Surface roughness modification in elastohydrodynamic line contacts operating in the elastic piezoviscous regime

Abstract

In heavily loaded elastohydrodynamic (EHD) lubrication contacts operating in the piezoviscous regime, the original surface roughness is largely flattened as it enters the conjunction and is replaced by an inlet generated clearance variation. This clearance variation is convected through the contact at the entrainment velocity. It has a spatial distribution that differs (except for rolling without slip) from the original surface and a different amplitude. This amplitude may be smaller or greater than that of the original profile. An analytical solution of this behaviour is presented for contacts operating well inside the elastic piezoviscous regime for the situation where the roughness is relatively small compared with the film thickness. This solution allows the main features of surface roughness modification to be understood and produces results that compare well with the few numerical solutions available.