| Fatigue is a major failure form of a body under repeated rolling contact. It is often found in bearings and rail/wheel contact. The current effort is the development of a research approach for the rolling contact fatigue life prediction.The approach consists of two parts: the rolling contact stress was analyzed first, and then the fatigue damage analysis based upon the calculated elastic-plastic stresses and strains was carried out. Elastic-plastic finite element (FE) analysis was used for the determination of rolling contact stresses. The implementation of a robust cyclic plasticity theory ensures an accurate stress analysis. In the current investigation, 1070 steel, a material often used for rails and wheels, was studied under two-dimensional rolling contact. The repeated rolling contact process was implemented with the translation of the normal pressure and the tangential traction across the contact surface, which were applied to the nodes through the time-dependant amplitude functions. The node force amplitude function was calculated by the Gauss integration before the FE simulation. With the detailed stress-strain response outputted from the FE stress analysis, a general multiaxial fatigue criterion was used to predict fatigue damage, crack initiation position and crack growth direction under rolling contact.Simulations were conducted under different normalized tangential tractionξ(ξ=Q/fp, where p is the normal pressure and Q is the tangential force, f is the coefficient of friction). It was found that cracks are predicted to initiate on the contact surface, and for the full slip (ξ=±1) fatigue crack is predicted to form subsurface at a depth of approximately 0.4a (where a is the half width of the contact region). The normalized tangential tractionξhas a very significant influence on the fatigue life.The approach developed in this paper is useful for the prediction of fatigue damage, crack initiation position and crack growth direction under rolling contact.
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