浮置板轨道二维建模及隔振性能分析

2-D Modelling of Floating Slab Track and Performance Analysis on Vibration Isolation

为分析轮对载荷相位差及浮置板弯曲振动模态对轨道隔振性能的影响,利用动柔度法建立二维浮置板轨道频域模型,浮置板简化为自由边界的Kirchhoff薄板,根据力的传递率分析轨道隔振性能。计算结果表明,轮对载荷存在相位差时将激起更多的浮置板弯曲振动模态,从而降低浮置板轨道的隔振性能。采用短浮置板可减少其结构模态数目,提高中频段的轨道隔振性能。当轮对载荷同相位时,可以用一维浮置板轨道模型(梁模型)进行分析计算。

In order to analyze the effects of phase difference of the wheelset loads and bending vibration modes of the slab on the vibration isolation performance of the floating slab track（FST）,a two-dimensional（2-D） model for the FST is developed by using the dynamic receptance method,where a rectangular Kirchhoff plate with free boundary at four edges is used to account for the slab.The vibration isolation effectiveness of FST is investigated based on the force transmission ratio.Simulation results show that more vibration modes of the slab are excited when the wheelset loads have some phase difference,resulting in a decrease in the vibration isolation performance around these modal frequencies.The FST with short slab gains better vibration isolation effectiveness at medium frequencies because of less vibration modes existing with comparison to FST with long slab.When the wheelset loads are in phase,the one-dimensional model（Euler-Bernoulli beam to account for the slab） for FST can be used for corresponding analysis instead of the 2-D model for simplicity,without causing errors.