Computational modelling of the surface fatigue crack growth on gear teeth flanks

The paper describes a 2‐dimensional computational model for simulation of the surface initiated fatigue crack growth in the contact area of gear teeth flanks that leads to surface pitting. The discretized model of a gear tooth with the assumed initial crack is subjected to normal contact pressure, which takes into account the EHD‐lubrication conditions and tangential loading due to friction between gear teeth flanks. The model accounts also for the influence of a fluid driven into the crack by hydraulic mechanism on crack propagation. The J ‐integral method in the framework of the finite element analysis is used for simulation of the fatigue crack propagation from the initial to the critical crack length, when the surface material layer breaks away and pit appears on the surface. The model is applied to a real pitting problem of a gear and corresponding computational results in terms of pit sizes correlate well to the development of micropits observed in experimental testing.