关键词: 材料合成与加工工艺, 板料成形, 多点拉形, 数值模拟, 弹性垫, 回弹

Abstract: A finite element model was built for the sheet metal multipoint stretch forming (MPSF),its loading mode for the dynamic explicit algorithm was proposed,and the model was applied to the MPSF of a typical part.The numerical simulation of the MPSF for a saddle surface workpiece was performed.The distributions of stress and thickness in the formed workpiece and the effects of the springback after unloading and the nonuniform deformation of the elastic cushion on the precision of the formed workpiece were investigated.The simulation results show that the distributions of stress and thickness in the MPSF workpiece are uniform,the amount of springback after unloading is small,the effect of the nonuniform deformation of the elastic cushion on the precision of the MPSF workpiece is larger than that of the springback.A method based on the iterative corrections according to the numerical simulation results was proposed to compensate the nonuniform deformation of elastic cushion and the springback to enhance the accuracy of MPSF.

Key words: materials synthesis and processing tehnology, sheet metal forming, multipoint stretch forming, numerical simulation, elasticcushion, springback