Numerical Simulation on Weld Joint Offset for Tailor-Welded Blank in Multi-Point Forming

Multi-point forming (MPF) is a novel manufacturing technique for three-dimensional sheet metal. It employs two reconfigurable element groups to approximate the continuous upper and lower solid dies. With the technique, rapid fabrication of 3D sheet metal part is realized. In this paper, to investigate the feasibility of the multi-point forming for the tailor-welded blank (TWB), the explicit finite element model on TWB in MPF is established, then spherical surface TWB is selected as an example to simulate weld joint offset defect in the process of MPF, and finally method to suppress generation of defect is proposed. The simulation results show that in MPF for spherical surface part, weld joint removes to thick blank direction in zone of expanding and suspending, but to think blank in zone of blank holder; weld joint offset can be controlled effectively by adopting stepped blank holder and applying proper blank holder force.