A SIMPLIFIED METHOD FOR THE SIMULATION OF COLD-ROLL FORMING

A kinematical approach is proposed in this paper for predicting the op timal shape and the deformed length of a metal sheet during cold-roll forming, before the first roll stand. The middle surface of the sheet is described as a Coons patch depending on one geometrical parameter. A velocity field is then defined on this surface so that the plastic w ork rate depends only on this single geometrical parameter. Its minimi zation gives the optimal shape for a strain-hardening rigid-plastic ma terial. This approach has been implemented on a workstation, and it al lows a very fast simulation of the process. Moreover, this method can be extended to different shapes, and the whole process including sever al roll stands can also be calculated.