(n) founi the pointsof maximumst~ss concentrationin q idinite plate

underuniformlyapplieduni-exlal,streas.If,the two sidesof the sqwre

openingwere Perallelto the appliedetress,the fourpointeOf m%xi.mom

-3a-

stressconcentrationfellvary c106E~ the cornersof the opad.ngand on

the etdeecd’the openingparallel to the applied etraas. If w dia-

gonalof the equareopeningwere parallelto the appliedetrees,the two

pointsof maximumatreea

the equareopeninglying

The problemof

a circularepeningIn en

concentrationwere locatedat tha cornereof ‘

on the trenevereecentmline.

the triaxielstreaeconcentrationon tlw edge of

f.nfiniteplateof uniformthicknesswas fnwstiga-

ted by Sternbargand Sedowaky(32),who foundthattriaxlaletressesneed

to be consideredonlywhen the ratioof the diameterof the circular

openingto the thicknessof the plateia leas than 30.

A verycomprehensivecoverageof the

was publishedby Neuber (13).

The effect of strains in the plastic

verioie theoratioalanalyeee

rangeof the materialwas

investigatedby Stowel (1.4).He foundthe atreesend strainconcentration

factorsto be a functionof the aec.antmodulusof the material.

The one eolutionfor a plati”of finitewidthend uniformthick-

ness is thet by Howland(15)for e centrally-locatidcircularopeningand

a uniformuni-exialstreseappliedin the Infinitedirectionof the plate.

If r is the radiusof the openingend b the hal.f-idthof the plate,the

etress-concentrationfactorat the two pnlnteof the op&ing on the trans-

versecenterlinevariesfrom 3 to k.32 es the r“atiorib changesfrom zero

(plateof infinitewidth)to 0.5.

plateon the transvereecenterline

from 0.1 to 0.5.

The stressat the outeredgeaof the

variesfrom”0.99 to 0.73ae r/b changes

.-. La-

in all theseanalyses,tbe authorefoondzonesof compressive

strae@adjacentto ti edgasof the openingwhichlay on each aideof the,!::<j. .,::..,,,

tradzk~e een?%rtie,when the strass””~6”ap@ied in“t~ longltwlinal

&actIon of k“ pl+.e, ad +ok a stress lo these reglone almet ez...

@eat as In the regione of +,emelleetreea. Ho ~ntlon wae foundof the

Posafbilltyof lateral-- of the platein A8 regloneof oomprasa-

iva atree~lf thi tihi~ai of the plata bicemi itifioiently pall.

The affect of s eiiaple type of reinforc&nataroundn c~cular,,

opanirigin .9plateof inftite extentand of uniformthlckneeaexcept. . . . .... . . .

for the reinforcementwas in&etigatedby Gurney(16),Beskln”(17),

Reissnerand Morduchov(18). The appliedetreseon the platecouldbe

uniformuniaxialor bizxialatreesor uniformehaer. Gurneyanalyzedr ,.;.

the caae of a ring aroundtb opening,whileBasklnaolvadtha caaeeof

Yelkorcemen’tby a ring,by a him end by the ring and the rim eombtned.,-, .,:,.‘“”Both”authors“suppliedteblesof valuesto & usedfor strasacomputation.

,,.,,,, ....,The mathematicalanalysesof the effectof reinforcementopon

.,, ,., ..

the”e~stic stressesin thk region;f the‘openi~“~int to ievwraiim-...... .......,

portit fiote~,, .:. ,.

l.. An incree6eb the cmountok N“inforcementde~aaees

the circumferentialstress,but thisdecreazeis not,,’

proportionalto the increaseIn the amountof reinforcement.,.

2. An inczeeaein the amountof reinfOroerEnt incraazesthe

shearetressat the outerbow of the reinforce-,.

mant. Thus,it ie not poeslblefor relnforoezmntto

velopin the platewith en openingthe etrengthof a

plat%.

de-”

eolld

-5a-

3. ‘Z* qmqe+octlnn am+a ef tba reinfo=e-nt on * trane-,.,

wares man&Jine la more effectlm upon the values of the

+resaea then the beding eti.ffnasfi .M ~ reinforcement

.. at ths asm cross 8eetion*

2. er men etab i’ ‘tel~ ru&net.ion afS~eeln Ple s h@ete wit mlnm .

Some ,expeniment.el Investigation of the strasees in plebe uith

open.inge has keen c+rrl?d. out. Most of tble work was concerned with the

verification of fnformaM,on obtained from the theoreticalsolutione.

Kirsch (3) end Prauas(19) I,nyaetigetadplatesof f inlta width

end unlfmm tnlcknesawith a eantrally-locatidcircularopening. For

uniformlyapplieduni-axialBtress,the~foundgood oorraletlonbatwesn

the veluesderivedfrom .,e,xperimentepd thosefrom theory. Preueadeter-

minedthe effectof,vary+g the ratioof the dlemeterof the openingto

the widthof the plateend foundvaluesof the stresseswhichwere In good

agreementwith thosecc@putedtheorstlc.allyat a laterdate by Howland,..

