车轮多边形演变及其对车辆动力学影响

Polygonal evolution of wheels and its effect on vehicle dynamics

车轮多边形演变会影响动车组运行安全,为研究其演变过程以及对车辆振动行为的影响,对国内某动车组车轮进行实际廓形测量和分析。基于车辆动力学理论和滚动接触理论,建立车辆-轨道耦合动力学模型,从时域和频域角度仿真分析多边形磨耗特征。假设车轮横向轮廓和名义车轮半径不发生变化,结合USFD磨耗模型建立长期磨损迭代模型来模拟多边形演变行为,并利用实测不圆顺数据分析对动力学性能的影响。计算结果表明:最终圆周轮廓与初始轮廓存在相位差,车轮磨耗虽增加但波形变化不大。车轮多边形对平稳性指标影响较小,但会影响轮轨动作用力,轮轨垂向力最大值随车轮不圆顺波长的增大而降低,随速度和粗糙度幅值增加而增大。同等行车速度下粗糙度幅值增大,构架垂向加速度幅值相应增大。

The polygonal evolution of wheels affects the operational safety of EMUs. In order to study the evolution process and its effect on vehicle vibration behaviors, the wheel profile of an EMU in China was measured and analyzed. Based on the vehicle dynamics theory and rolling contact theory, a vehicle-rail coupling dynamics model was established, and the characteristics of polygonal wear were simulated from angles of view of the time domain and frequency domain. Assuming that the lateral wheel profile and nominal wheel radius were unchanged, a long-term wear iterative model was established in combination with the USFD wear model, to simulate the polygonal evolution behaviors, and the effect on the dynamic performance was analyzed on the basis of the measured out-of-roundness data.The results show that there is a phase difference between the final circumferential profile and the initial profile, and the waveform changes little with worsening wheel wear. The wheel polygon has little effect on the running stability index, but it affects the wheel-rail dynamic interaction. The maximum wheel-rail vertical force decreases with the increase of wheel out-of-roundness wavelength, and increases with the increase of speed and roughness amplitude. At the same driving speed, the vertical acceleration amplitude of the frame increases with the increase of the roughness amplitude.