絞りスピニング加工における<br>破断発生メカニズムとその予測手法

Abstract

We have developed a numerical simulation technique of a spinning draw process using a dynamic explicit Finite Element Method (FEM) for evaluating formability. Oyane’s equation for the ductile fracture criterion was applied. In order to shorten computation time, the velocity of die roller movement and the velocity of die rotation of the material are increased in the analytical model. If the velocity of the die roller in the axial direction is increased, the velocity of die rotation is adjusted to obtain the same extent of damage as that in the actual spinning draw process. An accurate evaluation of fracture initiation in a spinning draw process can be performed within a short computation time. It was confirmed that numerical simulation is a useful tool for investigating the formability of a spinning draw process. Finally, we have developed an optimization method for forming parameters using the response surface method on the basis of the finite element analysis (FEA) results of a spinning draw process. In this study, we also presented the application of the proposed analytical model for verifying whether the optimized condition realized high-quality products without fracture.