Study on the vibration phase-locking mechanism and continuous excitation mechanism in the basic theoretical framework of rail corrugation

Rail corrugation is now a prevalent, hard-to-solve issue affecting nearly all metro lines across the globe. To achieve a comprehensive understanding of the mechanism underlying rail corrugation, one needs to examine why predictions derived from traditional corrugation theories diverge markedly from real-world observations of the phenomenon. This paper first outlines the prediction approaches and core conclusions of traditional rail corrugation theories, and then elaborates on the notable discrepancies between theoretical predictions and the practical occurrence rate of rail corrugation in actual railway operations. On-site rail vibrations were measured and analyzed. The results reveal that as trains pass, the rails are always continuously excited to vibrate at 20–1000 Hz; however, only a small portion of these vibrations induce rail corrugation. The authors propose a vibration phase-locking mechanism to account for the generation of rail corrugation. On-site investigations also indicate that the extent of rail corrugation on inspected tracks is usually patchy on large-radius curves or straight tracks, while it develops rapidly and spreads across the entire length of the curved section on tight curves. The authors put forward a continuous excitation mechanism to account for the progression of rail corrugation.