The failure of pinion shaft of traction motor is induced by the rotary bending fretting fatigue at the edge of oil groove.In this study

ABAQUS finite element soft was used to simulate the influence of the rounding radius on fatigue life

and SWT multiaxial fatigue criterion is used to analyze the result of structure optimization.The finite element analysis results show that there is a well accord with the result of failure analysis.The SWT parameters are good to forecast the site of fretting fatigue crack initiation.Increasing the rounding radius of oil groove appropriately can improve the fretting fatigue life of the pinion shaft.