Influence of equipment under car on carbody vibration

In order to consider the elastic vibration of carbody, the vertical coupling vibration model of carbody and equipment was established, the influence of rigid suspension and flexible suspension on the amplitude-frequency characteristic of carbody was studied, in which carbody was modeled as an Euler-Bernoulli beam. The 3D rigid-flexible coupling dynamics model of high-speed EMU was set up based on the modal superposition method and considering carbody elastic vibration and equipment, the influence of equipment's suspension types, partial loads and suspension parameters on carbody vibration was andyzed. The numerical analysis result of Euler-Bernoulli beam model shows that reasonable elastic suspension design based on the principle of dynamic vibration absorber can effectively suppress the elastic vibration of carbody and improve the vertical bend frequency of carbody. The simulation result of 3D rigid-flexible coupling dynamics model shows that the higher the speed is, the more obvious the advantage of elastic suspension is, equipment's lateral partial load affects the lateral riding index of carbody, and the longitudinal partial load mainly affects the vertical riding index. When the flexible suspension frequency of equipment is close to carbody bend frequency, the minimum vibration of carbody occurs. But as the suspension frequency of equipment is less than carbody bend frequency, rising damping can suppress carbody vibration to some extent.