Study on the Mechanism of the Influence of Passenger Load on the Vibration Characteristics of Railway Vehicles Based on Modal Characteristics

In order to investigate the effect of passenger load on the vibration of rail vehicles, a modal experiment was conducted on a certain type of high-speed train under empty-load, rice counterweight, and passenger-carrying conditions. The influence of different load configurations on the modal vibration of the vehicle was examined and analyzed using multi-point excitation and sine sweep frequency methods. The differences between the impact of passenger and rice loads on vehicle vibration were elucidated. Subsequently, the human–vehicle coupling mathematical model was modified based on the experimental results, and the differences in the effect of different loads on vehicle vibrations were simulated and analyzed. Finally, the attenuation mechanism of passenger loads on vehicle vibration was analyzed. The research has established that the modal parameters of the vehicle are greatly influenced by different loads. Numerical calculations demonstrate that the vertical bending mode of the car body in the middle experiences a maximum vibration attenuation of 60% when carrying passengers compared to the same mass of mass loaded. The natural frequencies and damping ratio of passengers can significantly affect the vertical bending mode vibration. The findings of this research can serve as a theoretical foundation and technical assistance for implementing vehicle vibration reduction techniques.