A Way for Vibration Analysis of High-Speed Train

In the wake of the large-scale application of high-speed railways in China, the China Railway high-speed (CRH) trains are running at full capacity with the increase of operating speed and diversified service conditions. The complex vibrations have been causing new situations in operation safety and maintenance more often. In the vibration detection and maintenance of train components, some abnormal vibrations were often detected. Using the forced vibration theory for analyzing these detection data, it is impossible to explore the source and mechanism sometimes. In order to find out the source and mechanism of this part of vibration, a new way to analyze the vibration of high-speed trains is proposed in this paper. The theory of self-excited vibration is used to explore the vibration mechanism of train wheel-set under the change of wheel-rail adhesion, and a simplified torsional vibration model based on traction system is established firstly. The model's negative damping characteristics and frequency response due to speed feedback are analyzed. Then, the self-excited vibration condition is simulated via a CRH train dynamic model under the Wuhan-Guangzhou track spectrum, and the frequency response is analyzed when self-excited vibration occurs. The simulation results show that the self-excited vibration is generated under some conditions of the train operation, and the main frequency of the vibration is coupled with the natural frequency of the components to generate resonance, which can intensify the vibration of the components and result in abnormal vibrations. The new way to analyze vibration can provide theoretical basis and technical support for the operation safety and maintenance of high-speed trains.