建立了全承載式大客車車身骨架的有限元模型，對車身骨架結構進行了振動模態和靜力學分析。然后對車身骨架結構進行設計參數靈敏度分析，得出車身骨架扭轉剛度和一階扭轉頻率對各部件設計參數的靈敏度。在此基礎上，以車身骨架桿件厚度為設計變量，通過兩階段結構優化設計，在整車骨架質量增加很少的條件下，提高了整車結構的扭轉剛度和一階扭轉頻率值;同時，一輪懸空工況下的整車結構應力峰值明顯下降，應力分布更加均勻，整車骨架結構設計更為合理。
關鍵詞:大客車;車身結構;有限元分析;優化設計
[A bst rac t]Afiniteelementmodelforthebodyframeofintegralbusisbuiltandthevibartionmodalanalysis
andstaticanalysisare PerfOrmedonbodyframestructure.Thenlhesensitivitiesoftorsionalstifnessandfirst一order
torsionalvibrationfrequeneytodesi，paramete鄺ofbodyframeare obtainedbysensitivityanalysis.onthisbasis
twostagesofoptimizationdesi，are performedwiththesectionsizesofframebarsasdesignvariabIes.Asaresult，
thetorsionalstifnessandl吐ordertorsionalvibrationfrequencyareraisedwithonlysIightincreaseinframemass，In
addition，thepeakstressofthewholebodystructureintheconditionofonefrontwheelsuspendedis腳atlyreduced
withevenerstressdistributionandthedesignofwholebodyframestructuretendstobemorerational.
Ke yw or ds:bsu;bodystructure;FEA;oPitmaldesign