Implementation of Plastic Thickness Strain in an Equivalent Drawbead Model based on a Penalty Constraint Method

Drawbeads are applied in the deep drawing process to improve the control of the material flow during the forming operation. These drawbeads can be replaced by an equivalent drawbead in simulations of the deep drawing process. In this paper the implementation of an equivalent drawbead model in a finite element code is described. This equivalent drawbead takes not only the drawbead restraining force into account, but also the plastic thickness strain and the drawbead lift force. Simulations of the deep drawing of a rectangular product are performed to test the equivalent drawbead performance. For verification, the product is stamped as well to obtain experimental information. It can be concluded that the simulations, including the new equivalent drawbead model, show a very good correlation with the experimental results when an elastic plastic material model is used.