Inhibitory effects of a flexible steel pad on wrinkling in multi-point die forming

A flexible steel pad was applied in multi-point die forming to inhibit wrinkling from occurring in sheet metal, which is based on the idea of sheet metal flexible forming method. In numerical simulations, three multi-point die forming processes, namely without a polyurethane cushion, with a cushion, and with a flexible steel pad, were carried out for a complex three-dimensional part. Comparison of simulation results indicates that adding the flexible steel pad could effectively improve the stress and strain distribution, forming precision, and surface quality as well as effectively suppressed the occurrence of wrinkles and dimples. Experimental results of the three forming processes are consistent with the simulations, which proves the inhibitory effect of the flexible steel pad on wrinkling and the accuracy of the numerical simulations.