Three-dimensional rigid–plastic finite element analysis of non-steady-state shaped drawing process

Abstract

In this paper, non-steady-state shaped drawing processes have been investigated by using the three-dimensional rigid–plastic finite element (FE) method. In order to analyze the shaped drawing process, a method to define a straight converging die by considering a straight die part, a die radius part and a bearing part has been proposed. In addition, the modeling of the initial billet and the generation procedure of the mesh system have been suggested. The three-dimensional rigid–plastic FE simulation has been performed for a square sectional drawing process and its validity has been confirmed by comparison with existing experimental results. Under the same process conditions, the effect of perimeter ratio and drawing stress in the shaped drawing process has been investigated. Also, the effects of process variables, such as the reduction in area and semi-die angle, on drawing stress and corner filling in the drawing process of a square rod from a round bar have been investigated by using the rigid–plastic FE code developed. In order to investigate corner filling, the diagonal ratio is calculated and compared with the results of the FE simulations. Furthermore, limits of the process variables are determined by considering bulging and necking. From the results, an optimal process condition satisfying reasonable corner filling and a minimum value of drawing stress is suggested.