Study on Vertical Coupling Vibration Law of Metro Vehicle Based on Flexible Carbody

Abstract

Objective With the increase in train operating speed and the adoption of lightweight design, the dynamic forces between the wheel-rail interface are intensified, leading to exacerbated vibrations among various components of the vehicle. This significantly affects the vehicle dynamics performance, necessitating research on vertical coupling vibration law between bogie and flexible carbody. Method Taking a certain model of metro train as the research subject, a rigid-flexible coupling model including a flexible carbody is established. The vertical vibration coupling relationship between the carbody structure mode and the bogie suspension mode is studied using the steadiness index of relevant measuring points. Result & Conclusion The results indicate that, when the bogie floating and nodding frequencies are close to the first-order bending frequency of the carbody, considering only the first-order vertical bending mode of carbody can induce a coupling resonance phenomenon between the flexible body and the bogie, with the central measuring point being the most affected. When considering only the rhomboid deformation mode and first-order torsional mode of the carbody, coupling resonance between bogie and flexible carbody will not occur, but both are influenced by track excitation resonance effect. When considering the carbody combined structure mode, the central measuring point of the carbody is most affected by the first-order vertical bending mode, leading to a coupled resonance phenomenon between the flexible carbody and the bogie. On the other hand, the carbody measuring points above the bogie are prone to be affected by first-order torsional mode, resulting in modal resonance effects at some speed levels.

Keywords

• metro vehicle
• rigid-flexible coupling
• vertical coupling vibration
• operation stability
• first-order vertical bending