Wheel-rail Wear Prediction And Dynamic Performance Analysis Of Metro Vehicles Based On UM

With the rapid development of urban rail transit in China,subway,as a large capacity rapid passenger transport system,plays an important role in urban rail transit.The characteristics of subway vehicle operation,such as more proportion of small radius curve,normal overload operation and frequent acceleration and deceleration,further aggravate wheel-rail wear.The aggravation of wheel-rail wear will cause noise and severe vibration of the vehicle track,which will affect the safety,stability,smoothness and ride comfort of the subway vehicle operation.The bad condition will lead to the derailment of the vehicle,which will harm the personal and property safety of the passengers.It is particularly important to study the prediction of wheelrail wear of subway vehicles and analyze the influence of wheel-rail wear on the dynamic performance of subway vehicles to ensure the safety and reliability of subway operation.In this paper,the research status of wheel-rail wear prediction by domestic and foreign scholars is discussed in detail,the background significance and purpose of the research on wheel-rail wear prediction are clarified,and the overall research ideas and main research contents of this paper are summarized.The basic structure and design characteristics of the ZMC120 bogie of A-type metro vehicle are introduced.According to the parameters of A-type metro vehicle,the corresponding vehicle dynamics simulation model is established in UM multi-body dynamics software.According to the actual running line and subway design specification,the line model based on the actual line is established,and the incentive of track irregularity is added.The wheel-rail rolling contact theory and related algorithms,as well as the commonly used material wear models are introduced.Use UM dynamics simulation of multi-body dynamics simulation software,to get the parameters of the combined with non Hertz contact based on virtual penetration Kik-Piotrowski method and the Archard wear model,calculated the variation of wheel type,from the initial wheel type surface to remove these variation and smoothing can be after the abrasion of wheel profile,multiple loop calculation of wheel type surface abrasion prediction.Based on metro vehicle system dynamics model,the wheel/rail rolling contact model and material abrasion wheel/rail wear prediction model is established and the abrasion prediction simulation,100000 kilometers of wheel wear is obtained under different running mileage: are abrasion wheel tread and flange,and flange abrasion quantity significantly greater than the tread wear volumes;The wear range is mainly distributed between-40 mm ～ 40 mm,and the wheel wear range is basically the same under different operating mileage,and the wheel wear shape is basically similar.Wheel wear depth increases linearly with the increase of running mileage.Under different degree of wheel/rail wear and analyzes the change rule of wheel/rail contact geometry parameters: different stages of abrasion of equivalent taper is broadly in line with a change rule and the difference is small,round about to speed across less than 5mm equivalent taper is greater than the standard wheel-rail wear of wheel-rail match,and wheel speed across the opposite was greater than 5mm;Different stages of abrasion wheel/rail contact Angle change law is broadly consistent,when the wheel to move to the left when the wheel speed across-8mm ～-4mm range,increase with the increase of the wheel/rail contact Angle with the running miles,when the wheel speed across-4mm ～ 0mm range,wheel/rail contact Angle decreases slightly with the increase of running mileage,and when the wheel to the right of change is not obvious,but the wear of wheel/rail matching wheel/rail contact Angle slightly smaller than the standard wheel/rail matching.The influence of wheel-rail wear on the dynamic performance of subway vehicles is analyzed from three aspects,namely,the stability,the stability and the safety of the vehicle running through the curve,from two perspectives of the performance of straight line running and the performance of curve passing.The results show that the wheel-rail wear reduces the running stability of subway vehicles,and the critical velocity of serpent instability decreases,but the wheel-rail wear has almost no effect on the running stability of subway vehicles.Under the same operating speed,the derailment coefficient of the outer rail is larger than that of the inner rail on the whole.The maximum derailment coefficient of the outer rail is less than 0.8,which meets the good standard,and the maximum derailment coefficient of the inner rail is less than 0.6,which meets the excellent standard.Wheel-rail wear has a fluctuating influence on the wheel-rail lateral force.The wheel-rail lateral force on the outer rail is much larger than that on the inner rail,and the maximum wheel-rail lateral force is less than 37 k N,which is within the safety limit.Wheel-rail wear has almost no effect on the wheel weight reduction rate.At the same running speed,the maximum wheel weight reduction rate of the 1-position wheelset of the front bogie is larger than that of the 2-position wheelset.