The Study Of Rail Wear Mechanism And Its Application Based On Finite Element Method

With the increase of axle load,extension of vehicle marshalling and ascension of driving speed,rail wear problem has become serious gradually.There are two very important problems when use test and in-situ observation to study the wheel/rail wear problem.One problem is the long cycle,the other one is the high cost;in the using of the multi-body system dynamics program to study the wheel/rail wear problem,the material is linear elastic,and the result is two-dimensional.To this end,the paper uses ABAQUS finite element simulation software to analyze the wheel/rail rolling elastic-plastic contact on straight line by simulation and numerical calculation,studys the wear rule of wheel/rail under steady elastic-plastic contact,and implements three-dimensional display of the rail wear,achievements will play a certain guiding role in research of optimization of wheel/rail profile and reduction of rail wear value.The main work in the paper are listed as follows:(1)On the basis of the wheel/rail rolling theory and elastic-plastic theory,use ABAQUS finite element software to establish the 3D wheel/rail contact model,analyze the four kinds of working condition of wheel/rail contact: static elastic contact,static elastic-plastic contact,steady elastic contact and steady elastic-plastic contact.Through analyzing and comparing four kinds of wheel/rail contact conditions,get the following conclusion: compared with other conditions,in the condition of wheel/rail steady elastic-plastic contact,wheel/rail rolling contact and the actual elastic-plastic material of wheel/rail are taken into account.In this condition,rail plastic strain is the most serious,the friction has an obvious spin motion on the rail surface,so the wheel/rail static elastic-plastic contact condition is more in line with the actual working condition,use finite element method to study rail wear problem need to be based on this condition.(2)Based on the condition of wheel/rail steady elastic-plastic contact,use the established 3D wheel/rail contact model in ABAQUS,and select the Archard model for the wear model,define an angle coordinate system to measure rail wear,discuss thecharacteristics of wheel/rail contact and wear rule in two kinds of working condition:flange close contact with rail side stick and center wheel tread contact with rail top surface.Finally overlay the results of the two kinds of working condition for overlay analysis to obtain wear rule of total cross-section of rail.Results show that rail wear on its cross section presents the bigger in the middle and the smaller on both ends,the maximum of rail wear is in direction of gauge side and in the position of 17 mm from the centerline of rail.Compared with using multi-body dynamics method formerly,material of wheel/rail finite element model is elastoplastic,which is closer to the real condition of wheel/rail contact.(3)Analyze the the influence of different friction coefficient,transverse quantity of wheel,wheel-rail attack angle on rail wear.The results show that vertical wear of rail head increases with the increase of friction coefficient;with the increase of transverse quantity of wheel the rail wear has a trend to move to the no working surface of rail on the whole,the maximum value of rail wear decreases with the increase of transverse quantity of wheel on straight line;the change of wheel-rail attack angle has no obvious influence on value of rail,but it has a certain influence on the form of contact spot and wear spot mainly on straight line;the maximum value of rail wear increase with the increase of vehicle speed.