Simultaneous Optimization of Variable Blank Holder Force Trajectory and Tools Motion in Deep Drawing via Sequential Approximate Optimization

Abstract

In this paper, variable blank holder force (VBHF) trajectory and tools motion are optimized simultaneous by a sequential approximate optimization (SAO) with radial basis function (RBF) network. In deep drawing, wrinkling and tearing are major defects that are strongly avoided in sheet forming. These defects are then taken as the objectives directly. The Forming Limit Diagram (FLD) is employed to evaluate the risk of wrinkling and tearing quantitatively. The design variables are taken so as to optimize the VBHF trajectory and the tools motion simultaneously. In numerical examples, a square cup deep drawing is handled. The optimum result shows that simultaneous optimization of the VBHF trajectory and the tools motion result in the successful deep drawing. In particular, the forming energy can be drastically reduced, in comparison with only the optimization of VBHF trajectory. This result implies that the simultaneous optimization of both VBHF trajectory and tools motion will be effective approach to reduce the forming energy.