Research on Rolling Contact Fatigue Life and Damage of Rail Materials

Abstract

During long-term service of trains, the fatigue and damage of material caused by wheel/rail contact are becoming increasingly severe. In this article, the numerical calculation and fatigue experiment are used to study the fatigue damage of rail material. Firstly, a three-dimensional calculation model for fatigue contact of rail material is established to obtain fatigue parameters during rolling contact. Secondly, the fatigue parameters in the process of rolling contact are obtained, and then the fatigue life of rail material is calculated based on Jiang’s fatigue damage theory. Finally, the twin-disc rolling fatigue experiments are conducted according to the limit pass number, and the fatigue damage characteristics of rail material are researched. The results show the maximum Mises stress in the contact area is 576 MPa, the shape of contact area is approximately elliptical, the contact area is 0.82 mm², and the limit pass number of rail material is 7.73 × 10⁶. The peeling and pitting are very significant on the specimen surface. In the longitudinal section, cracks appear along the direction of plastic flow line. A large number of fatigue cracks can be found on the subsurface of transverse section.