Influence of Vertical Elasticity of Carbody of Railway Passenger Vehicles on Ride Quality

A vertical dynamic model of railway passenger vehicles is built,which covers effects of carbody flexibility and all vertical rigid modes.With this model and the fast calculation algorithm of ride quality of railway vehicles,the influence of carbody flexibility on ride quality is researched.The results show that when the carbody flexibility decreases to certain frequencies the carbody will vibrate greatly.The higher the running speed of the vehicle,the higher the carbody stiffness required.The proposed method can readily obtain the lowest vertical first-order bending frequency required by ride quality.The example of a fully equipped high speed passenger vehicle in this paper shows that when the first order bending frequency is higher than 10 Hz,the carbody flexibility almost have no effect on ride quality.The results also show that if the carbody flexibility is rather low,enhancing structure damping and raising the primary vertical damping coefficient can help attenuate the flexible vibration of the vehicle.