汽车车身零件的冲压成形和碰撞两种仿真对有限元模型网格的要求不同。为了实现不同类型网格模型之间变量的传递,提出了一种基于等参元逆变换的网格变量映射新方法。该方法通过碰撞模型节点在冲压模型中的精确定位和网格模型之间节点变量的插值,将板料冲压过程中材料性能变化后的实际状态变量(如厚度、应力和应变)精确映射到碰撞仿真模型中。将该方法应用于某轿车前保险杠碰撞仿真的结果表明,该映射方法能很好地实现有限元分析的网格前处理,在精确传递网格变量的同时将冲压效应引入碰撞仿真中,从而提高汽车碰撞仿真的效率和精度。
The stamping forming and crash simulations of vehicle body panels have different requirements on the mesh of finite element analysis model.For achieving the transfer of variables between different types of mesh model,a new mesh variables mapping technique based on inverse isoparametric mapping algorithm is proposed,in which the real state variables(such as thickness,stress and strain) of panel after the change in material properties during sheet metal forming process are accurately mapped into the model for crash simulation by accurately locating the nodes of crash simulation model in stamping model and the interpolation of node variables between mesh models.This method is applied to the crash simulation for a car front bumper and the results show that the method can well realize the mesh preprocessing in finite element analysis and accurately transfer mesh variables,while introducing stamping effects into crash simulation and hence improve the efficiency and accuracy of vehicle crash simulation.