Three-dimensional finite element method simulation of sheet metal single-point incremental forming and the deformation pattern analysis

Further research of the sheet metal single-point incremental forming (SPIF), which is a flexible sheet metal numerical forming method without dedicated dies, has used finite element method (FEM) simulation to analyse the forming principle and the effect of process parameters on the forming. In SPIF, the located region of the blank in contact with the forming tool is formed incrementally along the trajectory. There is no symmetric load and geometry condition, so the FEM model could not be simplified to a symmetrical model and the efficiency of simulation is bad. In this paper, brick elements are used to establish the whole three-dimensional FEM model and a simplified three-dimensional FEM model of a truncated cone and truncated pyramid. Comparison of the simulation results from the two models indicates that both models fit the simulation of SPIF but the simplified model is more efficient. Therefore, based on the simplified FEM model of a truncated pyramid, the SPIF process with different parameters was simulated to study the incremental forming principle. It was found that the deformed blank could be divided into three regions with different deformation patterns and the main character of the deformation could be conceded as a combination of bending and stretching.