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运用无穷周期子结构的辛数学方法与虚拟激励法,建立了车辆-轨道垂向耦合随机振动虚拟辛分析模型,并用以探讨扣件胶垫频变刚度对轮轨耦合系统随机振动的影响。研究结果表明:扣件胶垫频变刚度对车体垂向随机振动的影响可忽略不计,但却会改变转向架中高频的垂向随机振动幅值,同时还会显著提高轮对与钢轨的垂向随机振动最大功率峰与其第一主频;轮对垂向随机振动最大功率峰与其第一主频随着扣件胶垫刚度频变幅度或低频初始刚度的增大分别呈波浪式渐增与阶梯式上升的变化趋势;在铁路常用扣件胶垫刚度的变化范围内,轮对垂向随机振动最高功率峰的最大增幅是17.5倍,并且其第一主频的最大增量亦可高达40 Hz。因此,为精确预测车辆转向架、车轮及轮下系统的随机振动频域响应,需综合考虑扣件胶垫的低频初始刚度及其刚度频变幅度。
By using the symplectic method and virtual excitation method with infinite periodic substructure, a virtual symplectic analysis model of vehicle-track vertical coupling stochastic vibration is established and the effect of frequency-dependent stiffness of fastener on stochastic vibration of the wheel-rail coupling system is discussed. The results show that the influence of frequency-dependent stiffness of the fastener on the vertical random vibration of the car body is negligible, but it will change the vertical random vibration amplitude of the high frequency in the bogie, meanwhile, the wheelset and the rail Vertical maximum random vibration power peak and its first main frequency; vertical random vibration maximum power peak and its first main frequency with the buckle pad stiffness frequency variation amplitude or low frequency initial stiffness were increased wave-shaped And the trend of stepwise increase. The maximum amplitude of the maximum peak of vertical random vibration in the variation range of the stiffness of commonly used fasteners in the railway is 17.5 times, and the maximum increment of the first frequency can be as high as 40 Hz. Therefore, in order to accurately predict the random vibration frequency response of vehicle bogies, wheels and wheel-down systems, the initial low-frequency stiffness of the buckle pad and its stiffness variation should be considered.