SP 6-6 (1972): Handbook for Structural Engineers -Part- 6 ...

1 Disclosure to Promote the Right To InformationWhereas the Parliament of India has set out to provide a practical regime of right to information for citizens to secure access to information under the control of public authorities, in order to promote transparency and accountability in the working of every public authority, and whereas the attached publication of the Bureau of Indian Standards is of particular interest to the public, particularly disadvantaged communities and those engaged in the pursuit of education and knowledge, the attached public safety standard is made available to promote the timely dissemination of this information in an accurate manner to the public.

2 ! $ ' + - Satyanarayan Gangaram Pitroda Invent a New India Using Knowledge 0 1 ' 5 Jawaharlal Nehru Step Out From the Old to the New 1 + , 1 + Mazdoor Kisan Shakti Sangathan The Right to Information, The Right to Live ! > 0 B Bhart hari N ti atakam Knowledge is such a treasure which cannot be stolen Invent a New India Using Knowledge SP 6-6 (1972): Handbook for Structural Engineers -Part- 6 Application of Plastic Theory In Design of Steel Structures[CED 7: Structural Engineering and Structural sections]lSIHANDBOOKFORSTRUCTURALENGINEE RSNo.

3 6 lSIHANDBOOKFORSTRUCTURALENGINEERS6. APPLICATION OFPLASTICTHEORY INDESIGNOFSTEELSTRUCTURES~Ic:i'I!:JI~ ,BAHADURSHAHZA'ARMARGNEWDELHI1100U1\.,,I INDIANSTANDARDSINSTITUTION. Edition I1972.( )UDC624'014'2:624 ~SP: 6(6)-1971 Copyright1973 INDIANSTANDARDSINSTITUTIONT hispublicationisprotectedundertheIndianC opyriglJtAct(XIVof1957)andreproductionin wholeor inpartbyanymeansexceptwithwrittenpermiss ionofthepublishershallbedeemedtobeaninfr ingement Deihlf"" CO .FLEXUREOFB~AMSSECTION DPLASTICANALYSIS~ ! ~ 7777788112512513617818718718819119519820 3 SEC-216 SECTIONG SIMPLIFIED (SINGLESTOREV) ,5 MBDC 7 APPEMDIXEINDIANSTANDARDSRELATINGTOSTRUCT URALENGINEERING218 SECTIONFDESIGNEXAMPLES24.

4 ,INTRODUCTION.;,. :6(6)-197 SP:6(6)-197 JFOREWORDThisHandbook,whichhas beenprocessedbytheStructuralEngineeringS ectionalCommittee,5 MBDe7,thecompositionofwhichisgiveninAppe ndixD,hadbeenapprovedforpublicationbythe StructuralandMetalsDivisionCouncil andtheCivilEngineeringDivisionCouncil oflSI"Steel,whichisaveryimportantbasicra wmaterialsforindus-tdatization,had beenreceivingattentionfromthePlanningCom mis-l'ioneven fromtheveryearlystagesofthecountry'sFirs tFiveYearPlanperiod,ThePlanningCommissio n notonlyenvisagedanincreaseinproductionca pacityillthecountry,butalsoconsideredthe questionof evengroaterimportance,namely, ,'steel.

5 ThePlanningCommission,therefore, ~tionsandcodes ofpracticeinthefield ofsteelproductionand ,'andthedeliberationsatnumeroussittingso fcommittees,panelsandstudygroupsresulted intheformulationof anumberofIndianStandardsinthefieldofstee lproduction,design and use, alistof whichis, design ofsteelstructuresisintendedtopresentthei mportantprin-ciples andassumptionsinvolvedintheplasticmethod ofstructuralanalysis, of asteelstructure,thelimitsthatarefunction (inpart) ofthesepropertiesis used inSectionAto show howthemaximumstrengthof somesimplestructuresmay 'Whyplasticdesign',ItisshownIthatItrelli sanmad,equatedesig,ncriterion for a largenumberof7 SP:6(6) (which basesthedesignofstructureson.)

6 Themaximumstrength)hasalso and ~ fewexamplesrelatingtomultistoreyframes,i tisproposedtodealwiththesubjectindetaili na ,modificationsanddesigndetailshavebeende scribedundertheheading'SecondaryDesignCo nsideration'.Properattentionshouldbegive ntotheeffect ofshearforce,axialforce, localandlateralbuckling, ,thebeams,columnsandconnectionsshould bedesignedtomeettherequirementsofplastic hingeformation.'. offormulas, a list ofselectedreference') 'sidewalksuperintendent', a , ,itwillmeaneconomy,becauseplasticdesignr equires less ,itwouldmeanmoreefficientoperationsbecau sed~ steelindustry,Itwouldmeanmoree8iCltmtusc ,to anation,itwillmeanbetter111 Iof : (standardquality)Vourthrevis"",)IS:800-1 962 Code ofpracticefor use ofstructuralsteelingeneralbuildingconstr uction(revised)IS:875-1964 Code ofpractice'forstructuralsafetyofbuilding S:Loadingstandards(revised) (fusionw~ding(quality)(firstrevisio1l),I S:400().

