Analysis of an equivalent drawbead model for the finite element simulation of a stamping process

In order to facilitate the three-dimensional finite element analysis for the stamping process, an equivalent drawbead model was adopted to simulate the restraining effects produced by the real drawbead. In the present study, the restraining force exerted by the real drawbead was first computed by the finite element simulation, and the optimum pseudo drawing speed and mesh sizes for both the drawbead and sheet metal employed in the computation were determined through a systematic approach. The computed restraining force was then assigned to a regular mesh which replaced the mesh of the real drawbead. This constitutes the equivalent drawbead model, which avoids the extremely fine mesh required to describe the deformation of sheet blank in the drawbead area. In consequence, a huge amount of computation time can be saved. The accuracy of the finite element simulations using the equivalent drawbead model was validated by both the experimental data and the theoretical predictions.