The Contact Fatigue Life Evaluation According to Contact Surface Removal

Railway wheels and axles have been one of the most critical components in a railway vehicle. The service conditions of railway vehicles have became more severe in recent years due to the increase of the speed. It is very important to evaluate the reliability of wheels with regard to safety, because wheel failure can cause derailment with loss of life and property. One of the major reasons of the railway wheel damage is the contact zone failure by wheel/rail contact. One of the methods for preventing the failure and increasing the fatigue life is to grind periodically the contact surface before reaching the failure. The increase or decrease of the contact fatigue life by the surface removal of the contact surface were shown by many researchers. However, the reason why fatigue life increases or decrease has not been investigated obviously. In this study, the effect of the surface removal depth on the contact fatigue life for a railway wheel is evaluated through the employment of rolling contact fatigue tests and the finite element analysis. It is found that the contact fatigue life increased with the removal depth. But in the case that the removal depth is greater than the optimal depth, the contact fatigue life decreased. It seems to be obvious that the residual strain is the main factor determining the fatigue life according to the removal depth