Numerical analysis of surface fatigue crack growth using FEM method

The paper describes a two-dimensional computational model for simulation of surface fatigue crack growth in the contact area of gear teeth flanks. The discretised model of gear teeth is subjected to normal loading (Hertzian contact pressure), tangential loading (friction between gear teeth flanks) and additional external contact forces that arise from the EHD-lubrication conditions. For more realistic simulation of the fatigue crack growth it is necessary to consider the moving gear teeth contact which is simulated with different contact loading configurations. The Virtual Crack Extension method (VCE) 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 comparison of computational and experimental results shows that the proposed model reliably simulates the surface fatigue crack growth under contact loading and can he used for computational predictions of surface pitting for various contacting mechanical elements like gears, bearings, wheels, etc.