Finite element analysis of the influence of the restraining force in the draw bend test

Draw restraining force is used in sheet metal forming processes to regulate material flow and control springback in the parts. In this paper, the influence of draw restraining force on springback behaviour of dual phase steels is investigated, through numerical simulations of the draw bend test. Three grades of dual phase steels are submitted to different normalized back forces in the range from 0.5 to 1.1 of the initial yield stress. All simulations were performed with the DD3IMP in-house code. The study highlights the importance of an accurate modelling of the isotropic work hardening of dual phase steels for an accurate springback prediction.