Effect of thermal expansion on thermal contact resistance prediction based on the dual-iterative thermal–mechanical coupling method

This study investigates the effect of thermal expansion on thermal contact resistance prediction, proposing a dual-iterative coupling method (DICM). The contact surfaces in the simulation model are reconstructed based on either the actual measured topography or the hypothetical topography, and a mathematical formulation for numerically predicting the thermal contact resistance (TCR) is established. The DICM includes four steps: first, mechanical analysis is conducted based on the ideal single point contact condition, according to the elastic–plastic constitutive equations. Second, heat transfer analysis is carried out based on the deformed geometry originating from the prior mechanical analysis. Third, another step of mechanical analysis is implemented to consider the effect of thermal expansion with the temperature distribution determined in the second step. Fourth, another step of heat transfer analysis is carried out based on the deformed geometry originating from the second-step mechanical analysis. The conventional prediction method only contains the first and second steps, and is known as the single sequential coupling method (SSCM). The TCRs of two engineering examples are predicted using both DICM and SSIM. The results show that the mechanical–thermal-mechanical–thermal dual-iterative coupling method, i.e., DICM, should be recommended for simulating contact pairs with axisymmetric geometries, while SSCM is suggested for contact pairs with non-axisymmetric geometry.