A mechanical, electrical, thermal coupled-field simulation of a sphere-plane electrical contact

The purpose of this paper is to present a numerical simulation of the behaviour of a sphere-plane electrical contact when a high current flows through it. A sequential coupling allows to study the interactions between mechanical, electrical and thermal phenomena occurring under a high current flow (a few kA). The structural deformations and the voltage and temperature distributions are computed with the help of the finite element method via the ANSYS software. The 2D axisymmetric geometry considers a smooth sphere pressed on a smooth plane. The model takes into account the dependence of material properties versus temperature (Young's modulus, electrical and thermal conductivities, specific heat, coefficient of thermal expansion...). The influence of several parameters such as current intensity and frequency, contact force and duration of the current flow on the potential distribution has been studied. As they are coupled, all phenomena are affected by heat variations and every phenomenon has an effect on all others and so on. In some particular conditions, analytical calculations make it possible to validate the simulation. Comparisons with experimental results are realized with several contact forces.