Numerical Simulation of a Ball Impacting and Rebounding a Lubricated Surface

Abstract

The case of a ball bouncing on a flat surface covered by a thin lubricant layer is analyzed theoretically. Both impact and rebound are studied. A Newtonian lubricant and perfect elastic solids are assumed. As long as the ball approaches the flat surface the pressure in the contact increases and a lubricant entrapment is formed at the center of the contact. When the ball begins to leave the surface, cavitation occurs. At the periphery of the contact a pressure spike is formed. Just before the ball leaves the lubricated surface, very high pressure values arise at and near the contact center. These results are compared with the case of nonlubricated impact. It is found that the pressure in the contact at lubricated impact is higher than in the case of dry impact. Due to the elastic and damping properties of the lubricant film and the impacting surfaces, a time delay is observed between the time of maximum impact force and minimum film thickness. Comparing the theoretical results with experimental results, presented by other authors, shows good correlations.