薄板成形模拟中切边回弹算法

Trimming springback algorithm in thin sheet forming simulation

为实现薄板成形切边回弹有限元数值模拟,基于冲压成形性分析软件KMAS平台,建立了切边回弹算法。该算法首先采用切边单元自适应模板实现了切边区域网格重构,然后以形函数插值的方式实现了新旧网格变形场量的映射,最后建立简化的线弹性卸载模型,基于静态隐式算法,预测切边回弹的影响。对于NUMISHEET2005提供的国际标准测试零件(某汽车底板横梁拉延件)的切边回弹数值模拟,结果与实验结果基本一致,验证了算法的有效性。

An algorithm was proposed based on KMAS sheet forming analysis platform to simulate the trimming spring back in the thin sheet forming by the finite element method. The mesh relocation in the trimming region was achieved by the self-adaptive template of trimmed element. The deformation field data mapping from the old to the new mesh was realized by interpolation of the shape fuction. A simplified linear elastic unloading model was built based on the static implicit algorithm to predict the effect of trimming spring back. The numerical simulation on the international standard test part,an automotive underbody stretch cross-member, which was prorided by NUMISHEET 2005,was in good agreement with experimental result,validating the effectiveness of the presented algorithm.