Virtual design of hydrodynamic deep drawing of tapered rectangular cups based on FEM

The hydrodynamic deep drawing of tapered rectangular cups is very difficult to simulate using FEM due to very complicated and varying boundary condition between the flange and the die. If the boundary conditions between flange and die are not modeled correctly, the FEM results will differ greatly from the experimental results making it impossible to predict correctly the occurrence of wrinkles and fracture. In this paper a mathematical model is proposed for the liquid flow between flange and die when drawing a tapered rectangular cup using hydrodynamic deep drawing. The proposed model is combined with a general FEM software and the process parameters (die entrance radius, lubrication, blank size and shape) for the hydrodynamic deep drawing of a tapered rectangular box have been investigated. The hydrodynamic deep drawing process has also been investigated experimentally using a hydrodynamic deep drawing unit mounted in a single action hydraulic press. There is a favorable agreement between the FEM results and the experimental results, which proves the FEM combined with the proposed model for the liquid flow can be used effectively to determine the main process parameters.