Material defects in rolling contact fatigue of railway wheels-the influence of defect size

The influence of the size of material defects on rolling contact fatigue of railway wheels is investigated. To study differences between uniaxial tensile loading and rolling contact loading, finite element simulations of a defected component are carried out. The results show that stress and strain fields (as quantified by the Jiang-Sehitouglu multiaxial fatigue criterion) in the vicinity of a defect differ between these two cases. It is concluded that semi-empirical methods derived for uniaxial loading are doubtful for rolling contact applications. Instead, an elasto-plastic finite element based model is designed and employed to compare fatigue impact of defects of different sizes subjected to rolling contact loading.