As high-speed trains operate at a higher speed, the problem of rail wear is more serious. In this paper, a new Gaussian function correction (GFC) method is proposed to design the new rail profile, two parameters are introduced to control the removal area. Then a high-speed train vehicle dynamic model is established, the Kriging surrogate model (KSM) is used to reduce the number of simulations and the Non dominated sorting genetic algorithm-II (NSGA-II) algorithm is used to optimize the rail profile. Finally, the dynamic characteristics and wheel/rail wear evolution of the optimized profile are analyzed. The results show that the dynamic performance of the optimized rail profile has been improved. The maximum wear depth of the optimized rail profile is reduced by 15.63% when passing a total weight of 16 Mt. The wheel wear depth of S1002CN profile contact with CHN60OPT is reduced by 4.8%. The proposed GFC method can quickly generate a new rail profile and has good engineering significance for rail grinding. The GFC-KSM-NSGA- II method can be used to optimize the rail profiles for high-speed lines, and it can further guide the operation and maintenance.

Wheel wear prediction for high-speed railway vehicles during the acceleration process is of great importance for the improvement of operating characteristics and the development of friction management strategy near the railway station, especially in complex climatic environments. This work analyzes and predicts the wheel wear evolution of high-speed motor cars during acceleration. Firstly, detailed dynamic models of the high-speed motor car are developed, in which a comprehensive gear transmission system is also adopted to capture the accurate dynamic responses of the motor car. Secondly, the length of the simulated track interval with different friction coefficients is set according to the Gaussian distribution function to consider the influence of the friction coefficient. Moreover, a Proportional-Integral(PI) creep controller is also introduced to meet the challenge due to varying wheel-rail contact conditions, and a wheel wear prediction model based on the aforementioned submodels is established to obtain the wheel wear evolution. Finally, simulation results of dynamic responses from the vehicle dynamic model and wheel wear prediction procedure are compared with the measured field data. The results show that the time-varying meshing stiffness from the gear transmission system will aggravate the interaction between wheel and rail and deteriorate the wheel wear. When the high-speed motor car passes through a poor adhesion zone in the acceleration, it is easier to trigger the creep controller at the low-speed period while it will not occur at the high-speed period.

Wheel/rail wear is one of the key issues in the safe operation of a high-speed railway motor car. This paper analyzes and predicts the wheel wear evolution of motor car during the long-term operation process. Firstly, the detailed motor car with gear transmission systems and trailer car of the high-speed train, which take into account various non-linear factors such as dampers, bump stops, wheel/rail contact relation, etc., are developed to obtain interaction force between wheel and rail. Secondly, according to the tread update strategy based on fixed travel distance, a novel wheel wear prediction model integrating the Archard wear model and previous dynamics system is established. In order to more accurately obtain the dynamic responses of the motor car, the comprehensive gear transmission system coupling with motor bogie is also built, which considers the time-varying mesh stiffness and gear shift coefficient. And the corresponding traction characteristic curve is also applied to the gear transmission system. Finally, the wheel wear evolution in one re-profiling cycle is simulated to verify the developed model, and the wheel wear mechanism is investigated in detail. Furthermore, the influence of traction velocity on wheel wear is also investigated. The simulation shows that the cumulative wear amount of both two cars increases gradually and the wear rate decreases gradually with traveling mileage, but the wear rate of the trailer car decreases faster than that of the motor car due to larger longitudinal creepage and longitudinal creep force induced by traction torque. Moreover, the max wheel wear depth and wear bandwidth for motor car gradually increase with traction velocity. While the discrepancies of the max wheel wear depth and wear bandwidth for trailer car are small under different speeds.

The yaw damper is of great significance to the dynamic performance of high-speed trains. In this work, the influence of different installation angles of yaw dampers on dynamic responses and wheel wear is investigated. Firstly, the detailed dynamic model of a high-speed train is developed, which includes all kinds of nonlinear factors, such as wheel/rail contact relationship and nonlinear characteristics of various damping, and the influence of the installation angle of the yaw damper on dynamic performances of railway vehicles is investigated. Then the wheel wear prediction procedure is also proposed to obtain the effect of the installation angle of the yaw dampers on wheel wear evolution. The results show that the nonlinear critical speed of railway vehicles gradually increases with the increasing lateral distance of the yaw damper at the frame side. While critical velocity gradually decreases with increasing vertical installation distance of the yaw damper at the car body side. The maximum wheel wear depth will also gradually increase with increasing vertical distance at the car body side and increasing lateral distance of the yaw damper at the frame side when the vehicle runs on the tangent track. Moreover, it is also noticed that the wear depth of the wheel on both sides will gradually increase with the increasing vertical installation distance of the yaw damper at the car body side when the vehicle runs on a curved track. When the lateral installation angle of the yaw damper is less than 0°, the wheel wear rate remains constant and the wear sensitivity of the wheel to lateral installation angle is low, if the lateral installation angle of the yaw damper is greater than 0°, wheel wear rate increases significantly with increasing lateral installation angle of the yaw damper.