Abstract: Based on the traditional M-B fractal model， the contact fractal model of static friction coefficient with the elastic-plastic deformation was established. At the same time， the model without the elastic-plastic deformation considered was also built as a comparison. The results show that the static friction coefficients with elastic-plastic deformation considered is greater than that without. The static friction coefficient is positively correlated with the normal load and material parameters， but negatively with the fractal scale parameters. For 1.1≤D≤1.5， the static friction coefficient and the fractal dimension are positively correlated， while for 1.5≤D≤1.9， they are negatively correlated.

Key words: joint surfaces, elastic-plastic deformation, static friction coefficient, fractal prediction model, simulation analysis