Research On Turnout Contact Characteristics And Wear Law Of Thin-rim Wheels

The wheel-turnout relationship is an important issue in rail transit systems,and its unique structure makes the wheel-rail contact relationship significantly different from ordinary wheelrail contact.The high speed of the railway makes the problem of wheel and rail wear caused by vehicles running in turnout areas increasingly prominent.The wear caused by wheel-rail contact will seriously affect the dynamic performance of railway vehicles.In recent years,with the development of numerical methods and computers,the means of using simulation calculations to analyze related problems has become increasingly rich.This paper uses Matlab numerical tools,Abaqus finite element analysis tools,and Universal Mechanism multi-body dynamics analysis tools to analyze the contact and wear characteristics of turnout zones for vehicles with different wheel flange thicknesses.The main content of this article is as follows:For the calculation of the geometric relationship between the wheel flange and the rail of the thin rim,the calculation of the geometric relationship when passing the turnout is mainly considered.An appropriate range of the thickness of the wheel flanges of the train wheels is obtained according to the calculated geometrical relationship when the train passes the turnout to ensure that the train can safely pass the turnout.Considering the most severe conditions from the safety point of view,the thickness of the wheel rim is preferably greater than or equal to 26mm(25mm value plus 1mm margin).The multi-point contact calculation method of wheel-rail matching was programmed using Matlab numerical tools.The matching performance of the standard wheel and the rim-thinning wheel and the key section of the turnout area is compared and analyzed without considering the relative motion of the sharp rail(heart rail)and the basic rail.After the wheel rim of the vehicle is thinned,it has better matching performance.The matching area is also away from the gauge angle and the root area of the rim,and the matching area has a higher degree of fit.More fit matching has an important impact on improving the passing ability of the vehicle turnout area and reducing the wear.The finite element analysis software Abaqus was used to divide the wheel-rail contact area into a reasonable mesh size,and the calculation method was reasonably selected according to the characteristics of implicit calculation and explicit calculation.The contact stress and contact spot distribution of the key section between the wheel and the 18 th high-speed movable center rail turnout were calculated.The influence of the traverse amount on the contact state between the thinning wheel and the typical turnout section was analyzed,and the wear of the thinning wheel was analyzed Changes in contact state between the rear and typical turnout sections.After the vehicle wheel rim is thinned,the distribution of wheel contact points can be effectively controlled to reduce the contact stress distribution at the wheel rim.The finite element analysis tool Ansys is used to analyze the modal of the high-speed EMU tow wheel and transform it into a flexible body required by the dynamic model.After using multibody system dynamics software Universal Mechanism as a modeling and simulation platform to model the vehicle-turnout coupling model considering the flexibility of the wheelset,the passability of the vehicle turnout area was analyzed,and the wear characteristics of the turnout area of standard LMB wheels and thinned LMB wheels were analyzed.It can be seen from the comparison of turnout rail profile wear between standard wheel and thinning wheel after passing through 10 mt that the center rail wear is reduced after the passing of the thin wheel rim vehicle.