Prediction Of Rail Wear In Curve Of Mixed Passenger And Freight Railway

With the improvement of the living standards of the people,in order to meet people’s material needs and facilitate people’s travel,railway transportation,as a mainstream transportation mode,has attracted widespread attention at home and abroad due to its large volume and high efficiency.China has successively opened Beijing-Guangzhou high-speed railway,Beijing-Shanghai highspeed railway,Shuohuang and Daqin heavy-duty railways.With the increase of the train’s total weight and driving frequency,the rail wear behavior becomes more and more prominent.In some small-radius curve sections where passenger and freight are mixed,the situation is more complicated,and the rail side wear is more serious.This not only brings serious damage to the vehicle.The hidden dangers also increase the cost of railway transportation and seriously damage the economic benefits of railway transportation.Therefore,this paper studies the influence of rail wear evolution on vehicle dynamics and the main factors that affect rail wear.This paper first introduces the research status of rail wear and rolling contact fatigue at home and abroad,and establishes dynamic models of freight cars,passenger cars and locomotives through SIMPACK dynamics software.A systematic analysis of the wheel-rail rolling contact theory is carried out,and the differences between various rail wear models are compared.A rail wear simulation program is written in MATLAB,and rail wear simulation is carried out jointly with SIMPACK.The article introduces the wheel-rail contact form and the distribution characteristics of the rail surface wear under various contact forms.The randomly selected wheels are classified according to the wheel rim height,rim thickness,and q R value.The representative wheels of the rail wear calculation and determine their proportions.The rail wear simulation program and the representative wheels are used to calculate the wear of a measured line.By comparing the simulation results with the measured data,the wear model was revised to enable it to effectively simulate domestic rail wear.This paper analyzes the influence of rail wear evolution on vehicle dynamic performance,and analyzes the coupling relationship between rolling contact fatigue and wear.The calculation results show that the wheel-rail vertical force,wheel load reduction ratio,and overturning coefficient are less affected by rail wear,while the wheel-rail lateral force,wheel axle lateral force,wheelset traverse amount,and wheelset angle follow the curve.The increase of the side wear of the rail gradually increases,which also causes the derailment coefficient and the side wear rate of the rails on the curve to continuously increase when the vehicle passes through the curve;during the evolution of the wear of the rail,the shoulders of the rails on the curve are most likely to be damaged.In the initial curve of rail wear,rolling contact fatigue and abrasion coexist on the shoulders of the rails,and fatigue cracks and peeling off are prone to occur at the shoulders of the rails.As the wear evolves,the wear rate gradually increases,and the wear on the rail surface is dominant.Under the curve,the wear of the stranded rails is uniformly distributed at the top of the rails,and expands to both sides as the wear evolves,but the wear rate changes little.Finally,the factors affecting rail wear were studied by wear calculation.The calculation results show that the change of the track superelevation has a small effect on the rail wear distribution.The rail wear increases with the increase of the track superelevation.Taking the rail bottom slope1/20 is beneficial to alleviate rail side wear.The 60 N steel rail is more resistant to side abrasion than 60kg/m rail,but its rail top wear is larger.The size and distribution range of rail wear decreases with the increase of the curve radius.The amount of rail wear decreases sharply when the curve radius changes from 300 m to 600 m.When the curve radius exceeds 60 m,the wear amount changes gently with the increase of the curve radius.At the equilibrium speed,the rail wear rate increases with the increase of the running speed.When lubricating the side of the rail on the curve,the friction after lubrication A coefficient of about 0.1 can effectively reduce the side wear of the rail.With the increase of traction,the longitudinal creep force gradually increases,and the lateral creep force,wheel-rail lateral force,and wheel pair traverse amount gradually decrease,causing the wheel-rail contact points to converge toward the center of the rail head,reducing the wheel The side of the steel rail is worn,but the concentration of wheelrail contact points results in increased rail wear.