Analysis of Rolling of Bars by the Energy Method Using Finite Element Division : (Analysis of Square-Oval Pass)

Abstract

In the field of bar rolling, very little theoretical researches has been performed, because the flow of the material in bar rolling is complicated. Recently, we proposed a new energy method using finite element division ; this method was applied to the analysis of the flow of the material for two types of bar rolling : equare-diamond pass and round-oval pass. However another important type of bar rolling exists : square-oval pass. In this type, the side regions of the material are reduced earlier than the central region, whereas the central region of the material is reduced earlier in the former two types. Thus, the flow of the material of this type differs greatly from that of the former types. In square-oval pass, the material is deformed inhomogeneously, and the degree of freedom of the velocity fields must be increased for precise simulation of the flow of the material. In this paper, we have improved the method to lessen computation time and memory requirements. This method is then applied to the analysis of the flow of the material in square-oval pass and reasonable results are obtained for rolling properties such as width spread, strain rate distribution, folding of stress-free side surface, and others.