Fractal Prediction Model for Normal Contact Damping of Joint Surfaces considering Friction Factors and Its Simulation

To research the dynamic characteristics of the joint surfaces from the microperspective, the fractal prediction model of the normal contact damping of joint surfaces is established based on the solid-gap-solid contact model which was proposed by the author, tribology theory, and contact fractal theory. And the kinetic model of joint surfaces is improved to a certain extent. The influences of actual contacting area, friction coefficient, and the fractal dimension on the normal contact damping are revealed by the research of numerical simulation. Simulation results show that the normal contact damping of joint surfaces decreases to a constant value with the increase of actual contacting area, increases with the increase of friction coefficient, and decreases with the increase of fractal dimension. Actual contacting area influences the location of the turning point of the C-n*-mu (critical friction coefficient), and the critical friction coefficient increases with the increase of actual contacting area. Normal damping coefficient of joint surfaces continuously decreases with the increase of fractal dimension and the difference of magnitude exists between normal contact damping coefficients with different fractal dimension values.