One Case of a Lubrication Problem for a Line Contact of Elastic Solids with Soft Double Coatings

Abstract

The main goal of this paper is to consider formulation and solution of a lubrication problem based on the expressions for elastic surface displacements derived asymptotically from an exact solution for a loaded double coated elastic substrate which are valid within a certain range of the problem input parameters. Based on that, a new relatively simple numerical model of the behavior of lubrication parameters in a line lightly loaded contact of double coated elastic cylinders has been developed. For simplicity materials and coatings of both cylinders are considered identical. The main part of the elastic displacements of the contact surfaces is represented by simple Winkler like contributions. The problem is reduced to a numerical solution of a system of two transcendent equations performed by Newton’s method. The formulas for lubrication parameters such as distributions of contact pressure, gap, actual velocity of surface sliding, lubrication film thickness, shear stress, coefficient of friction, and contact energy loss were derived and used for specific calculations. Generally, compared to lubrication parameters in the contact of rigid solids without coatings the effect of the double coating resulted in reduced (up to or more) contact pressure, increased contact area and film thickness as well as some reduction of frictional forces and energy losses. Some specific results for the obtained solutions are provided.