Research on Vibration Control and Nonlinear Dynamic Behavior of Railway Vehicle Systems Based on Nonlinear Energy Sinks

During large-scale operation, railway vehicles are prone to issues such as abnormal vibrations in the car body or bogie frames. To simultaneously reduce vibrations in both the car body and the bogie frames, this paper proposes the distributed installation of nonlinear energy sinks (NES) on railway vehicles, specifically by mounting multiple NES units on the car body and bogie frames. First, a nine degrees of freedom coupled dynamic model based on the rail vehicle and NES is built. The approximate analytical solution of the model is obtained using the harmonic balance method, and it is verified with numerical solutions. The effects of the mass, cubic stiffness, and damping of the NES on the amplitude-frequency response curves of the car body and bogie frames are analyzed. Finally, the influence of the mass, cubic stiffness, and damping of the NES on the nonlinear dynamic behavior of the model is researched. The influence of parameters in NES on the system response is studied from multiple perspectives, including the time history curve, phase trajectory and Poincaré map. The research results indicate that the distributed installation of NES units can effectively suppress vibrations of the car body and bogie frames. Moreover, by appropriately designing the mass, damping, and cubic stiffness parameters of each NES, the vibrations of the car body and bogie frames can be further reduced, while avoiding adverse effects caused by chaotic and bifurcation responses in the system. The study provides the guidance for the parameter design of NES and offers foundational theoretical support for their broader application, which holds positive significance for mitigating vibrations in railway vehicles.