高速列车车轮多边形对轴箱的影响分析

为分析高速列车轴箱端盖脱落的原因,建立了轴箱端盖的有限元模型,通过模态分析得到了580Hz的固有模态,并依据模态试验验证了模态分析结果。经过和线路试验数据对比发现该固有频率和20阶多边形的激励频率很接近,针对这一情况应用多体动力学软件建立了包含轴箱和端盖的车辆动力学模型并对轴箱端盖的振动特性进行分析。结果表明:端盖处的加速度要远远大于轴箱体上的加速度,结合频谱分析可以确定轴箱端盖处发生了共振,激烈的振动会使预紧力下降,当预紧力下降到2.5kN螺栓发生松动。上述结论与试验结果一致,并且根据测力螺栓的和端盖的试验数据可以发现随着螺栓预紧力的下降端盖的振动更加剧烈。本研究确定了引发高铁轴箱端盖掉落的根本原因,对于高铁车辆的安全运行有一定的指导借鉴意义。

Effects of Wheel Polygonalization on Axle Box for High Speed Train

In the light of the damage of axle box end cover on high speed train, First, the finite element model of the end cover is established for the modal analysis, where the intrinsic mode is captured at frequency around 580Hz. The results are verified by the later modal test and the comparisons with the field test data show that the intrinsic mode is quite close to the excitation frequency of 20-order wheel polygonalization. In response to this phenomenon, the vehicle multi-body dynamics model containing the axle box end cover is established by multi-body dynamics simulation software, and the vibration characteristic of the bolt and axle box end cover is analyzed. The simulation results show that the acceleration amplitude of axle box end cover is much larger than that of the axle box body. Furthermore, considering the spectrum analysis, the resonance of the end cover can cause the bolts to loosen, which probably happens when the preload drops to 2.5kN. The above conclusion is consistent with the test results, and another rule is found through the instrumented bolt: as the bolt preload decreases, the acceleration of end cover increases. This paper shows the reason of end cover destroy, and it is of great significance for the running safety of the high speed train.