Determination of optimal shapes for the stampings of arbitrary shapes

The sensitivity method has been used in this study in order to find initial blank shapes which will result in the desired shapes after deformation. By assuming the final shape to be the drawn cup with uniform trimming width at the flange, the corresponding initial blank which gives the final shape after deformation has been found. With the aid of a well-known dynamic explicit analysis code Pam-Stamp®, shape sensitivity has been obtained. To obtain the shape sensitivity numerically, a couple of deformation processes have to be analyzed at each design stage. Drawing of trapezoidal cup, oil pan, and AUDI front door panel, the benchmark test problem of Numisheet ’99 have been chosen as the example. At every case the optimal blank shape has been obtained after only a few steps of modification without any assumed deformation path. With the predicted optimal blank, both computer simulation and experiment are performed. Excellent agreements are obtained between simulation and experiment in every case. Through the present investigation, the sensitivity method is found to be very effective in the design of arbitrary shaped drawing processes.