Finite element simulation and model optimization of blankholder gap and shell element type in the stamping of a washing-trough

Wrinkling is the predominant failure and may be eliminated by appropriate control of blank holding force (BHF) in stamping of sheet metal parts. A new scheme for BHF was introduced in order to apply more realistic BHF in simulation. Different blankholder gaps (BHG) were used to simulate the blank holding process. The optimum BHG was determined through a systematic approach. It is found that the wrinkling in the flange region of the blank increases with the augmentation of the BHG. And the BHF varies owing to the variety of the stiffness of the flange sheet metal. Different shell element types based discrete Kirchhoff theory and Mindlin theory were used to simulate the deep drawing process with the optimum BHG. A comparison of the thickness and flange contour between the simulation results and experiment shows that the 4-node thin shell element based discrete Kirchhoff theory is better in the simulation of the sheet metal forming process and also has merit in not requiring much time.