Research On Wheel-Rail Wear Of Heavy Haul Freight Car

With the rapid growth of the railway transportation volume, the heavy haul transportation has become the direction of the development of China's railway freight. However, with the increasing of the train load, the applying of more and more trucks, large power diesel locomotives and electric locomotives leads to the serious problem of wheel-rail wear. Not only the range of wheel-rail wear is extending from small radius curves to large ones, but also the speed of wheel-rail wear is becoming faster than before. The maintaining and replacing cycle is shortened enormously, thus, the problem of replacing steel rail and wheel prematurely not only make the railway transportation cost increasing, but also effect the railway normal transportation.The wheel-rail wear is inevitable in wheel-rail system and its reason is very complicate. Most researches have indicated that wheel-rail wear is resulting from comprehensive function of multiple factors, and the heavy haul freight car bogie plays a very important role. Therefore, researching and analyzing the wheel-rail wear of the heavy haul freight car bogie will be beneficial to decreasing the transport cost, reducing the environmental pollution and improving the transport efficiency. It is practical to study this issue for the development of the heavy haul transportation.Firstly, the development of the heavy haul transportation at home and abroad were reviewed, and the main reasons that increasing the wheel-rail dynamic force and wheel-rail wear were analyzed. Then, the wheel-rail contact relation, wear mechanisim and its relevant evaluation method were introduced briefly, and the pre-conditions for using these evaluation methods were summrized. Subsequently, with analyzing the characteristics of three kinds of heavy haul freight car bogies, the dynamic models were established by using multi-body system dynamics simulation software SIMPACK.Based on the above analysis and dynamic models, study on the effects of relevant parameters of three-piece bogie on the wear were made. Also, the effect of the axle load on the wheel-rail wear was analysised. The influence of three kinds of heavy haul freight bogeis with different structural modes on the wheel-rail wear was compared. In addition, the influence degree of the related curve parameters on wear was analysised in the fifth chapter. Finally, the relevant parameters effectting the rolling contact fatigue of rail were study by using the RCF damage function.The researched results indicate that the parameters which have a great influence to the wheel-rail wear include longutiual sfiffness of the axle box, the friction coefficient of the center plate and the side bearing, the warp stiffness, the curve radius, the deficient superelevation, the rail base slop and the axle load. It is indicated that the side frame radial bogie can reduce the wheel-rail wear vigoursly. Factors which have a great effect on the rolling contact fatigue are the curve radius and the bogie properties. So, the reasonable setting of the suspension parameters and the line parameters is two more effective ways to decrease the wheel-rail wear and rolling contact fatigue.