Design of Process Parameters in Deep Drawing of Sheets to Improve Manufacturing Feasibility

The aim of this investigation is to present a numerical procedure combining a simplified finite element inverse approach (I.A.) for the rapid simulation of the stamping process with mathematical programming technique (BFGS method) to optimize the stamping process design. Our objective is to optimize the quality of the final workpiece, by minimizing the risk of rupture and wrinkles. The design variables of this problem are the drawbead restraining forces, and the material parameters such as the strain hardening exponent n (Hollomon law) and the Lankford anisotropy coefficient in relation with the Forming Limit Diagram (FLD). The optimization procedure developed has been applied for the square cup of Numisheet’93 and the Renault/Twingo dashpot cup. The satisfactory results demonstrate the usefulness of this automatic optimization procedure in the preliminary design of deep-drawing process.