On roughness attenuation in elastohydrodynamic lubricated line and circular contacts

Abstract

The commonly accepted “roughness attenuation” theory offers a description of the deformation of surface features as they travel through elastohydrodynamic lubricated contacts, based on the Boussinesq half-space approximation. Through a finite element model, incorporating surface features into the contact geometry (which cannot be done with the half-space approach), this work reveals three shortcomings in the theory. First, contact pressures are assumed normal to the substrate rather than the surface features lying on it. Second, it uses reduced solid properties that are invalid in the presence of surface features. Third, it does not account for the deformation of the features themselves. A correction procedure is devised, allowing for the theory to be rectified, without the need to incorporate surface features into the contact geometry, which can be computationally prohibitive.