Research on abnormal vibration of high-speed train based on wheel-rail coupling modal analysis

Abstract

During dynamic line testing of a high-speed train, it was observed that the vehicle exhibited significant abnormal vertical vibrations under specific track conditions. The frequency of this vibration varies with the train speed and exhibits harmonics through analysis. As the speed approaches 400 km/h, the peak frequency is close to 44 Hz, corresponding to the system structure's natural frequency. A finite element model of the wheel-rail coupling was established for modal analysis, which revealed that the coupling between the bogie and the track will form a bogie P2 force resonance mode, which closely matches the frequency range of the abnormal vibrations. A dynamic model of vehicle-track rigid-flexible coupling was established, to simulate vibration reproduction and the bogie P2 force resonance mode variation law. Additionally, irregularities of specific wavelengths on the track can excite this mode, leading to a significant increase in amplitude. Some sections of the track line have slab warping, with a wavelength of approximately 2.45m. The frequency range of excitation formed when the vehicle speed approaches 400 km/h is close to that of the bogie P2 resonance mode. As a result, coupling resonance occurs between the vehicle and track systems, ultimately causing abnormal vibrations.