FEM NUMERICAL SIMULATION OF THE WARM AND HOT UPSETTING SLIDING TEST

For bulk forming applications involving friction, the classical Coulomb-Amonton and Tresca-constant friction laws are not representative of the actual phenomenon when large changes in the contact pressure conditions occur. In order to address these issues, alternative friction laws has been proposed in the last decade. The present paper deals with the analysis of the stress distributions during the Warm and Hot Upsetting Sliding Test for further identification of friction parameters. A first part of the paper is devoted to the description of the mechanical and thermal device used at LAMIH for a sliding test at hot temperature with a polished contactor ironing a steel workpiece. Then, the experimental data are compared to numerical results obtained from 3D simulations of the thermo-mechanical ironing test with the finite element method. The last part of the paper presents some comparisons between numerical data obtained by different 3D finite element models on the first hand, and results of the 2D simulations (under plane stress, plane strain and generalised plane strain) and with slip line theory calculus on the second hand.