Abstract: Based on the dynamic explicit finite element scheme, the forming forces in the sheet metal multi-point forming (MPF) process were formulated.The forming forces for three typical shapes,i.e.cylindrical,spherical,and saddle surface of different materials with different thickness were simulated.The variation histories of the forming force were analyzed.The results indicate that the forming force becomes larger and larger along with the increase contacting punch number during the forming process.The forming force increases evidently with the sheet thickness and the relatively large forming force is needed if the material is stiffer.The forming force for the object with the surface of double curvature is obviously larger than that with single curvature due to the deformation of the former is more complex than that of the latter.These results are significant for choosing MPF press and controlling MPF process to alleviate forming defects.

Key words: sheet metal, multi-point forming, forming force, numerical simulation