Numerical study on fatigue crack propagation behaviors in lubricated rolling contact

The surface initiated rolling contact fatigue (RCF), including pitti ng and micro pitting, is one of the key issues affecting the reliability of tribological components such as gears and bearings used in various devices, for example, aero engines, helicopter transmissions wind turbines and car reducers . In this work, a sur face initiated crack finite element (FE) model which considers the effect of lubricant on crack faces is developed to investigate sur- face initiated RCF using an automatic crack propagating Python script. Different lubricating states, initial crack paramete rs and loading conditions are simulated to analyze the evolution of crack propagation and the stress in- tensity factors. The RCF crack propagation path and life are predicted by employing the maximum tangential stress (MTS) criterion coupled with the s law. A typical RCF failure is predicted in the numerical simulation. Re- sults reveal that the lubricating pressurization dominates the surface initiated RCF. In addition, the initial crack angle has a significant effect on the RCF crack propagation path a nd the fatigue life.