opensees中刚性隔板的模拟方法及其影响

《opensees中刚性隔板的模拟方法及其影响》由会员上传分享，免费在线阅读，更多相关内容在行业资料-天天文库。

1、ModelingDiaphragmsin2DModelswithLinearandNonlinearElementsVesnaTerzicUCBerkeleyOctober2011Introductiontotheproblem(1)•Floordiaphragmneedtobeaxiallyrigidtoassureproperdistributionofseismicforcestoalllateralforceresistingelements(columnsandwalls)•Common

2、modelingapproachforframestructuresistorepresentthestructuralcomponents(beamsandcolumns)bylineelementslocatedattheoriginalmembercenterlinesandhavingcross-sectionalpropertiesequaltothoseofcomponents•Commonwaytomodeltheeffectofarigiddiaphragmatafloorleve

3、lisbyimposingrigidconstraintsonallnodesofthatfloorlevelandthusenforcingthesamelateraldisplacementsofallnodesatthefloorlevel•Theseconstrainsenforceconditionofzeroaxialstrainonelements(i.e.,elementcenterline)thatarepartofthatfloorlevelIntroductiontothep

4、roblem(2)•Forsectionswheretheneutralaxisdoesnotshiftasaconsequenceofbendinginthebeam,axialstrainsatelement’scenterlinesarezero,andthusrigidconstraintscanbeappliedtomodelarigiddiaphragm(e.g.steelsections,elasticmaterials)•Fornonlinear-beamcolumnelement

5、swithRCfibersectionwheretheneutralaxisshiftsduetobendinginthebeamaxialstrainsatelement’scenterlinesarenolongerzero.Thus,rigidconstraintsthatenforceconditionofzeroaxialstrainonelementswillchangetheresponseoftheframeCasestudy•Theeffectofrigidconstraints

6、onaforce-basedbeam-columnelementwillbedemonstratedonaportalframeconsideringthreedifferenttypesofsections:–Elasticsteelsection–Nonlinearsteelsection–Nonlinearconcretesection•Force-basedbeam-columnelementischosenforthiscasestudyasitisthemostwidelyusedfo

7、rmodelingframeelements.However,allofconclusionsderivedfromthisstudyholdfordisplacement-basedbeam-columnelement.Example:portalframeTwotypesofanalysis:•Pushover(uptodisplacementof5in.)RCsections•TimehistoryanalysisBeamP(180)P(180)ColumnH3424”16”(3)16”16

8、”144”(1)(2)Steelsections12Column:W14x257360”Beam:W24x68Materials•Elasticsteelsection:Elasticmaterial•Nonlinearsteelsection:Steel02material•Nonlinearconcretesection:Concrete01forcoreandcoverandSteel02forreinforcementConcrete01Steel02ElasticStre