An efficient method of analyzing the effect of roughness on fatigue life in mixed-EHL contact

An efficient and comprehensive Macro-Micro-Fatigue approach for analyzing the effect. of roughness on fatigue life in mixed elastohydrodynamic lubrication contact is presented. It involves two macro-micro approaches, one for mixed lubrication analysis and the other for contact stress evaluation. The macro-micro approaches make it possible to efficiently model pressure and film thickness distribution over the entire area of contact, at the same time allowing a detailed account of asperity interaction effects. The three-stage process comprises a dry rough contact solver, a simplified mixed elastohydrodynamic lubrication solver, and a hydrostatic rough contact solver, all of which are presented. Subsurface stresses are calculated and fatigue life is estimated using the Zaretsky fatigue model. Numerical simulations are performed for several cases of point contacts of rough surfaces and results are presented on a comparative basis.