Study On Coupling Vibration Of High-Speed Emu Between Carbody And Underframe Equipment

Lightweight design of carbody makes aluminum alloy profiled materials widely used in the high-speed carbody, but lightweight design generally decreases the carbody structural stiffness and the carbody will has serious vibration. At present, the equipment mostly is suspended under the carbody. The design approaches will inevitably influence on the vertical bending stiffness of carbody and greatly reduce the vertical bending frequency of carbody. In order to reduce the influence of equipment on carbody bend frequency, a simple way is to introduce elastic suspension. However, if suspension parameters do not match with carbody structure, there are significant vibrations in carbody. This paper focuses on the coupled vibration problem between carbody and equipment, based on rigid-flexible coupling dynamic and studies interaction between carbody and equipment, using the method of combining simulation and experiments.(1) This paper gives a detailed description on the method, modeling two-dimensional and three-dimensional coupling model of carbody and equipment under car.(2) This paper has a detailed analysis of carbody oneself vibration characteristics and the random vibration response, using vertical coupling system model of carbody and equipment, including elastic vibration effect of carbody.(3) The simulation with rigid-flexible coupling dynamic model is compared with rolling rig test and on-line test. The result show that the rigid-flexible coupling model can simulation the vertical vibration characteristics of carbody and has better consistency with rolling rig test and on-line test.(4) The differences between traditional rigid dynamic model and rigid-flexible coupling model have been studied and defined usable range of them.(5) The influence of equipment on vehicle dynamic performance is studied based on rigid-flexible coupling dynamic theory. The difference between rigid suspension and flexible suspension on ride quality and safety are analyzed. The feasibility and necessity are validated to apply flexible suspension. By analyzing influence on the dynamic performance of vehicle of different equipment layouts, the engineering design principles are carried out. At the same time, the different influence laws of different equipments on carbody vibration are studied and the results provide a certain theoretical reference for the design of the suspension system of equipment under vehicle.(6) This paper studies the different influence law on fatigue life of suspension components between rigid suspension design and flexible suspension design.