Theory of Life Prediction of a Viscoelastic Lubricating Surface Film

A solid lubricating surface film is modeled as a general linear viscoelastic material. The appropriate governing equations are solved for the displacement of such a thin film under repeated loadings. The predicted transient motion of the surface is monitored. The gradual diminution of the lubricant film thickness under repeated loadings is considered film wear. The failure of solid lubricating film occurs when the existing thickness is to the same order of magnitude as the substrate surface roughness.