Crack nucleation and propagation modeling for lubricated spur gear contacts of rough surfaces

In this study, a rolling contact fatigue model for lubricated gear contacts of rough surfaces is proposed, considering both crack nucleation and propagation stages. A boundary element approach is implemented to describe surface roughness topography effect on near surface stress concentration, with surface tractions yielded from mixed EHL analysis. A fatigue criterion is employed to find crack nucleation position and life. Assuming mode II crack opening mechanism, stress intensity factor range is determined and used to arrive crack propagation life. Through comparisons to experiments, model capability is demonstrated. Simulation results show important roughness effect on crack propagation as well as crack nucleation.

Automated summary

This study proposes a rolling contact fatigue model for lubricated gear contacts of rough surfaces, considering crack nucleation and propagation stages. The model uses boundary element approach to describe surface roughness effect on stress concentration and fatigue criterion to find crack nucleation position and life. Through comparisons to experiments, the model's capability is demonstrated, showing significant roughness effect on crack propagation and nucleation.