FEM numerical simulation of the warm and hot upsetting sliding test

Abstract

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.

Phenomena of tool adhesion at elevated temperature in V-groove friction test of AA7075

“…However, the compression ratio of this test is only about 50 percent and a friction test that allows a larger surface area expansion ratio is needed. In addition, reports of friction tests simulating hot extrusion and hot forging include the two-cylinder crossed friction test by Kalin et al [5][6][7] and the Warm and Hot Upsetting Sliding Test (WHUST) by Dubar et al [8][9][10] as examples of hot friction tests. Although these have been reported, there are few examples of friction tests simulating hot extrusion and hot forging.…”

A Study of Friction Model Performance in a Skew Rolling Process Numerical Simulation

“…Due to the difficulty of characterising the contact in a real process, many studies have approached the problem using laboratory tests. For this purpose, test methods such as upsetting-sliding [4,5], T-shape compression [6], Pin-on-disc [7] or the widespread ring compression [8,9] have been used. However, Joun et al [8] concluded that the friction evaluation curves achieved by means of the ring compression test were irrelevant for the hot rolling process that they analysed.…”