基于有限元的汽车发动机隔热罩拉延模的开发

使用基于动态显式算法的商业软件LS—DYNA建立了某汽车发动机隔热罩拉延成形的有限元模型．通过所建立的有限元模型分析了压边力对拉延成形的影响．有限元分析结果表明，没有合适的能同时有效抑制板料皱折和破裂的压边力．因此，文中采用拉延筋和压边力来共同控制拉延成形，并通过有限元分析比较了几种典型的拉延筋布置方案，选择其中最有效的一种进行试冲试验．结果表明，有限元分析结果和试验结果吻合较好，该拉延筋的布置能消除工件的皱折，同时避免过度变薄．有限元分析有助于工程师在设计初期制定正确的设计方案，使该产品的开发周期从过去的12周缩短为4周．

Development of Drawing Die for Heat-Shield Panel of Automobile Engine Based on Finite Element

A finite element model describing the drawing process of the heat-shield panel of automobile engine is established by using the commercial dynamic explicit code LS-DYNA.By the established model,the effect of BHF(Blank Holder Force) on the drawing process is analyzed,with the results showing that no appropriate BHF can effectively restrain the severe wrinkling and folding as well as the tearing.Therefore,drawbead is employed together with BHF to control the drawing process,and several typical layouts of drawbead are analyzed and compared via FEA(Finite Element Analysis),with the most effective one then being applied to stamping experiments.The results indicate that the results of FEA accord well with those of the experiments,and that the proposed drawbead layout can eliminate the severe wrinkling and folding as well as avoid the excessive thinning.By the FEA,engineers can make correct decisions at the early design stage,and the development cycle of the drawing die for the panel shortens to 4 weeks from the past 12 weeks.