Optimization of Variable Blank Holder Force Trajectory Using Multi-objective Sequential Approximate Optimization

在板料成形过程中，压边保持器力（BHF）的调节是一个重要的问题。压边力低会引起起皱，而压边力高会引起撕裂。变压边力（VBHF）成形方法是一种具有吸引力的成形技术，它是压边力随冲头行程变化的一种方法。不幸的是，VBHF是事先未知的，并且使用数值模拟来确定VBHF是有效的。针对板料成形数值模拟的复杂性，采用序贯近似优化方法（SAO）进行了研究。确定了避免方杯形件拉深撕裂和起皱的最佳压边力轨迹。因此，一个多目标优化（MOO）的目的是构建。提出了一种序贯近似多目标优化方法，并将其应用于多目标优化问题。通过数值仿真，验证了该方法的有效性.

In sheet metal forming, it is important to adjust the blank holder force (BHF). Low BHF causes wrinkling, whereas high BHF result in tearing. Variable BHF (VBHF) approach that the BHF varies through the punch stroke is one of the attractive forming techniques. Unfortunately, the VBHF is unknown in advance, and the determination of the VBHF using numerical simulation is valid. Numerical simulation in sheet forming is so expensive that a sequential approximate optimization (SAO) is beneficial.In this research, in order to determine the VBHF trajectory, an optimization problem is constructed. We determine the optimal VBHF trajectory to avoid the tearing and wrinkling for square cup deep drawing. Thus, a multi-objective optimization (MOO) is constructed for this purpose. A sequential approximate multi-objective optimization method is developed and applied to the MOO problem. Through numerical simulation, the proposed approach is so effective.