On the electrical contact resistance model of rough surfaces based on multi-physics modeling

Electrical contact resistance (ECR) serves as a critical performance parameter for assessing the reliability and durability of electrical contact systems. Accurate ECR prediction remains challenging due to three predominant factors: the interface complexity introduced by surface roughness, the presence of multi-physics coupling phenomena, and the nonlinear nature of elastoplastic deformation characteristics. Although classical analytical models, such as Holm’s theory, Timsit’s formulation, and Greenwood’s approach, have provided fundamental insights, their practical utility is often constrained by oversimplified assumptions and inherent limitations in addressing real-world operational complexities. This paper presents an efficient numerical method for predicting the ECR of rough surface electrical contacts by incorporating the influences of both multi-physics coupling and elastoplastic material deformation. For Gaussian rough surfaces, the proposed numerical approach systematically quantifies ECR across a wide range of fractal parameters and loading conditions. A comparative analysis of this method against existing ECR models reveals that the Greenwood-based predictions exhibit significant deviations under a high-load condition. Based on the predictive data, this study establishes a novel and accurate model that quantifies load-dependent ECR of Gaussian surfaces. To verify the developed ECR model, electrical contact experiments were conducted. This new model enables rapid and reliable ECR estimation, providing a valuable tool for the design and optimization of electrical connectors.