Surface fatigue of gear teeth flanks

This paper presents a new model for simulation of the surface fatigue process in the contact area of spur gears. The model considers the conditions required for the subsurface fatigue crack initiation and then allows for proper simulation of the fatigue crack propagation that leads to the appearance of small surface pits on the contact surface. The process of the fatigue crack initiation is based on the theory of microcrack initiation along inclusion interfaces. The theory of short crack growth together with the finite element method is used for simulation of the fatigue crack propagation from the initial to the critical crack length, when the occurrence of a surface pit is expected. The developed model is applied to a real spur gear pair, which is also experimentally tested. The comparison of numerical and experimental results shows a good agreement. (C) 1999 Civil-Comp Ltd and Elsevier Science Ltd. All rights reserved.