Carbody abnormal lateral vibration failure of high–speed train induced by the coupling factor of the wheel re–profiling method and excessive rail wear

Low–frequency carbody swaying, a common abnormal lateral vibration failure during the commercial operation of high–speed trains, could seriously deteriorate passengers' ride comfort. Certain high–speed trains were detected to suffer from abnormal carbody vibration on certain railway lines, apart from which there were no abnormal vibrations detected. Investigation and analysis of this unusual failure were conducted. Wheel rail profiles of the operating trains and the commercial railway lines were measured and analyzed. Excessive low equivalent conicity leads to instability of carbody hunting, which contributes to carbody swaying. The coupling factor of the wheel re–profiling method and excessive rail wear cause the excessively low equivalent conicity. Linear and nonlinear numerical simulations on the mechanism of instability were carried out. Countermeasures of the new wheel re–profiling method and grinding the rail to the new profile were proposed and validated in the field test. A critical rail profile was also proposed for evaluating whether to grind the rail, which was proved to be effective by the daily operation response. The results of this study could enrich the knowledge of carbody swaying and provide a reference for solving it.