Springback reduction with control of punch speed and blank holder force via sequential approximate optimization with radial basis function network

Abstract

This paper proposes a springback reduction technique with the control of punch speed and blank holder force (BHF) via sequential approximate optimization (SAO). Springback is one of the major defects in sheet forming and its reduction is a crucial issue for improving product quality. Computer-aided-engineering is one of the helpful tools for predicting springback and widely used in automotive industries. Various approaches are considered for springback reduction, and we optimize the punch speed as well as BHF (variable BHF). Sheet forming simulation is generally costly and time-consuming, and the SAO with the radial basis function network is used to determine the optimal punch speed and variable BHF. The U-shaped forming in NUMISHEET’93 is used in the numerical simulation. The standard deviation of the bending moment is minimized subject tearing evaluated with the forming limit diagram. The punch speed and the variable BHF are taken as the design variables. The validity is examined through numerical simulation.