周期性浮置板轨道弹性波传播行为及波动效应

Propagation Behavior and Wave Effect of the Track Elastic Wave of Periodic Floating Plate

为探究复杂周期性浮置板轨道结构中的弹性波传播行为及波动效应的内在机理,基于无限周期结构的弹性波理论建立浮置板轨道结构模型,计算并分析结构带隙特征、弹性波传播机制以及移动荷载激励下的波动效应。结果表明:复杂周期性浮置板轨道结构在0~300 Hz范围内存在8个带隙,且带隙可阻碍弹性波在结构中的传播;带隙特征主要受结构刚度影响,可通过改变钢弹簧刚度、剪力铰剪切刚度和基础分布刚度来调节带隙范围;由于浮置板、轨道和隧道衬砌结构的弹性波局域共振作用,浮置板轨道结构减振效果在0-√2倍共振频率范围内劣于整体道床轨道结构,而在大于√2倍共振频率时才优于整体道床轨道结构;结构加速度响应峰值由荷载速度线与频散曲线的交点所产生,带隙和通带范围内弹性波存在不同的波动效应,且带隙对弹性波正向多普勒效应具有抑制作用。

To investigate the inherent mechanism of elastic wave propagation behavior and fluctuation effect in the track structure of the complex periodic floating plate,the model of a floating plate track structure is established based on the elastic wave theory of infinite periodic structure;and the band gap characteristics,propagation mechanism of the elastic wave and fluctuation effect under the excitation effect of moving load of the structure are calculated and analyzed.The results show that there are 8 band gaps within the range of 0-300 Hz in the track structure the complex periodic floating plate,and the band gaps can hinder the propagation of elastic waves in the structure.The band gap characteristics are mainly affected by the stiffness of the structure,and the band gap range can be adjusted by changing the steel spring stiffness,the stiffness of shear hinge cut and the base distribution stiffness;due to the local resonance effect of elastic waves in the floating plate,track and tunnel lining structure,the floating plate track The vibration reduction effect of the structure is inferior to the overall bed track structure in the range of 0-√2 times resonance frequency,but better than the overall bed track structure only when it is greater than √2 times resonance frequency;the peak acceleration response of the structure is generated by the intersection of load velocity line and dispersion curve,and there are different fluctuation effects of elastic wave in the band gap and through-band range,and the band gap has a suppressive effect on the forward Doppler effect of elastic wave.