Effect of Force Correction Algorithm Arising from Change of Tool Normal on Sheet Metal Forming Simulation

Abstract

Treatment of contact problems between sheet and tools is one of the most difficult problems to deal with in sheet metal forming simulations. This paper describes a new algorithm for the discretization of the change of the “averaged tool normal” which is calculated by averaging the normals defined on all adjacent elements. The proposed algorithm was implemented into STAMP3D, which is a static explicit program dedicated to sheet metal forming simulations. Simulations of draw bending process were performed and the normalized norm of the non-equilibrated forces due to the change of the tool normals was compared between the original result and the result obtained with the proposed algorithm. It was found that the normalized norm of the non-equilibrated forces was drastically reduced by applying the proposed algorithm. This result shows the improvement of the accuracy of the simulation and the efficiency of the proposed algorithm.