基于微型永电磁式涡流阻尼TMD的人行桥模型减振试验研究

摘要

Traditional tuned mass damper (TMD)adopted for vibration control model test of civil engineering structures has several obvious disadvantages.It can’t well separate the damping and stiffness components,and the damping coefficients can’t be kept constant during the movement of TMD.In addition,it is difficult to adjust the damping coefficient during the control performance tuning in the test.By performance tests and analysis,it is proved that a developed tiny TMD with eddy-current damping can successfully solve the above problems.The great advantage of the proposed TMD is that its damping ratios can be easily adjusted by changing the thickness of conductor plates.Finally,the model test on lateral vibration control of a footbridge further demonstrates the feasibilities and effectiveness of the developed TMD based on the identification of modal damping ratios of structure subjected to both free vibration and forced vibration excitation,and on the measurement of structural dynamic response magnification as well as the phase between the main structure and TMD in the forced vibration excitation tests.%针对现有结构模型减振实验用调谐质量阻尼器（Tuned Mass Damper，TMD）难以实现TMD刚度与阻尼参数完全分离、阻尼参数试验过程中无法保持恒定且难以调整问题，研制微型永磁式电涡流阻尼TMD。其性能试验与分析结果表明，微型TMD采用电涡流阻尼装置既能确保刚度与阻尼参数的有效分离，亦能实现阻尼参数稳定、简单易调。通过某大跨度人行桥模型一阶横向振动模态自由振动减振实验识别获得结构模态阻尼比及强迫振动减振实验识别获得结构模态阻尼比、结构动力响应放大倍数、结构与TMD运动相位差等，证实微型永磁式电涡流阻尼TMD用于结构模型减振实验的可行性与有效性。