Analysis Of The Influence Of Passenger And Freight Railway Curve Parameters On Rail Profile Evolution

The railway plays an extremely important and irreplaceable role in the development of the modern society and economy.Before the emergence of high-speed railways,the passenger and freight lines have always been the main line type of the world’s railways.The passenger and freight lines have serious rail wear due to the obvious difference in the speed,dynamic performance and axle load between passenger and freight trains.With the increase of train speed and axle load,the parameters of the curve section must be set scientifically and reasonably in order to ensure the safe and stable operation of the train and the normal service of the track structure.Based on the summarization of domestic and foreign scholars’ research,the paper establishes dynamic models of passenger and freight trains,then introduces the Specht wear calculation model to establish a prediction model for the evolution of rail profile.Taking into account the combined effects of different vehicle types and speed weights and using the small radius curve of a certain section of South Tongpu Railway downline as a prototype,the relationship between the parameters of the curve section in the passenger and freight lines and the evolution of the rail profile was further studied by the method of simulation analysis.The conclusions are as follows:(1)The wear of rails in the curve section is more serious than the tangent rail and transition section of the passenger and freight lines;The side wears of high rail is obvious and concentrated on the inner side of the rail head and rail shoulders.The degree of wear in the low rail is relatively light and mainly distributed in the middle of the rail head.The difference between the wear conditions of the left and right rails in the tangent section is slight and mainly distributed in the middle of the rail head.(2)A certain amount of cant deficiency in the curve section can inhibit the evolution of the rail profile,but it will result in a reduction in the smoothness and comfort of the passenger car;if the line conditions permit,increasing the radius of the curve to 800m or more has obvious effect on the safety of trains and suppressing the evolution of rail profile;If the length of the transition curve is increased to 90m or more,the evolution of rail profile in the small radius curve section has been suppressed to a certain extent;the influence of the length of the circular curve on the safety of the train and the rail profile is negligible.(3)Taking the 400m small-radius curve as an example to calculate,when using the triangular probability distribution for the speed distribution of the train negotiating the curve,the maximum wear depth of the high and low rail will decrease to a certain extent;And when the skewness of speed distribution is positive(ie,the distribution is biased towards lower speed),the suppression effect on the rail wear is more obvious;when the skewness of speed distribution is negative(ie,the distribution is biased towards higher speed),the suppression effect is no longer obvious,based on the calculation results,this paper suggests that a triangular velocity distribution with a skewness of 0.57 can be used when the train passes a 400m small radius curve,which can relieve the development of rail wear in the curved section to some extent.