Investigation On Safety Stability Margin Control Of High-Speed Railway Vehicles

The vibration alarming trouble is a special phenomenon of the Wuhan-Guangzhouhigh-speed rail, and it show that the wheel-rail wear is a very sensitive affect on high-speedbogie stability margin. Combination of vibration alarm test survey and analysis, a dynamicsimulation analysis based on model was done in this paper. It pointed out that the smallhunting oscillation formed by the local concave wear tread is one of the main causes of thealarm failure.Because of wheel-rail contact hunting oscillation is no longer inherent in the same. Theenergy absorption band of anti-hunting damper mode must be used in order to improve thebogie stability margin. The CRH3C bogie stability margin is not very abundant，the test showthat in the wheel-rail local tight contact, the small hunting oscillation excitation made theframe lateral resonance. It’s frequency up to6.4Hz, and cause the yaw damper unloading. Asthe hysteresis nonlinearity of trailer frame pitching, once the anti-hunting blow-off, thetrailer’s frame will have a lateral flutter, and alarm. Also, because the anti-hunting damperdissipation capacity constraints, this will, such as unloading caused by the transverseresonance;the oil spill phenomenon by lateral impact generated, called as the high-frequencyunloading mechanism. The nonlinear effects refer to the anti-hunting damper t nonlineardynamic stiffness due to the high-frequency unloading mechanism. Therefore, small huntingsafety theory is no longer applicable with the nonlinear behavior of high-speed bogie.Through this work can be two reasons for the Wuhan-Guangzhou alarm:First, the external cause：because of the tread partial concave abrasion make therelationship deterioration between wheel-rail contact,it formation the small hunting and causethe high-frequency excitation;Second internal cause: the hysteresis nonlinearity of trailer frame pitching form10~30Hz wideband response in the vertical, once the unloading, and the trailer frame will appearlateral flutter or sustained high-frequency vibration, and cause vibration alarm.According to the anti-hunting series stiffness affect to the spectrum of the energyabsorption characteristics, the anti-hunting soft constraints control technologycountermeasures proposed. In small displacement perturbation conditions, make the yawdamper hypothetical model, that the hydraulic stiffness is high, anti-hunting series stiffness ishalf of the rubber stiffness of the end nodes. If the anti-hunting series stiffness doubling, andthe safety assessments of the nonlinear behavior that based on dynamic simulation show that：the stability margin of CRH3C bogie is improved, such as critical speeds and the commercialspeeds have been significantly improved. Above adjustment must be achieved by replace the rubber nodes, which will be referred to as anti-hunting soft constraints. The simulationprospective results show that the350~380km/h HSR safety operation can be guaranteed bythis anti-hunting soft-constraint strategy. And this anti-hunting soft constraints control hasbeen verified in the process of resolving high-speed Shaking.