1AnalysisManualInelasticTimeHistoryAnalysis21.BoundaryConditions1.1GeneralLinkElementkrykrzjointikrxkdxkdykdzxzylocalcoordinateaxiscyiLcyjLLcziLczjLjointjFig1.1CompositionofGeneralLinkElementTheGeneralLinkelementisusedtomodeldampers,baseisolators,compression-onlyelement,tension-onlyelement,plastichinges,soilsprings,etc.The6springsindividuallyrepresent1axialdeformationspring,2sheardeformationsprings,1torsionaldeformationspringand2bendingdeformationspringsasperFigure1.1.Amongthe6springs,onlyselectivespringsmaybepartiallyused,andlinearandnonlinearpropertiescanbeassigned.Thegenerallinkcanbethususedaslinearandnonlinearelements.TheGeneralLinkelementcanbelargelyclassifiedintoElementtypeandForcetypedependingonthemethodofapplyingittoanalysis.TheElementtypegenerallinkelementdirectlyreflectsthenonlinearbehavioroftheelementbyrenewingtheelementstiffnessmatrix.TheForcetypeontheotherhand,doesnotrenewthestiffnessmatrix,butratherreflectsthenonlinearityindirectlybyconvertingthememberforcescalculatedbasedonthenonlinearpropertiesintoexternalforces.3First,theElementtypegenerallinkelementprovidesthreetypes,Spring,DashpotandSpringandDashpot.TheSpringretainslinearelasticstiffnessforeachof6components,andtheDashpotretainslinearviscousdampingforeachof6components.TheSpringandDashpotisatype,whichcombinesSpringandDashpot.Allofthethreetypesareanalyzedaslinearelements.However,theSpringtypegenerallinkelementcanbeassignedinelastichingepropertiesandusedasanonlinearelement.Thiscanbemainlyusedtomodelplastichinges,whichexistinpartsinastructureornonlinearityofsoils.However,thiscanbeusedasanonlinearelementonlyintheprocessofnonlineartimehistoryanalysisbydirectintegration.Also,viscousdampingisreflectedinlinearandnonlineartimehistoryanalysesonlyif“GroupDamping”isselectedfordampingforthestructure.TheForcetypegenerallinkelementcanbeusedfordamperssuchasViscoelasticDamperandHystereticSystem,seismicisolatorssuchasLeadRubberBearingIsolatorandFrictionPendulumSystemIsolator,Gap(compression-onlyelement)andHook(t...
