Micro-elastohydrodynamic lubrication of low elastic modulus solids on rigid substrates

It is now recognized that micro-elastohydrodynamic lubrication contributes substantially to the formation of effective lubricating films in synovial joints. In this paper we examine the influence of a single blemish on the bearing surfaces upon film formulation. We also investigate the influence of roughness, amplitude, wavelength and phase angle upon minimum film thickness and report that whereas phase angle has little effect, large amplitude and small wavelength roughness leads to smaller film thicknesses. The overall conclusion is, nevertheless, that micro-elastohydrodynamic lubrication is an exceedingly effective mechanism of lubrication under all the circumstances examined. The influence of conjunction kinematics, ranging from pure rolling to the translation of either the rough or smooth surface, is also considered.