曲面扁壳类汽车覆盖件刚度的控制机制研究

摘要

为有效控制和提高汽车覆盖件的刚度,以能够代表汽车覆盖件曲面特点的柱面扁壳件和双曲扁壳件为研究对象,采用数值模拟和试验相结合的方法,深入分析零件在成形过程中拉深筋、拉深深度及压边力对刚度的影响规律,并通过分析扁壳件成形后应力应变分布特点,揭示工艺条件对刚度的影响机制.研究表明：刚度随着压边力的增大而增大,增设拉深筋有助于提高曲面扁壳件的刚度;刚度随着拉深深度的增加而增大;工艺条件的改变可以增大塑性应变量,减少残余应力,并减少回弹,提高刚度.%To control and improve the stiffness of automotive body panel,a study is set up with numerical simulation and experimental approach based on cylindrical shallow shells,double-curved shallow shells,which can represent the automotive surface characteristics.The relation between forming process,such as blank holding force(BHF),draw bead,draw depth and stiffness is obtained.The stiffness increases with the increasing of blank holding force and draw depth,and it is improved with the set of draw bead.The influence of process conditions on stiffness is revealed by analysis of stress and strain distribution characteristics of shallow shells.The plastic strain is increased and the residual stress and springback are all reduced with the changes of process condition,and the stiffness is improved.