Electrohydrodynamic lubrication model in point contacts with consideration of surface coating

An electrohydrodynamic lubrication (EHL) model in point contacts with consideration of surface coating is presented. The disturbance displacement caused by the coating on the surfaces is calculated using the finite element method (FEM). The effects of coating's hardness and thickness on oil film pressure, thickness, and subsurface von Mises stresses are investigated. The results show that hard coating causes a significant increase in the oil film pressure, while soft coating has the opposite effect. A significant stress concentration occurs at the subsurface when there is a hard coating. And when the thickness of the coating reaches a certain value, the subsurface stress reaches its maximum. While when there is a soft coating, the maximum stress on the subsurface is slightly reduced.