(15). Sitilarres~ts were publishedby Hill@ Serker(20)for plates

of variousaluminumalloys.. ,..

Analysisof the stressesaroundopeningsby the photo-elastic

methodwas madeby Durelliand ldurray(9, 10),and Frocht(21)for the

cesesof tha circuler~d the ellipticalopanlngean~.by Coker,apdKimball

(22)and Heymns (23)“for,the case of the‘sqmre openingwith rounded

corners,the two eidesof the equareopeningbeingparallelto.the applled

tenaio~ Unl-~al stresswas used ib theseinvestigations. .”

The stressesin stlffenadsteelcompressionmemberstier unl-

axial t?tresswere determinedfor squarsand”rectangularopanfngsbv.Stang!,

and Greenspan(a, 25). Similarexperimentson etiffenedelumln~loy

pnels in tensionand in kandingwith circularand rectangularopenings

v.waw mk$a by Farb (26)and.Kuhn,Duherg,~“ .Oiakin(27).

...... .::?..’,...GOOU com.elation~th thaordtloelanalyees...waefoundin exprl-

: mental “dnwt3tigations of i%~et,~~ circti. openings in eJ.um-‘/

lnum-alloy specimens w Kroll ad McFhsnnon (28), la~, Woolley, and Kroll

(29), ‘@ Cr$fflW .(30),j; .C~&ff&th showed .$&it the data f~ fl.ati platee

ceuldbe qplied to curb6& pht,as if tbe ratio ..& t@ radliae of curvetura

of the latterto tb, rediwimf the openingwaa’.nutleas tkSO“~i The

other imastigatorsreportd the loner limit of:%kiis. ratio &a’am,. while

~‘T.~‘limoehenko(31)givesa.valueof fIve.,,,

., Becauseof the-.difflcultyof measuringaceiariitklgthh etraine

in the ~ry smallregiobeof &gh straincOn&en*i.ationy!the taxiti

., maeurd etrainain the e~erlmantd:xe@rts ~wele“often:.no+,60”largess

..thosepredictedbyt,he:biy.~.Moreoberj the plaeticI’1oTthatoocurredin

...... theseregionsat low &oadsimdestitidactb~ ebservaticim’clifftctllt.

One reference-waB f ovnd on the effectiveneaaOf am-welded re-

lMorc@ment;an investigationof the”strengthdevelopedby different;types

of reinforcement around circular end equare O@lnRB & the David ‘1’ti~lor

~.,.Model-Swin (32). ,,;..

. .. . . .

Bibliograr@.3. ‘“.,

1. Wileok,W. h!.,Hechtmn, R. A., Bruckner,W. H., CleavageFractureof~“,.Shi@.Plataeae Influenced%y”Size Effdot;WeldingJourki.”,’1948,Vol.

27, p. 200-e.,..-, ,,;,-..,:,. ..

2. Thomas~ “H.R., Widenburg,D. F., A Study of SlottedTeneileSpacimenefor E~ting the Toughneee‘ofStructuralSteel,Wsldihg,Joti.,1948, Vol.27, p. 209-e.

“”3. Kl&,chg~., Die Theoriedee Elastizitaetund die Seduerfnieseder.j.-Fes%$gkeitcZieit.V.D.X.~.1898, Vol.11, p.:797. ~~

,.:,,,.,,!- ., .,: -::’. ..”.. . .. . ... . . ..

,. .,

..,, .,.

-7a-

5.t

.:.6.

7.

8.

9.

10.

,.

11.

1.2.

13.

15.

16,

. .4 -..Foeppl, A., Vorlesungan uabartechnischenM&anlkI 1%’7,~L 5,p. 352. : . .. ,’~,.

Mamager, A.; Dete-tlon ~kri~e’ de; effki.aintarieure damles eolides, Uem. den Sciences P&aiquae, F.x. g 192%.cbP. %. ‘

.

WySs, T., Die Kraft.&lder in feet& elaatiechan K08~rn, 1%6,Springer, Berlin, p. 191.

.-

Inglia, C., StrasE In Platedue to the Presenceof “~=cksand S&~Corners,Proc. Inst. Nav. Amh., 1913.

wolf, R., Baitreege su ebanan Elastizitaetetheorle, ZaIt. Techn.Phys. , 1921, 1922.

Duralll,A.J., m, W. M., StraseDiatributlon~ound e Circ&arDiacontlnultyIn any Two-DimensionalSystemof CombinedStrees,EasternPhotoel. Conference,pSOC.~, 19~, P. 21.

Durelli,A.J., Murray,W.L!.,Stre.seDistribution.ar&nd an Elllpt~calDiscontinuityIn any Two-DimensionalUniformand AxialSystemofCombinedStress,1%.S.A., 19/+3,VO1.1, No. 10

.,. .

