MTMDs对浮置板轨道结构隔振性能的影响分析

Effect of MTMDs on the Vibration Isolation of Floating Slab Track

本文建立车辆-浮置板轨道-MTMDs(调谐质量阻尼器)垂向耦合振动频域模型,其中车辆被视为2个转向架双层悬挂的多刚体系统、钢轨被视为离散点支承的无限长Timoshenko梁、浮置板被视为Kirchhoff薄板结构、MTMDs简化为质量-弹簧模型、扣件和板下钢弹簧被视为线性弹簧阻尼单元,通过Matlab软件编制程序计算分析在轨道不平顺作用下MTMDs及MTMDs与基体的质量比对浮置板隔振性能的影响。研究结果表明:在轨道不平顺激励下,针对浮置板轨道固有频率设计的MTMDs能够较有效抑制浮置板结构在固有频率附近的振动放大,同时也能减小扣件系统的力传递率和浮置板垂向振动加速度;MTMDs质量的变化在浮置板固有频率附近产生较大影响,在其他频段几乎不产生影响。在浮置板轨道固有频率附近,随着MTMDs质量的增加,浮置板轨道力传递率峰值、扣件的力传递率峰值以及浮置板垂向加速度功率谱峰值越小,其振动控制率越大。MTMDs总质量与浮置板质量比为0.1时,其在浮置板固有频率附近对浮置板力传递的控制率达到30%以上,已较好抑制浮置板在固有频率附近对振动的放大。

A vehicle‐floating slab track‐M TMDs vertical coupled dynamic model was developed in frequency do‐main ,where the full vehicle was considered as a multi‐rigid‐body system with a pair of two‐axle bogies with double suspension systems ;each rail in the track was modeled as an infinite Timoshenko beam discretely sup‐ported by fasteners ;the floating slab track was considered as Kirchhoff thin plate structure ;,the M TMDs were considered as a mass‐spring model;and the fastener and the plate steel spring were considered as linear spring damper elements . .Through Matlab software programming ,the influences of MTMDs under track irregulari‐ty ,particularly ,the effect of the mass ratio of all MTMDs to floating slabs on the isolation‐vibration perform‐ance of floating slabs ,were calculated and analyzed .The results showed that ,under track irregularity excita‐tion ,M TMDs designed according to the natural frequency of floating slab track can control effectively vibration amplification near the natural frequency of floating slab structure and can reduce the force transfer ratios of the fastening system and the vertical vibration acceleration of the floating slab .Changes of M TMDs mass had a sig‐nificant impact on isolation‐vibration near the natural frequencies of floating slab track ,while the changes hard‐ly imposed effects in other frequency ranges .Near the natural frequencies of floating slab track ,the more the M TMDs masses ,the lower the peak of force transfer ratio of floating slab track and fastening system and the vertical vibration acceleration of the floating slab w as ,w hereas the larger the vibration control rate w as .When the mass ratio of all MTMDs to floating slab was 0 .1 ,and the force transfer control rate in the floating slab near the natural frequency exceeded 30% , the vibration suppression effect on vibration amplification of the floating slab near the natural frequency was better .