Draw-bead simulation by an elasto-plastic finite element method with directional reduced integration

An elasto-plastic finite element method is adopted to simulate draw-bead formation and draw-in process through the draw-bead. The finite element method code has to deal with a proper contact algorithm and a stress evaluation algorithm, since the sheet metal undergoes large deformation and rotation with severe geometric changes. The simulation of draw-bead formation produces the distribution of stress and strain in deformed sheet metal along the bead as well as the punch force of a draw-bead. It also pro, ides the resultant elongation of the sheet in the cavity region, which is the fundamental information as a boundary condition to analyze the complicated binder-wrap phenomena.