Mathematical Modeling and Simulation of Suspended Equipment Impact on Car Body Modes

A passenger railway vehicle’s lightweight design is an efficient technique of reducing energy consumption and dynamic forces between wheel and rail. However, light design results in resonant vibration in a car body. To restrain resonant vibration, a correlation between the suspended equipment variables and the car body’s modal frequency was investigated in this paper. A rigid–flexible general model was developed to examine the impacts of different equipment suspended under the chassis based on mass, location, and frequency on the car body mode. In addition, the numerical model is validated through the experimental result in terms of ride quality. The results demonstrate that the underframe equipment’s suspension characteristics have a significant impact on the mode of the car body, particularly the frequency of the first bending mode. Equipment with a considerable mass should be suspended near the center of the car body to optimize the frequency of the car body’s high-frequency bending. The weight of the equipment has a significant impact on the car body’s first bending frequency. The frequency of heavy equipment should be low enough to promote high-frequency transmissibility and improve the vibration characteristics of the car body.