Effect of Elastoplastic Thermal Softening on Electrical Contact Resistance Based on the Dual-Iterative Coupling Method

Electrical contact resistance (ECR) affecting the work behavior is a key index to evaluate the electrical contact capacity of electrical connectors. A large number of factors affecting ECR exist, among which elastoplastic thermal softening (EPTS) caused by temperature rise has a significant effect on ECR. Thus, a high-accuracy dual-iterative coupling method (DICM) is proposed to explore the influence of EPTS on ECR. First, according to the characterization results of the real rough surface, a finite element model (FEM) including a rough surface is created, and the contact state is improved by the contact adjustment method to achieve accurate coupling analysis. Second, the grid dimension is optimized to select an optimal mesh size for the contact surface in terms of computational efficiency and accuracy. Then, a refined numerical model is established. Meanwhile, the validity of the FEM is checked by the experimentally measured ECR. Finally, the impact of EPTS on ECR is revealed through the DICM. The results show that the electrical contact interface suffers from apparent temperature rise due to the Joule heating effect, which causes the ECR to decrease in a different degree under two loading conditions when EPTS is taken into account. Therefore, if a numerical simulation is used to predict the ECR, a DICM should be adopted to obtain more accurate prediction results.