Influence of surface topography on three-dimensional fractal model of sliding friction

The purpose of this paper is to establish a three-dimensional model of sliding friction and to study the influence of surface topography fractal parameters on the model. Firstly, the analysis of the contact between two asperities is completed, for according to the classical molecular-mechanical friction theory, the sliding friction among rough surfaces should be the sum of mechanical force and molecular adhesion. Then based on the fractal theory, the three-dimensional fractal model of sliding friction is deduced. Finally, the influence of the maximum contact area of asperity al, the fractal roughness G and the fractal dimension D on the sliding friction is analyzed by a simulation example, and the analysis results show that the sliding friction F has positive correlation with al and G, and there is an optimal fractal dimension D which minimizes F. The study of the paper can be used to explain the existing experimental results and the friction theory reasonably.