Evaluation of different FE simulation codes in the stress analysis of extrusion dies

In hot extrusion, die is subjected to complex working conditions as a combination of both high loads and high temperatures. In order to compute the level of damage reached after a fixed number of cycles or the number of cycles to failure, a realistic prediction of the stress entity and distribution is mandatory. In the present work, the comparison of two finite element codes in the predictability of the stress level induced in a die during hot extrusion was presented. The comparison was also supported by experimental investigation. The FE code, DEFORM 3D®, was firstly used to simulate the extrusion process and to predict the force components exerted by the billet on the die. Then, the die stress analysis was performed within the same code. However, only linear tethraedral elements and elastic material model were available. This justified the requirement of a code specifically dedicated to structural analyses in which a wider range of element types and material models could be chosen. Boundary conditions have been transfer between the two FE codes by means of a purposely developed subroutine and the results compared in terms of predicted die deflection and peak Von Mises stress.