The effect of binder layouts on the sheet metal formability in the stamping with Variable Blank Holder Force

Flat-shaped and cone-shaped binders, used in the stamping with Variable Blank Holder Force (VBHF), are compared in this study by Finite Element Method (FEM) modeling and verified by experiments. Rigid shell and solid elements are used to model the binders in the VBHF forming simulation. Split has been detected with the rigid shell modeling, which is inconsistent with the experiment. Therefore, the solid element modeling is more accurate to simulate the stress transmission from the cushion cylinder to the binder, which therefore improves the accuracy of the stamping formability prediction. The comparison between the stamped parts with the two binder layouts indicates the cone-shaped binder is more beneficial to the VBHF controllability and stamping formability improvement.