abaqus帮助文档之地震相应计算分析

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1、2.1.15 SeismicanalysisofaconcretegravitydamProducts: Abaqus/Standard  Abaqus/ExplicitInthisexampleweconsiderananalysisoftheKoynadam,whichwassubjectedtoanearthquakeofmagnitude6.5ontheRichterscaleonDecember11,1967.Theexampleillustratesatypicalapplicationoftheconcretedamagedplasticitymaterialmodel

2、fortheassessmentofthestructuralstabilityanddamageofconcretestructuressubjectedtoarbitraryloading.Thisproblemischosenbecauseithasbeenextensivelyanalyzedbyanumberofinvestigators,includingChopraandChakrabarti (1973),BhattacharjeeandLéger (1993),GhribandTinawi (1995),Cerveraetal. (1996),andLeeandFe

3、nves (1998).ProblemdescriptionThegeometryofatypicalnon-overflowmonolithoftheKoynadamisillustratedin Figure2.1.15–1.Themonolithis103 mhighand71 mwideatitsbase.Theupstreamwallofthemonolithisassumedtobestraightandvertical,whichisslightlydifferentfromtherealconfiguration.Thedepthofthereservoiratthe

4、timeoftheearthquakeis  =91.75 m.Followingtheworkofotherinvestigators,weconsideratwo-dimensionalanalysisofthenon-overflowmonolithassumingplanestressconditions.Thefiniteelementmeshusedfortheanalysisisshownin Figure2.1.15–2.Itconsistsof760first-order,reduced-integration,planestresselements(CPS4R).

5、Nodaldefinitionsarereferredtoaglobalrectangularcoordinatesystemcenteredatthelowerleftcornerofthedam,withthevertical y-axispointingintheupwarddirectionandthehorizontal x-axispointinginthedownstreamdirection.ThetransverseandverticalcomponentsofthegroundaccelerationsrecordedduringtheKoynaearthquak

6、eareshownin Figure2.1.15–3 (unitsof g =9.81 m sec–2).Priortotheearthquakeexcitation,thedamissubjectedtogravityloadingduetoitsself-weightandtothehydrostaticpressureofthereservoirontheupstreamwall.Forthepurposeofthisexampleweneglectthedam–foundationinteractionsbyassumingthatthefoundationisrigid.T

7、hedam–reservoirdynamicinteractionsresultingfromthetransversecomponentofgroundmotioncanbemodeledinasimpleformusingtheWestergaardaddedmasstechnique.AccordingtoWestergaard(1933),thehydrodynamicpressuresthatthewaterexertsonthedamdurin