轮轴弯曲刚度对轮轨垂向动态载荷影响分析

以国内某型地铁车辆为例,研究轮轴弯曲刚度对轮轨垂向动态载荷和轮对垂向振动的影响。在常规多刚体动力学模型的基础上,结合BM3000轮对和北京地铁轮对两种不同的弹性轮对模型,对比分别采用刚性轮对模型和弹性轮对模型时的轮对垂向振动加速度和轮轨垂向力。结果表明,对BM3000弹性轮对模型来说,由于其弯曲刚度相对较小,随着运行速度的增大,轮对垂向振动加速度和轮轨力与刚性轮对的差距不断加大,而对于轮轴弯曲刚度较大的北京地铁轮对来说,其弹性轮对模型和刚性轮对模型的结果比较接近,在计算的速度下轮对的振动峰值及频率均有明显的降低。因而,通过加大轮轴弯曲刚度可明显改善轮对的垂向振动和轮轨垂向力,实现改善轮轨动态接触状态的目的。

Influence of the Wheel Axle Bending Stiffness on the Wheel/rail Vertical Dynamical Load

The influence of the wheel axle bending stiffness to the wheel/rail vertical dynamical load and wheelset vertical vibration was investigated on a vehicle of the Beijing metro railway.Based on the general multi-body dynamics model and the two kinds of elastic wheelset models,combined with BM3000 type wheelset and the wheelset adopted by the vehicles of the Beijing metro railway,a comparison is carried out between the wheelset vertical vibration and the wheel/rail vertical contact force which adopted the rigid and elastic wheelset model.Simulation results show that the wheelset vibration and the wheel/rail contact force of the elastic wheelset model is different with that of the rigid wheelset model;this is due to the BM3000 type wheelset not having high enough bending stiffness,the deviation between the two models increases with running speed.In contrast,the results of the elastic wheelset model of the wheelset of the Beijing metro railway vehicle is quite similar to the results of the rigid model and both the wheelset vibration value and frequency exhibit an obvious decrease since it has a larger bending stiffness.Consequently,the wheelset vibration and wheel/rail contact force can be improved by increasing the wheel axle bending stiffness which will improve wheel/rail dynamic contact conditions.