Abstract: A new mathematical analysis model and a uniform constitutive equation are introduced after revising Misses yield rules based on the rigid-plastic FEM. The deformation process of the head of cup-rod type parts is simulated using rigid-plastic FEM and the lead parts simulation test is carried out under the ordinary temperature condition taking universal spline shaft as an example. The process of upsetting process, compound extrusion and reverse extrusion are analyzed in details. The distributing results of speed field, stress field and strain field within the deforming bodies are calculated and curves of moving distance and the change of deforming force are given. The connection algorithm method of area weighted average method and volume weighted average method are presented, which ensure the information correctly transferred from the old mesh system to the new one, after mesh-rezoning. The calculating data is proved to be consistent with experiment results.

Key words: Accurate deforming, Cup-rod typed part, Numerical simulation, Rigid-plastic FEM