FE simulation of shape accuracy using the Multi-Point Stretch-Forming process

Multi-Point Stretch Forming (MPSF) is a new technique to form aircraft outer skin parts. In MPSF, the sheet metal is formed over a discontinuous surface of discrete stretching die. The size of punch element of multi-point die, the thickness of sheet metal and the thickness of elastic cushion are the important factors to affect the accuracy of MPSF part. In this paper, a series of numerical simulations on MPSF processes were carried out, and the shape error and the non-uniformity in thickness distribution of MPSF part were analysed. The results show the influences of the punch element size, the sheet metal thickness and the elastic cushion on forming results.