Abstract:A fractal model of thermal contact conductance between two cylinders’ joint surfaces considering the elastic deformation, elastic-plastic deformation and plastic deformation was established using three-dimensional fractal theory. The influence of fractal dimensions, fractal scale parameters, cylinder curvature radius and contact type on thermal contact conductance is analyzed using numerical simulation. The results indicated that: The thermal contact conductance increases with the increase of the fractal dimensions and decreases with the increase of the fractal scale parameters; The thermal contact conductance of the internal contact is larger than that of the external contact with the same parameters; In addition, when the curvature radius of one cylinder is fixed, the thermal contact conductance increases with the increase of the curvature radius of the other cylinder. The model provides a theoretical basis for the research of thermal contact conductance of gears or other curved surfaces.