Fractal model of thermal elasto-plastic contact of rough surfaces

Abstract

Without considering the influence of heat, existing fractal contact models are not applicable to analyze the contacts when the temperature changes. For this problem, the normal load model and the normal stiffness model of thermal elasto-plastic contact of rough surfaces are developed respectively in this paper. The proposed model is based on the normal contact mechanics model of fractal theory of anisotropic and thermal elasto-plastic contact theory which can be used to characterize the rough surface thermodynamic properties. Then the validity of the model is verified. Finally, the influence of main parameters on the total normal load and the whole normal stiffness of thermal elasto-plastic contact at the interface is analyzed by contact simulation. The results show that the total normal load of thermal elasto-plastic contact increases with the increases of temperature. The whole normal stiffness of thermal elasto-plastic contact increases with increasing coefficient of linear expansion, scale factor, temperature difference or fractal dimension, but decreases with increasing fractal roughness. This model expands basic theory and applications of traditional models, and can be used to calculate and analyze the contacts when the temperature changes.

Keywords

rough surfaces / thermal elasto-plastic / asperity / fractal model

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