A Coupled-Field Simulation of an Electrical Contact during Resistance Welding

This paper deals with the study of the electrical contact between two OFHC copper pieces in the assembling process of resistance welding. A coupled-field simulation is developed with the ANSYS software to observe the coupled phenomena - mechanical, electrical and thermal - occurring in the contact when a high current (up to 100 kA) flows through it. It takes into account the dependence of the material properties versus temperature. In order to weld the two pieces with the minimum energy, the welding process involves a piece with projections and a plane one to create strictions on the contact area and so increase the heat generated by Joule effect. The goal of this modelling is to take into account the roughness of the contact area. A parametric study is realized with an experimental welding device. The changing parameters are the contact force, the welding time and the current intensity. The results from these experimental tests are compared with the calculated ones to validate the simulation. The comparison shows a consistency of these results. They also allow to set up a model of the contact resistance during the complete duration of the resistance welding process.