Influence of surface topography on viscoplastic asperity lubrication

The load support generated by sliding asperities, with a lubricant which is newtonian up to some critical shear stress and thereafter behaves plastically, is calculated. Wedge-shaped and cylindrical asperities with their crests normal to the sliding direction are considered. It is found that low load support and potential failure occur with the combination of high roughness and small asperity spacing or with low roughness. This is in agreement with the experimental results of Hirst and Hollander.