Influence Of Metro Track Parameters On Wheel-Rail Abrasion

As an important part of urban rail transit,track provides a basis for the safe operation of rail transit.Reasonable track parameters can ensure good wheel-rail wear and running stability.In this paper,a metro vehicle model is established by UM simulation software,combining wear theory and vehicle coupling dynamics theory.The derailment coefficient and wheel load reduction rate are taken as safety evaluation indexes,and the wear area and maximum wear amount are taken as wheel-rail wear evaluation indexes.The effects of different values of three track parameters on rail and wheel wear are studied,including rail bottom slope,gauge and transition curve length.Simulation research.The main work is as follows:(1)To collect the wear data of rail and wheel on a metro line in a city.Master the wear characteristics of rails and wheels under different track parameters.The collected data show that the main wear modes of rail are lateral wear of curve outer rail and vertical wear of curve inner rail,while the main wear modes of wheel are tread and flange wear.At the same time,it provides reference data for the following simulation research.(2)Based on vehicle-track coupling dynamics and Archard material wear theory,a 12 t axle-load Metro vehicle-track model is established by using multi-body dynamics software UM.In order to ensure traffic safety,several commonly used traffic safety indicators are selected as the test object to ensure that the selection of parameters meets the requirements of safe driving.(3)The rail wear variation of three track parameters,namely rail bottom slope,gauge and transition curve length,under special conditions is simulated and studied,and the influence law of the change of relevant parameters on rail wear is obtained.(4)The wheel wear variation of three track parameters,i.e.rail bottom slope,gauge and transition curve length,is simulated under special conditions,and the influence law of the change of relevant parameters on wheel wear is obtained.The influence of the same parameters on the strength of wheel and rail is not the same.A compromise selection can make both parameters achieve the effect of reducing wear.Choosing a small rail bottom slope within the safety limit can better improve the wheel-rail relationship.When the bottom slope of 1/60 rail is selected,the wear of rail and wheel is the smallest at the same time.However,with the train running on the line,the rail bottom slope will gradually become smaller,so the rail bottom slope should be kept between 1/30 and 1/40 in the initial construction of new lines.When the gauge is in the range of-1-4 mm,the gauge is widened by 2.5 mm,which can make the effect of reducing the wear of rail and wheel at the same time the most reasonable.The longer the transition curve is,the smaller the wear of rail and wheel will be,but too long transition curve will increase the workload of operation and maintenance.When choosing the length of transition curve,many factors such as vehicle speed,superelevation and so on should be considered comprehensively.