An efficient method for electro-thermo-mechanical coupling effect in electrical contact on rough surfaces

•A BEM method for multi-physics electrical contact on rough surface is presented.•Both film resistance and constriction resistance are conducted in the model.•Linear relationship between contact conductance and contact stiffness is verified.•Probability density function of contact pressure and temperature rise is studied. In this study, a numerical strategy based on the boundary element method (BEM) is developed to simulate the electrical contact behavior on rough surfaces. By using the Fourier transform, the solutions of the electric potential, temperature rise, and displacement fields in the Fourier space are derived with finite boundaries, in which the electro-thermo-mechanical coupling effect is considered. With the consideration of the contact condition, an iterative algorithm is proposed to seek the solutions of rough surface electrical contact under a given contact force and total electric potential drop. The contact pressure, real contact area, electrical contact resistance, electric current, and temperature rise distribution are predicted. For the validation, the electrical contact results of a spherical punch-half space contact and a rough surface-elastic substrate contact are calculated based on the finite element method. The good agreement between the results from the BEM-based method and the finite element method indicates the accuracy of the presented method. Then, the effect of the total electric potential and the thermal expansion on the electrical contact behavior, the relationship between the contact conductance and contact stiffness, and the probability density function of the contact pressure and temperature rise distributions are evaluated using the proposed method.