Study On Rail Wear Prediction Of Heavy Haul Railway

Heavy-haul railways,as the most advanced and effective technical means in the transportation of railway freight goods,have been widely used and developed in the world and will help to improve the contradiction between supply and demand of our country's current cargo transportation.However,a serious wheel and rail wear occur in the course of the use of heavy-haul railway,bring about an increase of transport costs,endanger the safety of vehicles,and restrict the development of heavy rail eventually.In order to ensure the healthy and rapid development of heavy rail transport,it is necessary to carry out a large number of on-site and simulation research on rail wear and related problems.However,it is necessary to establish a complete vehicle-track dynamic model,although heavy-haul railways rail wear simulation only related to the wheel-rail system.Based on the UM dynamics calculation software,a rail wear prediction model based on vehicle-track system dynamics theory,three-dimensional wheel-rail contact mechanics theory and Archard material wear theory are established.The vehicle is simplified as multi-rigid-body system with 90 freedom,and the non-linear components such as friction damper,cross bracing rod and axial positioning device are considered in detail.The multi-point-surface contact model is used to simulate the contact friction,and fully consider the component stop gap.The track system is considered as a lumped parameter model,taking into account the inertia characteristics of the rail and its lateral,vertical,translational motion and rotation around the longitudinal.The elastic support layer of the rail is simulated by the spring and damping element according to the principle of certain equivalence.The rail connect with the rigid foundation through the elastic support layer,regardless of the influence of sleeper and ballast bed.Calculation of wheel/rail contact is based on Hertz theory and Kalker simplification theory;Calculation of rail wear is based on Archard material wear model.For a variety of vehicle and speed,carry out multiple operating conditions and set the weight factor to simulate the actual driving conditions of the track line,use different wear factors according to the wear condition.In order to improve the numerical calculation stability,rail surface update when cumulative wear depth reaches 0.1mm.The vehicle stability is calculated to validate the accuracy of the established by compared with vehicle-track coupling dynamics model proposed by Zhai Wanming.The measurement of the profile of different sections of Shuo-Huang Railway was carried out to master the wear characteristics of rails in different curve sections.Based on the wear evolution model,the development rules of rail wear in different curve sections of heavy-haul railway are studied.The wear and development of 60kg/m and 75kg/m rails are studied respectively.The evolution process and characteristics of rail wear under different track line,rail type and vehicle operating conditions are obtained to clarify the law of rail wear of heavy rail railway in China.The influence of rail wear on the dynamic behavior of heavy-haul vehicle is studied.Based on the safety of vehicle operation,the rail grinding maintenance cycle of different radius curve are proposed.The key factors affecting the rail wear are investigated in detail,and the mitigation measures for rail wear of heavy rail are put forward based on the survey results.