1Example43TitleTransientresponsetoastepexcitationDescriptionAspring-mass-dampingsystem,initiallyatrest,issubjectedtoastepforce.Performatimehistoryanalysisandcomparethemaximumdisplacementsofthestructurebetweenthecasesofdampingandundamping.VerificationExample2StructuralgeometryandanalysismodelExample433ModelAnalysisType2-DtimehistoryanalysisUnitSystemin,lbfDimensionLengthL=100.0inMassM=0.5lbf⋅sec2/in(Yaxis)Analysistimet=0.25secTimestep∆t=0.0025secDampingratioξ=0.0(0%)ξ=0.5(50%)ElementTrussElementMaterialModulusofelasticityE=20000psiSectionPropertyAreaA=1.0in2BoundaryConditionNode1;ConstrainallDOFs.Node2;ConstrainDxandRyAnalysisCaseStepforceactsintheYdirection.Thetimestepforcedataareasfollows;Time(sec)Force(lbf)0.00252000.2050200VerificationExample4ResultsDisplacementsatthenodes2(Dampingratiois0.0)Inthecaseofdampingratiois0.5Example435ComparisonofResultsUnit:inResultTheoreticalMIDAS/GenMaximumdisplacementDampingratio=0.02.0002.000Dampingratio=0.01.6541.672Displacement(t=0.2sec)Dampingratio=0.51.15311.1543ReferencesThomson,W.T.,“VibrationTheoryandApplications”,Prentice-Hall,Inc.,EnglewoodCliffs,N.Y.,2ndPrinting,1965,p.102,Article4.3..VerificationExample6Stepforcedata
