Investigation On Adhesion Property Of Wheel/Rail

With the development of the world economy,high speed and heavy load railway are becoming the main developing direction of the rail and wheel.When the train is running,its traction and braking are provided by the tangential force between wheel and rail,which is wheel/rail adhesion.Nowadays,the most important task is to find the best adhesion point,control it and improve the force using rate of traction and braking.This paper used the theory of Carter’s two dimensional rolling contact and the rough surface steady partial elasto-hydrodynamic lubrication, studied the effect of speed,axle load and viscosity on adhesion force and film thickness applied numerical analysis mode under various conditions; numerical methods " CONTACT " on basis of the theory "Non-Hertz" rolling contact have been employed to analyse the effect of curve radius,travers and yaw angle on the contant area and the proportion of stick/slip area in contact area when trains are at static states as to two normally used tire tread (LM and TB) in China,getting results as follows:1. When under the same axle load,if the wheel rolling speed and viscosity get higher, the mean asperities contact pressure decrease and the mean hydrodynamic pressure increase,while the adhesion coefficient declines as the ratio of the mean asperities contact pressure to the total pressure becomes smaller,the mean central film thickness and minimum film thickness get bigger,this would improve the load capacity of the film.When the axle load gets weighter, the adhesion coefficient increases as the ratio of the mean asperities contact pressure to the total pressure becomes bigger and the mean central film thickness almost unchanged,while the mean minimum flim thickness decrease.2.It is indicated that in all working states the contact area of TB style is bigger than those of LM,as the curve radius increases,the contact area does not change,however adhesion coefficient increases as well as the stick proportion decrease;when the travers increase to10mm,the contact area decreases,also the proportion of stick area in contac area decreases dramatically,coming into slipping area with climbing rails;with the change of yaw angle,the contact area is almost the same,but when it goes to0.4°, the contact area comes in slip state,the proportion of stick area in contac area minish drasticly.