From Continuous to Molecular Scale in Modelling Elastohydrodynamic Lubrication: Nanoscale Surface Slip Effects on Film Thickness and Friction

The aim of this article is to propose an original approach in modelling elastohydrodynamic lubrication (EHL), combining a classical model derived from continuum mechanics and a nanoscale investigation carried out by Molecular Dynamics simulations. In particular, nanoscale slip is numerically quantified and a semi-analytical model for surface slip variation with pressure, film thickness and sliding velocity is presented. A composite model involving both continuum mechanics and nanoscale effects allows for a better understanding of dimple formation and offers a new basis towards a physically based friction prediction. This tentative represents a new direction towards a more realistic modelling of lubricated contacts with ultra thin film for the present industrial needs.