Research On Polygon Limit Of High Speed Train Wheel

With the continuous optimization and development of high-speed trains,their speed has been greatly improved,which intensified wheel-rail vibration,resulting in wheel polygons and rail corrugation that are widespread in the operation site,and deteriorating vehicle dynamics.At present,most of the literature still studies the wheel-rail dynamic response under a single wear excitation.In train operation,wheel polygon and rail wave wear are more common on trains and tracks.Research on the dynamic response of trains caused by such phenomena is still insufficient.This article focuses on the impact of these two types of wear on the safety characteristics of trains.According to the main parameters of a certain type of high-speed train in China,the corresponding high-speed train rigid-flexible coupling dynamics model is created;the wheel polygon and rail corrugation are expressed in the form of harmonic function and cosine function respectively,and the measured data are compared and verified.Co-simulation to study the train dynamic response caused by the wheel polygon,rail corrugation,and the combined wear of both polygon and corrugation,and follow the limit of 170 k N wheel-rail vertical force in the International Railway Union UIC-518 as the standard.Put forward safety limits on wheel polygons,and provide technical support for wheel operation and maintenance.The simulation analyzes the dynamic performance changes of the vehicle system caused by different speeds,wheel polygon orders,amplitudes,and different rail corrugation wavelengths and wave depths,wheel polygons,rail corrugations,and the combined wear of the two.The results show:(1)Under the abrasion of the wheel polygon,when the speed,order and amplitude are increased,the wheel derailment coefficient,wheel load reduction rate and wheel-rail vertical force will increase accordingly.At this time,the axle box,wheel set and rail The vertical vibration acceleration also tends to increase.At different speed levels,when the speed is increased to 300km/h and the polygon order is 20,the maximum increase in the maximum wheel-rail vertical force corresponding to the wheel-rail vertical force increases by 30.7%.The corresponding vibration frequency is 576.1Hz and the wheelset The modal calculation of the 25 th mode of 580.8Hz is closer,that is,the wheel resonates with the 25 th mode of mode,resulting in increased vibration and shock.At the same time,the increase in the maximum vertical vibration acceleration of the axle box,wheelset and rail is similar to that of the wheel-rail sag.Xiangli performed the same,with the largest increase.Among them,the increase in the vertical vibration acceleration of the axle box and wheelset is significantly greater than the vertical vibration acceleration of the steel rail,that is,when the train has polygonal wear,the vibration of the components on the vehicle rail will be more affected;(2)Under the excitation of rail wave wear and abrasion,when the wave depth is increased,the wheel derailment coefficient,wheel load reduction rate and wheel-rail vertical force increase correspondingly.At this time,the vertical vibration acceleration of the axle box,wheel set and rail It also has an increasing trend;but as the wavelength decreases,the wheel derailment coefficient,wheel load reduction rate,and wheel-rail vertical force will also increase.At the same time,the corresponding vertical force of the axle box,wheel set and rail of the train will increase.The amplitude of vibration acceleration has also increased;when the train runs at different speeds,the increase in the maximum vertical vibration acceleration of the rail is significantly greater than the vertical vibration acceleration of the axle box and wheelset.Vibration under the rail has a greater impact;(3)The impact on the dynamic performance of the train under the comprehensive wheel-rail wear disturbance is obviously more severe than that under only the wheel polygon and only the rail wave abrasion.The safety limit of the corresponding wheel polygon under the comprehensive wheel-rail wear is lower than that under the single polygon wear condition.When the train is running at low speed,the corresponding polygon amplitude limits of the two are not much different.The vehicle speed exceeds 250km/h.Under the effect of comprehensive wheel-rail wear,the corresponding polygonal amplitude limit is significantly lower than that of only polygonal wear conditions,and it is easy to exceed the limit;when the speed is 300km/h,it is proposed that the rail corrugation wavelength is 120～160mm and the wave depth is at Within the range of 0.01～0.04 mm,the wheel polygon order 10～30corresponds to the safety limit of the wheel polygon within the amplitude range of 0.1mm.