Initiation and Propagation Mechanisms of Rolling Contact Fatigue in High-Speed Railway Rails: A Review

Rolling contact fatigue (RCF) is a critical rail failure mechanism in high-speed railway (HSR) systems, caused by repeated wheel-rail contact under high Hertz stress, tangential forces, and complex multiaxial stress states.This study provides a systematic overview of RCF crack initiation and propagation in HSR rails.It first summarizes typical RCF failure modes and analyzes two crack initiation mechanisms.Subsequent propagation stages are examined, including short and long crack growth, mixed failure mechanisms, crack branching, and environmental influences.The study then evaluates existing predictive methods for RCF initiation and development.Current challenges and future trends are identified, particularly regarding short-term fracture behavior, multiphysical linkages, lifespan prediction, and field monitoring data integration.By synthesizing these key aspects, RCF in HSR is framed as a continuous, multistage failure process.Advancing integrated multi-level and multi-physical data approaches will be essential for improving prediction reliability and railway maintenance strategies.