Dynamic Analysis of a Torsion Test Specimen Including Heat Conduction and Plastic Flow

Abstract

This paper presents an analysis of a copper torsion test specimen exhibiting a thermal softening instability at a high strain rate. A consititutive relationship derived from test data includes strain hardening, strain rate effects, and thermal softening. This relationship is used to numerically simulate the thermal softening instability. The results of the analysis are in good general agreement with the test data. The numerical technique is based on an explicit finite element formulation for axisymmetric solids. Elastic and plastic flow stresses are determined from strains, strain rates, and temperatures. Heat is generated by the plastic flow stresses and capability is provided to account for heat conduction. The general numerical technique can be used for a wide range of problems involving thermal-mechanical interaction.