Dynamic optimization of the rail-crown geometry in the rigid frog area by controlling the position of the wheel-load transition

Abstract

To improve the stability of a train and reduce its influence on the nose rail when passing a rigid frog, the optimization of the rail-crown geometry in the rigid frog area is proposed in this study by controlling the transition range of the wheel load on the nose-rail head and evaluating it by a wheel–rail dynamic coupling model. The method was verified by studying a Chinese CN60-350-1:12 turnout. Results show that if the wing-rail heightening and nose-rail reduction are small, then the transition section of the wheel load on the nose rail may be close to or smaller than the minimum load-bearing cross section, which will cause damage to the weaker section of the front of the nose rail due to excessive load. If the wing-rail heightening and nose-rail reduction are large, the wheel-load transition section of the nose rail may exceed the extreme transition cross section, which will cause the wheel to hit the nose-rail head or make it difficult to climb the wing rail when the wheel passes through the rigid frog. During the optimization process of the rail-crown geometry in the rigid frog, the reasonable transition range of the nose-rail head can be determined by adjusting the wing-rail heightening and nose-rail reduction, and combined with the wheel–rail dynamics evaluation method, the optimal scheme can be selected to protect the nose rail and improve the running stability of the train.