Micropitting Fatigue Wear Simulation in Conformal-Contact Under Mixed Elastohydrodynamic Lubrication

Abstract

In this study, a physics-based fatigue wear model is proposed to evaluate the reliability and to predict the life of cumulative micropitting wear for lubricated conformal contacts on rough surfaces. The surface normal load, mean film thickness, and frictional shear traction are simulated by a mixed elastohydrodynamic lubrication (EHL) model for a stress prediction model to calculate the average maximum Hertzian pressure of contact asperities and unit with the statistical contact model and dynamic contact model to obtain the asperity stress cycle number. The wear formula is established through combining a micropitting life prediction model of surface asperities and a mean micropitting damage constant of asperities. The four dominant aspects affecting wear behaviors of the surface contact pairs, working conditions, structure and surface topographies, material properties and lubrication conditions are all taken into account in the model. It is a high-fidelity and comprehensive model that can be used to analyze and optimize the tribological design of rolling–sliding pairs in machinery. The micropitting fatigue wear modeling scheme is validated by comparison of theoretical calculations and available experimental wear data.