The Prediction and Experimental Study of Bending Fatigue Life of Carburized Gears

Tooth bending failure, one of the gear’s most dangerous failure modes, is caused by alternating bending stress at the tooth root. The fatigue process is divided into crack initiation and crack propagation periods. In this paper, single tooth bending fatigue tests are conducted under a stress ratio of 0.05. Crack initiation life is predicted by the strain-life method. Material gradients and residual stresses are taken into account in the above process. The crack propagation life is predicted by linear elastic fracture mechanics. The Paris equation is used to simulate the fatigue crack growth. Finally, the total bending fatigue life can be estimated. Predicted fatigue life and failure locations show good agreement with the experimental results. Graphical Abstract