Rolling contact fatigue of railway wheels - a parametric study

With the increase of speeds and axle-loads in railway transportation, the fatigue life of the wheels has become an important issue with respect to economy and safety. A deeper understanding of the fatigue mechanisms and a better prediction of lifetimes should be of interest to both manufacturers and operators. In this paper, a refined equivalent-stress criterion is developed and is implemented in a previously described fatigue life model (A. Ekberg, H. Bjarnebed and R. Lunden, A fatigue life model for general rolling contact with application to wheel/rail damage, Fatigue Fract. Eng. Mater. Struct. 18 (10) (1995) 1189-1199). The influence of some important parameters on the fatigue life is evaluated using the improved model. The parameters varied are vertical wheel load, diameter of wheel, radius of railhead, residual stresses, and longitudinal and transverse contact stresses. The validity of the model and the consequences of the results are discussed. Finally, the possibility of using simplified equivalent-stress criteria in order to decrease the required computational efforts is discussed. (C) 1997 Elsevier Science S.A.