A three-dimensional steady-state finite element analysis of square die extrusion by using automatic mesh generation

Abstract

Steady-state finite element analysis is made for three-dimensional hot extrusion of sections through square dies by using an automatic mesh generator which can generate three-dimensional meshes by shifting two-dimensional meshes. In industrial practice, the design of extrusion dies is still an art rather than science, especially for complicated profiles, because the die design for a new extrusion is developed from previous experience and in-plant trials. The objective of this study is to develop a steady-state finite element method for hot extrusion through square dies, and to provide a theoretical basis for an optimal die design and process control for the extrusion technology. In the present investigation, steady-state assumption is used for both the analyses of deformation and temperature. The analysis of temperature distribution includes heat transfer, and is carried out by decoupling from the analysis of deformation. Convection link element is adopted for the heat transfer analysis between the billet and the container, and also between the billet and the die. Computations are carried out for solid and hollow extrusion of several sections. The present method of analysis has been shown to provide good results comparable with the non-steady-state method with reduced computation time. Distributions of temperature, effective strain rate, velocity and mean stress are discussed for effective design of an extrusion die. (C) 1999 Elsevier Science Ltd. All rights reserved.