STUDY ON THE NUMERICAL SIMULATION OF MULTI-STAGE ROTARY FORGING OF A NON-AXISYMMETRIC PART AND THE CAE ANALYSIS OF THE DIE STRENGTH

摘要

Traditionally a rotary forging process is a kind of metal forming method where a conic upper die, whose axis is deviated an angle from the axis of machine, forges a. billet continuously and partially to finish the whole deformation. For the rotary forging process simulation, more researches were focused on simulating the simple stage forming process with axisymmetric part geometry. Whereas in this paper, the upper die is not cone-shaped, and the billet is non-axisymmetric. So the movement of the punch is much more complicated than ever. The 3D FEM simulation models for the preforming & final forming processes are set up after carefully studying the complicated movement pattern. Deformed is used to simulate the material flow, and the boundary nodal resisting forces calculated by the final stage process simulation is used to analyze the final forming die strength. The CAE analysis of the die shows that the design of the final fanning die is not reasonable with lower pre-stress which is easy to crack at the critical corners. An optimum die design is also provided with higher pre-stress, and verified by CAE analysis.