动车组车轮多边形磨耗形成与发展过程仿真研究

针对动车组车轮多边形磨耗愈发严重的问题,基于车辆-轨道耦合动力学模型、轮轨接触模型、Archard磨耗模型和循环迭代模型,建立车轮多边形磨耗长期磨损迭代模型;模拟我国某型高速动车组20阶车轮多边形的发展过程,结果与实际情况吻合,证实模型的准确性。基于长期磨损迭代模型,研究车辆运行速度、轮轨模态振动特性和轨道参数对车轮多边形发展的影响。结果表明:随着车辆运行速度增大,最终形成的车轮多边形主导阶次逐渐减小,但产生的激励频率始终在550~600 Hz之间,验证了“频率固定”机理的可靠性;对比分析柔性轮轨、刚性轮柔性轨、柔性轮刚性轨、刚性轮轨4种工况下车轮多边形的发展过程,发现钢轨模态的振动特性对于高阶车轮多边形的产生具有一定的促进作用;增大扣件的刚度可抑制高阶车轮多边形的产生和发展,而增大扣件阻尼则可抑制车轮多边形整体的发展速度。

Numerical Simulation on the Formation and Development of Polygonal Wear of EMU Wheels

In view of the increasingly serious problem of the polygonal wear of EMU wheels,based on the vehicle-track coupling dynamic model,wheel-rail contact model,Archard wear model and cyclic iterative model,a long-term wheel polygon wear iterative model was established.The development process of 20-order wheel polygon of a certain type of high-speed EMU in China was simulated.The simulation results were consistent with the actual situation,and the accuracy of the model was verified.Based on the long-term wear iterative model,the influence of vehicle speed,wheel-rail modal vibration characteristics and track parameters on the development of wheel polygons was studied.Results show that as the vehicle running speed increases,the dominant order of the final wheel polygon decreases gradually,but the generated excitation frequency is always between 550 and 600 Hz,which verifies the reliability of the“frequency fixation”mechanism.The development process of wheel polygons under four working conditions,namely,flexible wheel rail,rigid wheel flexible rail,flexible wheel rigid rail and rigid wheel rail,is compared and analyzed.It is found that the vibration characteristics of the rail modal have a certain promotional effect on the generation of high-order wheel polygons.Increasing the stiffness of the fastener can restrain the generation and development of high-order wheel polygons,while increasing the damping of the fastener can inhibit the overall development speed of wheel polygons.