Multi-mode cable vibration control using a viscous-shear damper: Case studies on the Sutong Bridge
Multi-mode cable vibration control using a viscous-shear damper: Case studies on the Sutong Bridge
复制标题
使用粘性剪切阻尼器的多模式缆索振动控制：苏通大桥案例研究
DOI：
10.1002/stc.2536
复制
发表时间：
--
影响因子：
5.4
通讯作者：
Wang Lujun
中科院分区：
文献类型：
--
作者：
Chen Lin;Di Fangdian;Xu Yuyuan;Sun Limin;Xu Yingmei;Wang Lujun
本研究探讨黏滞剪力阻尼器（VSD）对长拉索的多模态阻尼效应。典型的VSD包括容纳粘性介质的壳体箱和剪切板，剪切板的部件浸没在介质中。它通过粘性介质的剪切变形耗散振动能量。VSD成本低，不易发生泄漏或增加关节间隙，因此维护工作量低。为研究其对长拉索的阻尼效应，对主跨1,088 m的苏通大桥的3根长拉索分别设计了3个可变阻尼器，并在不同频率和幅值的正弦强迫位移作用下进行了室内试验。它们的动力学行为被发现是准确地使用粘性阻尼器与固有刚度，而粘性和刚度系数依赖于频率和振幅。随后将VSD分别连接到拉索上，通过自由衰减试验测量了无阻尼器和有VSD的每根拉索的面内模态的模态阻尼比。对频率小于3 Hz的大多数面内模态的测量结果表明，与理想的粘滞阻尼器相比，VSD提供了令人满意的多模态阻尼效果，效率因子在30%至50%之间，并且对于更高的模态，阻尼略有下降。测量结果也与考虑频率和振幅相关的阻尼器特性的具有Kelvin-Voigt阻尼器的浅缆的复模态分析结果一致。特别是，使用在小变形振幅下测试的阻尼器特性的分析预测提供了阻尼效果的下限。
This study investigates multimode damping effects of a long cable attached with a viscous‐shear damper (VSD). A typical VSD comprises a casing box containing viscous medium and shearing plates with parts submerged in the medium. It dissipates vibration energy through shear deformation of the viscous medium. The VSD is low‐cost and invulnerable to leakage or increasing joint play and hence requires low maintenance effort. For studying its damping effects on long cables, three VSDs were designed respectively for three long cables of the Sutong Bridge, a cable‐stayed bridge with a main span of 1,088 m, and then tested in laboratory under forced sinusoidal displacements with various frequencies and amplitudes. Their dynamic behaviors were found to be accurately modeled using a viscous damper with intrinsic stiffness, while the viscous and stiffness coefficients depend on frequency and amplitude. The VSDs were subsequently attached to the cables respectively, and modal damping ratios of in‐plane modes of each cable without dampers and with the VSD were measured by free‐decay testing. The measurements obtained for most in‐plane modes with frequency less than 3 Hz show that the VSD provides satisfactory multimode damping effects with efficiency factors between 30% and 50% as compared to an ideal viscous damper and the damping decreases slightly for higher modes. The measurements are also found consistent with the results of complex modal analysis of a shallow cable with a Kelvin–Voigt damper considering frequency‐ and amplitude‐dependent damper properties. Particularly, analytical prediction using the damper properties tested under small deformation amplitude provides the lower bound of the damping effect.