New upper bound solutions for ideal metal flow through ideal dies

摘要

This paper presents new upper bound solutions for analysis of ideal flow through ideal dies. Die design is both an art and science. Extensive theoretical and experimental research has been carried out in the past to improve die design and the flow of material through it. The most widely used techniques for flow analysis has been the finite element technique, slab method or the upper bound technique. In case of three-dimensional analysis the finite element technique is very time consurning and requires some level of skill on the part of the user during meshing and analysis. The slab method is very inaccurate for complex geometries. The new upper bound formulation and program presented here, incorporates the correction for the velocity profile and the slip at the wall using the friction coefficient. The modified method was coded using the C language and teh results are compared to the finite element solution for the same die geometry. The new upper bound solution for extrusion was significantly faster and compared well with the finite element method. The new solution will be incorporated into the existing die design package STREAM in place of the slab method currently employed.