7 1967 Code ofpracticeforassemblyofstru,cturaljoiDti usinghightensilefrictiongripfasteners8 SP:6(6)-It':JInthepreparationofthishandb ook, ,ProfessorofStructuralEngineering,Lehigh University,Bethlehem, ,Inc,Iron,andSteelIndustryConsultants,Ne wYork,bytheTechnicalCo-operationMic;.~ touscit,theywill be able willbereceivedwithappreciation"andgratit ude. SP:6(6)-I9nSYMBOLSS ymbolsusedinthishandbookshallhavethemean ingassignedto them asindicatedbelow:AA,A"-AwbcIIEE"E, ,JKkKL,Li; ofWFshapez=Area ofsplit-tee==Areaof webbetweenflanges==Flangewidth==Distance fromneutralaxistotheextremefibre==Dept'h ofsection==Young'smodulusofelasticity=St rain-hardeningmodulus=~O'd--"==Tangentmo dulus=Eccentricity=Loadfactorofsafety;:; :Shapefactor=~~=~.

8 ,.=Fixityfactorforuseinevaluatingandrest raintcoefficient=Modulusofelasticityinsh ear=Modulusofelasticityinshearatonsetofs train-hardeningc::Hingerotationrequireda ta plastichinge=Portionof hingerotationthatoccursincritical(buckli ng)seg-mentofbeam==Momentofinertia==Mome ntofinertiaofelasticpartofcross-section= =Momentofinertiaofplasticpartofcross-sec tion==Numberofremainingredundanciesinast ructurethatisredundantatultimateload==Eu lerlengthfactor=Distancefromflange'facet oend offillet==ERective (pin end) lengthofcolumn-Spanlength; SP:-6(6)-1972m-Numberofplastichingesdeve lopedin astructurethat" ;ausefulmaximummoment;hingemomentMI'=Pla sticmomentMp=Plasticmomentcapacityof abeamsectionM~=Plastichingemomentmodifie d toincludetheeffectofaxialcompressionM.

9 =Plastichingemomentmodified toincludeeffectofshear'forceM,=Maximummo mentof asimply-supportedbeamM,=Momentatwhichyie ldpointisreachedinflexureM,e= ~= load used asthefmaximumcolumnload'"p,"==Eulerbuckl ingloadPro= ,= ,=Axialload'correspondingto yieldstresslevel;P=Aa,R-Rotationcapacity ,=RadiusofgyrationS=Sectionmodulus,I]cS_ =Sectionmodulusofclasticpartofcross-sect ionT=ForceII= '.FWebthicknessV=ShearforceVc==Shearcarr yingcapacityof asectiontI,v,III==Displacementsinx,y,and , SP:6(6)-19?:JayyZ-, ,Z,,6. 8 Wur-=Externalworkduetovirtualdisplacemen tWINT=Internalworkduetovirtualdisplaceme ntUJ-Distributedloadperunitoflengthwtl= ~=Longitudinalcoordinatex=Distancetoposi tionofplastichingeunderdistributedload= ~I!

10 TS,-Plasticmodulusofelasticportion=Plast icmodulusofplasticportion=Lateralco-ordi nate=Equivalentlengthofconnection=Drflec tion=Strain=Strainatstrain-hardening=Str aincorrespondingto_firstattainmentofyiel dstresslevel==Mensurcdanglechange; 'sratio=Radiusofcurvature-Normalstressa" =Loweryieldpointa,=Proportionlimita,==Re sidualstressOttu=Ultimatetensilostrength ofmaterial(I.,==Upperyieldpointa.,=Worki ngstresscr,=YieldstresslevelTc=:Shearstr essatRotationPerunitlength,oraverageunit rotation;curvature==Curvaturecorrespondi ngto firstyieldinflexure13 and be des-cribedtogetherwiththedesignprocedure sthat'have frames ofstructuralsteeltocontinuousbeams, ,butforthetimebeingthescope ofapplicationislimitedto" ,'-auniquepropertythatnootherstructuralm aterialexhibitsin' abletoabsorblargedeformationsbeyondtheel asticlimitwith-outthedanger"offracture.)