Lubricant Film Thickness Behavior in Point Contacts Considering the Effect of Plastic Deformation
EHL is a common mode of fluid film lubrication found in many machine elements. Upon many years of research, its lubricant film formation mechanism has been well understood, and some curve-fitting formulae have been widely used. However, engineering materials are usually not ideally elastic, and plastic deformation often occur in many cases, possibly influencing the lubrication characteristics considerably. Therefore, the lubricant film thickness behavior in reality may not exactly follow the conventional EHL theory. In the present study, the plasto-elastohydrodynamic lubrication (PEHL) simulations are conducted for different materials properties in a wide range of operating conditions, and obtained film thickness results are compared with those from the EHL formulae by Hamrock and Dowson that do not consider the effect of plastic deformation. Based on this the lubricant film thickness prediction method taking into account the plastic deformation is discussed.