Research On High Frequency Vibration Of Wheel-rail System And Its Influence On Axle Fatigue

With the rapid development of high-speed railway,the wheel wear of high-speed EMU vehicles and the rail wear of high-speed railway lines are becoming more and more serious.The high-frequency vibration of wheel rail system caused by the existence of wheel rail periodic wear not only affects the wheel rail contact relationship and worsens the operation quality,but also causes fatigue damage to vehicle components and endangers the safety of train operation.In order to explore the influence of wheel rail periodic wear on vehicle high-frequency vibration characteristics and axle fatigue damage,combined with the rigid flexible coupling dynamics theory,this paper establishes the rigid flexible coupling dynamics model of trailer track rail bottom structure of CR400 BF EMU,and analyzes the influence law of wheel rail periodic wear on wheel rail system highfrequency vibration characteristics and axle fatigue damage.The specific research is as follows:1.According to the dynamic parameters of CR400 BF EMU trailer,the rigid flexible coupling dynamic model of vehicle track bottom structure based on flexible track,flexible wheel set and flexible track bottom system is established,and the correctness of the model is verified based on the measured data.Then,the mathematical model of harmonic wheel rail short wave irregularity in the ideal state is established,and the model is imported for simulation calculation.2.Through simulation calculation,the influence rules of different wheel polygons and different rail wave wear conditions on the high-frequency vibration characteristics of CR400 BF EMU trailer such as wheel rail force,rail acceleration,axle box acceleration and fastener anti support force at different operating speeds are analyzed.Then the dynamic stress response and influence of axle under different working conditions are obtained.3.Through simulation calculation,the variation law of high frequency vibration characteristics of CR400 BF EMU Trailer under the coupling action of wheel rail periodic wear is analyzed.Then,the high-frequency vibration characteristics are compared with those of wheel polygon and rail wave wear.Finally,the time history of axle dynamic stress under coupling condition is obtained.4.Combined with miner’s linear cumulative damage theory and the modified S-N curve,the influence of wheel rail periodic wear on axle fatigue damage under different working conditions is studied.Finally,combined with the measured irregularity of Beijing-Shanghai line and the curve distribution of Beijing-Shanghai line,the axle damage value after passing through Beijing-Shanghai line when there are polygons is calculated,which lays a foundation for subsequent research.