Quality Function Approach to Design and Optimization of Stamping Process: Application to an Industrial Case

In the frame of reduction of design costs and lead-times, process engineers need assistance in their research of a reliable and robust stamping process. Today, in order to reach the best quality product, we have to calculate interactively a large number of solutions, which means several designs (CAD) and then several finite element analyses. In this paper, we present how we combined a finite element analysis program with mathematical programming techniques to optimize the stamping process design. With this approach our objective is to optimize the quality, by minimizing the risk of rupture, wrinkles and unstretched areas. The design variables of this problem are the drawbead forces, the shape of die addendum and the shape of the blank holder surface. The methodology developed has been applied in the early design phase of the stamping process for the front fender of Renault Kangoo. Both restraining conditions and die addendum features have been chosen as design variables. This optimization has taken 5 times less workload and lead time than the equivalent work, carried out with traditional methods.