ws16-1研讨会汽车底盘模态频率分析培训nastran.pptx

WS16-1WORKSHOP16MODALFREQUENCYANALYSISOFACARCHASSISNAS122,Workshop16,August2005Copyright?2005MSC.SoftwareCorporation

MODALFREQUENCYANALYSISOFACARCHASSISProblemDescriptionForthisproblem,aunitforceisappliedtoanenginemountonthecar.ThemodelissubmittedtoMSC.Nastranforamodalfrequencyresponseanalysiswithamodaldampingof1%.Aftertheanalysisiscompleted,theuserwillbeaskedtoplotaXYPlotofdisplacementvs.frequencyatvariouslocationstoviewtheeffectoftheloadonthecaroverrangeoffrequencies.

MODALFREQUENCYANALYSISOFACARCHASSISSuggestedExerciseStepsImportthecargeometryfromaNastranInputFile.CreateasetofRBE2torepresenttheenginemount.SetupaTimeDependentLoadCase.Createafrequencydependentfield.AssignaunitforceloadtotheindependentnodeoftheRBE2createdfortheenginemount.SubmitthemodelforaNormalModesanalysis.AttachtheXDBresultfileaftertheanalysisiscompleted.Createagraphoffrequencyvs.displacementofthreelocationsonthecar.

CREATENEWDATABASECreateanewdatabasecalledcar.db.File/New.Entercar_frequency_responseasthefilename.ClickOK.ChooseDefaultTolerance.SelectMSC.NastranastheAnalysisCode.SelectStructuralastheAnalysisType.ClickOK. abcdefg

Step1.File/ImportImportthemodelfromaNastranInputFile.File/Import.SelectMSC.NastranInputastheSource.Selectcar.bdfandclickApply.ClickOKwhentheNastranInputFileImportSummaryappears.bcacd

Step2.Elements:Transform/Node/TranslateCreateanodethatwillbeusedastheindependentnodeoftheRBE2.Elements:Transform/Node/Translate.ChangetheStartingIDto10000.EnterDirectorVectorof

010.SelectNode5691.PleaseseetheFigurefortheLocationofNode5691.ClickApply.abcdghiNode5691e

Step2.Elements:Create/MPC/RBE2CreateasetofRBE2torepresenttheenginemount.Elements:Create/MPC/RBE2.ClickonDefineTerms.Checkth