Rolling contact fatigue of coupled EHL and anisotropic polycrystalline materials

Fatigue failure in rolling element bearings (REBs) is a highly stochastic process influenced by the anisotropy of bearing material and the coupled elastohydrodynamic lubrication (EHL). In this investigation, the finite element method (FEM) was used to couple the effects of anisotropic bearing steel microstructure and EHL. This FEM framework was used to investigate RCF failure in line EHL contacts. The granular bearing steel microstructure was modeled using Voronoi tessellations, where each grain is modeled as cubic elastic material to simulate anisotropy. Continuum damage mechanics and cohesive element method were used to model RCF crack evolution along the grain boundaries. The damage accumulation in the cohesive grain boundaries was used to model the crack initiation and propagation and estimate fatigue life. The life predictions from the model show the effect of anisotropy and EHL in RCF and exhibit a strong stochasticity that is characteristic of bearing failures observed in the open literature.