采用双向调谐质量阻尼器的大跨度桥梁风振控制仿真分析

传统的调谐质量阻尼器（TMD）设计均仅针对结构某一阶模态单独设置,当用于密频结构减振时会导致附加质量过多。为减小TMD的附加质量,结合大跨度斜拉桥结构的密频与风致耦合振动特点,提出了一种新型的双向共享质量与电涡流阻尼式TMD。具体实现方式是：水平、竖向TMD的刚度构件分别采用悬臂梁与压簧,将水平向TMD整体置于压簧上面,从而构成竖向TMD的质量;导体板固定不动,使安装在TMD质量块的永磁体阵列随质量块竖向或水平方向运动,从而分别产生竖向与水平向的电磁涡流阻尼。研究结果表明：（1）电涡流阻尼可以很好地实现双向TMD装置的共享阻尼,且电涡流阻尼的大小可以很方便地调节;（2）采用双向TMD进行斜拉桥的风致振动控制减振效果良好,可行性强。

Numerical Analysis of Wind-induced Vibration Control of a Longspan Bridge with Bi-directional Tuned Mass Dampers

Traditional tuned mass damper （TMD） is generally designed for a single mode of structures. However, when it is applied to structures with closely spaced natural frequencies, supplemental mass of TMD will be too huge. To decrease extra mass of TMD, a new bi-directional TMD with shared mass and eddy current damping is developed in view of wind-induced coupled vibration of long-span cable-stayed bridges with closely spaced natural frequencies. The cantilever beam acts as the stiffness components of horizontal TMD, while pressure spring is adopted as the stiffness members of vertical TMD. Horizontal TMD is set at the top ot vertxcai livlu as a whole, thus all the mass of the horizontal TMD is used as the mass of vertical TMD. As such, shared mass is realized. Since conductive plate is fixed and permanent magnet array is mounted on the TMD, when the mass of TMD moves in vertical or horizontal direction in line with main structures, corresponding vertical or horizontal eddy current damping will he generated. Therefore, shared damping components are achieved. The results show that. （1） Eddy-current damping can make horizontal and vertical TMD share the same damping components very well, moreovet, the value of eddy current damping is easily adjusted; （2） the proposed hi-directional TMD is suitable and feasible for wind-induced vibration control of long span cable-stayed bridges.