盒形件法兰起皱临界压边力影响规律研究

Study on influencing rule of critical blank holder force of rectangular box flange wrinkling

起皱是盒形件拉深成形中的主要缺陷,而压边力是控制法兰起皱的主要手段。本文采用基于C-B准则的理论解析与数值模拟方法,研究了材料性能和工艺参数对盒形件拉深法兰起皱临界压边力的影响规律。结果表明:材料性能参数中强度系数K、硬化指数n对法兰起皱临界压边力影响较大,而塑性应变比γ对临界压边力几乎没有影响;临界压边力随拉深行程增加而增大,凹模圆角增大时,临界压边力减小,凸、凹模间隙对临界压边力影响较小。

Wrinkling is the major defect in the rectangular box deep drawing, and blank holder force is the main method to control wrinkling. Using C-B criterion-based theoretical analysis and numerical simulation, the influences of materi al properties and technical parameters on the critical blank holder force of flange wrinkling were investigated. The ana lytic and simulation results show that material parameters, K and n, have significant influences on the critical blank holder force of flange wrinkling in the rectangular box deep drawing, but γ-value has a little influence on it. The criti cal blank holder force increases with the punch stroke and decreases with the round corner radius, but it is not related to the clearance between punch and die.