应用动力吸振器的浮置板轨道低频振动控制特性的试验研究

Experimental Study on Low-frequency Vibration Control Characteristics of Floating Slab Track Using Dynamic Vibration Absorbers

针对浮置板轨道在低频域出现的振动放大问题,通过落轴试验研究应用动力吸振器浮置板轨道的低频振动控制特性。基于多自由度等价质量识别原理与扩展定点理论,利用浮置板轨道有限元模态分析与室内测试,设计合理的动力吸振器关键参数,将制作好的动力吸振器安装在实验室实尺浮置板轨道上进行落轴冲击动力学试验,以研究动力吸振器对浮置板轨道低频振动特性的控制效果。研究结果表明:在试验条件下,动力吸振器可以明显降低浮置板轨道在10 Hz基频附近的振动加速度,且质量比越大振动控制效果越好;与传统无动力吸振器的浮置板轨道相比,当动力吸振器的质量比为0.3时,轨道板、支承层的插入损失最大分别可达15.3、11.9 dB。

In order to solve the vibration amplification problem of floating slab track(FST)in low frequency domain,the low-frequency vibration control characteristics of FST with dynamic vibration absorber(DVAs)were studied through wheel-drop experiment.Based on the identification method of equivalent mass for multi-degree-of-freedom systems and extended fixed-point theory,the key parameters of DVAs were designed and manufactured combined with the finite element modal analysis and indoor modal test of the FST.Further,the DVAs device was installed on the full-scale FST in the laboratory to perform the wheel-drop impact test to study the control effect of DVAs on the low-frequency vibration characteristics of the FST under the impact load.The results indicate that the values of the vibration acceleration of the FST using the DVAs are significantly less than those of the FST without the DVAs at the natural frequency of 10Hz,and the effect of the vibration control is improved with the increase of the mass ratio of the DVAs.Compared with the traditional FST without DVAs,when the mass ratio of the DVAs is 0.3,the maximum insertion losses of the slab and the bearing base can reach 15.3 dB and 11.9 dB,respectively.