Greenspen,M.”,Effectof .#’Snail..Hole on tbe StressesIn a Unifcn’mlyLoadedPlate,Quart.of Appl.;Ma%h.,.Apr..1944,.Vol.II, ~..GZ.

Sternbarg,E., Sadowal&,M.~~.T&ee-Diwneional Solution for #mStress Concentration Arcund A ClrcuSar kale In a’ Plate .of ArbitraryThickness, MILE, Jum 1948. .,’

Neuber,H.,.Kerb+annungalehr%,Grundla@n fuargenauesw~gsrec~~~Berling,J..Springer,1937. (Translation!74iD.W. ‘faYlorMel Basin,U. S. Navy).

Stowell.,E.F.,“Stressand StrainConcentrationat .aCircularHole Inan.InfinitePlate,NACA,April1950,Tech.Note.2073.... .Howland,R.C.J., Streesesin the Neightmhcodof a CircularHole ina Strip underTeneion,Hny.Sot..London~Phil.Trans.,1930,VO1.229,p. 49.

Gurney,C., An Analysieof the Stresses’~ a F1.etPlatewithReinforcedCIrcd.arHole underEdgeForcee,Mt. Res:.Memo..,1938> NO. 1834.

;. .,-17. Beskin,L., Strengtheningof CircularWles In Platasunder Edge Loade,

Journ. Appl.Mech., 1944,P. A-L$O...’

,., . . ....

-8a-

18. Reimner, H., Morduohov,Sheevs,NACA,Apr. 1949,

M., RelofkedMrcul.ar CutouteIn PlaneTech Note )852-

19. Prbuee, E., Versuohe usherdie S.:,., ,,

Zug.eteebe. , Zeit. V.D.X.,19X2,~.~y%k? h ‘1*~~., .’.,

20. Hill,,H.N. Sarker,R. S.;”Effeoto?.~ CArOulsrIbleem ~enefieStrengthend Elongationof SheetSpeclmene,NACA,Oct. 1949;TsolbNOtC1,974. .,,..:..

.-.-:

21. Fmcht, Au., Photoelsstlcitp,J. willey,N.Y.,1941-1948;‘-VOI.1-11.

22. Coker,E.G.’~Klmti,”AL, The Sf@ct of Noles, Cx&&# +,,j~erDiscontj.nultiee10 Shlp!sPlating,”Tr... Indt.Navel.AI’Oh;-“Y920s

23.

2#i.

25.

26.

27.......

28.

29.

30.

31.

32.

?fo1.LXII,p. ~’?. - , ;;,,,..,,,‘..

Heymane,P., La deterudnationpar la pitotoelast,lcimetrla din-”‘a~n-eione, AcademieI@yelq.,.deBelglque. Classe,de8Sciences,.&E-ln-6-0,& eerie.,%1.”VI, PS6C.,10;~ .,. .

.,,. -

Steng,A.H., Greentipa.n,M., PerSotitedCowr Platesfor SteelColumne,Surmaryof comprerjeivePropertiefi, Journ. of Hes. N.B.S., VO1.40,No. 5, p. 344-359. ,, ~,....

Steng, H., Greenepan, bi., Petiforated Cover Platea for Steel Columns,Journ.of HSS. N,at.%ureauof Standards,1942-1944,VO1.28* P. 669and 687; Vol.29, p. 279; Vol..:30,p. 177 and 411.

Farb,D., Experimnt.elIn~stigationof the StressDidrlbutionaroundReinforcedCircularCut@@a in Skin-Strln@rPanelsuodertitiLeads, NACA,Merch19.47,”Tech.Not@ 12.41.

Kuhn,P., D@erg, Y.E.,Diekin,S. H., StressesarourxlSeotengulerCutoutsIn Skin-StringerPanelsunderAx@ “~dp, NACA,Oc& 1943,WartimeReport,AHS 3T02.

.,

Kroll,w~., AlcPherson,A. E., Compresal~.,Testof Curvedp-l ~thCirc.~ar“’Ho,LeReinforcedwith Clro@kr Do~ler Pla’tes,J~... :Of’‘“the Aerons~icelSciences,June 1949;Wol.’’16;No. 6, p. 354. ‘“

Leqr,S.,.Woolley,R.M., Itrol.1,W.D*~,Iust#b~ity of Simp~”S~~edSquarePlaiewith ReinforcedCiroulai’Holb”IiIEdge Compreeelon,Journ.of Research,N.B.S., Vol.39, No. 6, p. S71.

Griffith,G.E.,’Expal&ntal InvestigstloRof the Effeotaof PlasticFlow IIIa ‘fenkionPenelwith a CircularHole,NACA,’Sept.1948, Teoh.NOtA1705.

,!Timoshenko, S., Strength of Materlkls’; “D.’Vsn Nostred Co:; S .Y.,2nd Ed., 1%1$ Part 11, p. 315.

U. S. Exp. ModelBaein,NavyY.erd,Waehlngton,D.C., The Effectofopeningson the UltimeteTeneileStrengthof Flat Plates,Rpt. No. 446.