模面几何修正的回弹补偿方向分析

Analysis on springback compensation direction for die-face adjustment

精确回弹预测的目的是通过数值回弹模拟来修正模面,使得回弹后零件与设计的产品一致,因此,在回弹预测的基础上进行基于数值模拟或逆向工程的模面补偿和工艺调整,甚至修改成形方案和模具结构,仍然是当前降低回弹的主要措施。文章对模面几何补偿方法进行了阐述,对其应用特点、精度和效率进行了系统的对比分析,结果表明,在以转动为主导回弹的情况下,法向补偿具有很高的精度,但运行计算时间较长;在回弹存在大平移的情况下,连线方向补偿则精度较高,且算法简单;而Z向反向补偿法虽然具有算法简单、计算效率高的优点,却不能很好地对模面进行修正。

The main purpose of precise springback prediction by numerical simulation is to adjust the tooling shape for obtaining parts with desired shape. Die surface compensation, technology adjustment or even changing forming scheme and die structure based on springback prediction is now still the effective measure for reducing springback. The characteristics, accuracy and efficiency of various tooling shape design methods based on displacement adjustment （DA） are studied. It shows that when rotation being the main course during springback, the reverse normal compensation method which compensate along normal direction （ND） makes higher precision but with lower computing efficiency. When there is large translation during springback, the reverse displacement compensation method （DD） which compensate along direction connecting corresponding nodes makes higher precision with simple algorithmic. The z direction compensation method （ZD） which compensate along stamping direction makes a lower accuracy but with very simple algorithmic.