フロントサイドメンバーの初期ブランク形状と可変ブランクホルダー力の同時最適化

抄録

In sheet metal forming, area above trimmed line is called “earing”. The reduction of the earing directly affects the material reduction, and then it is important to determine the optimal blank shape minimizing the earing. In addition, it is well known that blank holder force (BHF) has a direct influence on the product quality. A high BHF causes tearing, while a low BHF leads to wrinkling. Therefore, it is important to determine an appropriate BHF through sheet metal forming. Recently, variable BHF (VBHF) approach which BHF varies through the punch stroke has received a lot of attention, and the validity is discussed. This approach can control the material flow into the die, and the product quality is then improved. In this study, optimal blank shape minimizing the earing under tearing/wrinkling design constraints is determined with the VBHF. Numerical simulation in sheet metal forming is so intensive that a sequential approximate optimization (SAO) using the radial basis function (RBF) network is adopted to explore the optimum solution.