Grinding limit and profile optimization in the high-incidence section of rail corrugation in mountainous city metro

As the most common and direct control method for rail corrugation, the rail grinding can effectively improve the service life of rails, but requires scientific theoretical guidance to achieve the efficient grinding. Therefore, it is necessary to formulate corresponding grinding limits and profile optimizations for different characteristics of rail corrugations. According to the on-site investigation of rail corrugation in the overlapping section of horizontal-vertical curves of the mountainous city metro, the corresponding dynamic model of vehicle-track system is constructed. Through the safety evaluation of the dynamic characteristics of the vehicle-track system, the safety limit of the rail corrugation grinding is preliminarily determined. Then, based on the wheel-rail friction-coupled vibration theory, the finite element model of the wheel-rail system is built. By exploring the wheel-rail friction-coupled vibration characteristics in the corrugated section with typical characteristics, the optimal limit of rail corrugation grinding is further confirmed. Finally, the treatment effects before and after rail grinding are compared using the profile optimization. Results show that when the corrugation wavelengths in the overlapping section are 30 mm, 40 mm, 50 mm, 60 mm, and 70 mm, the safety limits for rail corrugation grinding are 0.03 mm, 0.04 mm, 0.05 mm, 0.08 mm, and 0.15 mm. For the typical rail corrugation with the wavelength of 50 mm, the optimal limit of the rail corrugation grinding is 0.02 mm. Moreover, the earlier the rail corrugation is polished, the better the relative optimization effect is, but it is necessary to consider the grinding cost for targeted grinding.