考虑轨道弹性时机车轮对的纵向振动研究

INVESTIGATION ON LONGITUDINAL VIBRATION OF LOCOMOTIVE WHEELSET BY CONSIDERING TRACK ELASTICITY

在电机轴悬式机车-轨道垂向耦合动力学模型的基础上,考虑了机车的纵向运动自由度,通过对比牵引工况下考虑和不考虑轨道弹性时的轮轨作用力及轮对振动加速度,得到了轨道弹性变形对轮对轮轨切向力及其纵向振动的影响规律。研究结果表明,当轮轨界面无不平顺激扰时,考虑或忽略轨道结构的弹性对轮对牵引力的发挥及纵向振动影响不大;在不平顺激扰下,轨道结构参与轮轨间的耦合振动,由于轨道垂向的弹性及阻尼作用,轮轨垂向力特别是高频力得到缓冲及衰减,致使50Hz以上高频段的轮轨切向力及轮对纵向振动变的缓和,利于轮周牵引力的稳定发挥。总体上,分析模型中若不考虑轨道弹性会造成预测的轮轨切向力及轮对振动加速度偏大。

Based on a vertical locomotive-track coupled dynamic model with an axle hung motor driver, the longitudinal freedoms of a locomotive were taken into account. Under driving conditions, the influence of track elasticity on the locomotive traction property was obtained, by comparing the wheel/rail forces and vibration accelerations of a wheelset on a rigid track and an elastic track respectively. The research results indicate that the traction properties and longitudinal vibration of a wheelset for two track types differ slightly when no track irregularity exists on a wheel/rail contact interface. Subjected to a track irregularity excitation, the track structures will participate in a wheel/rail coupled vibration. Due to the effect of flexibility and damping in a track system, the wheel/rail vertical force can reduce effectively, especially for the high frequency forces. As a result, the wheel/rail tangential forces and longitudinal vibration of a wheelset above 50Hz are alleviated, and the tractive effort on wheel rim is improved. Overall, if track elasticity is not considered in this analysis model, the calculated wheel/rail dynamic forces and vibration accelerations of a wheelset are slightly bigger.