Pressure Increase in Elliptical Impact EHL Contacts With Surface Asperities

The phenomena which occur when a spherical steel body impacts a stationary steel plate with surface asperities are discussed through isothermal Newtonian numerical analysis using sinusoidal roughness. The ridges of the sinusoidal roughness produce large local pressures, particularly in elliptical contacts, when constant loads are imposed on the contact by impact. The pressure level is usually larger when the ridges are located along the major contact direction than along the minor contact direction, and increases as the loading speed increases. The high pressure induces a micro-groove in the ridge and the horse-shoe shaped constriction is formed at the ridges locating around the contact edge.