Prediction of Rail Rolling Contact Fatigue Crack Initiation Life via Three-Dimensional Finite Element Analysis

Rolling contact fatigue (RCF) is a common cause of rail failure due to repeated stresses at the wheel-rail contact. Untreated RCF defects can lead to many catastrophic outcomes. As preventative maintenance of rails is more cost effective than corrective maintenance, it is essential to comprehend the mechanism of RCF crack initiation. This paper, therefore, aims to design and develop a dynamic three-dimensional finite element model that can predict RCF crack initiation life and identify crack plane orientation. Axle box acceleration (ABA) signals from smooth and cracked rails were also simulated and analysed. Results show that the highest von Mises stress is located at 2.56 mm below the rail surface, where crack initiation takes place. With critical plane orientation at maximum fatigue parameter, the predicted RCF crack initiation life is about 832000 cycles, which corresponds to roughly 149 days for 5600 wheelset passages per day. Simulated ABA signals induced by RCF cracks exhibit high energy over a wide frequency range, with the strongest energy between 270 and 600 Hz.