Research on the forming accuracy in the multi-point forming procedure based on the discrete steel pad positioned/reset by a polyurethane pad

A spherical surface with a forming radius of R400 was adopted as the research object to investigate improving the forming accuracy by using a discrete steel pad in multipoint die forming. The numerical simulations of three different forming processes, namely without cushion, with a polyurethane cushion, and with a discrete steel pad, were carried out via the Abaqus finite element analysis software. The numerical simulation results show that using a discrete steel pad in multipoint die forming can effectively suppress wrinkling, straight edge and dimpling defects, and improve the forming accuracy. The experimental results for the three forming processes are consistent with the simulations’ results, which demonstrate the improvement in the forming accuracy that results from using a discrete steel pad in multipoint die forming while simultaneously proving the accuracy of the numerical simulation.