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.

中文翻译：

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使用粘性剪切阻尼器的多模电缆振动控制：以苏通大桥为例

这项研究研究了一条长电缆与粘性剪切阻尼器（VSD）的多模阻尼效应。典型的VSD包括一个装有粘性介质的套管和一些浸没在介质中的剪切板。它通过粘性介质的剪切变形来耗散振动能量。VSD成本低廉，不易泄漏或增加接头间隙，因此维护工作量少。为了研究其对长电缆的阻尼影响，分别为苏通大桥（主跨为1,088 m的斜拉桥）的三条长电缆设计了三个VSD，然后在实验室中在各种频率和振幅的正弦正弦位移下进行了测试。 。发现它们的动态行为可以使用具有固有刚度的粘性阻尼器精确建模，而粘性和刚度系数取决于频率和幅度。随后将VSD分别连接到电缆，并通过自由衰减测试来测量每根不带阻尼器且带有VSD的电缆的平面模式的模态阻尼比。对大多数频率低于3 Hz的平面模式获得的测量结果表明，与理想的粘性阻尼器相比，VSD提供了令人满意的多模式阻尼效果，效率系数在30％至50％之间，而较高模式的阻尼则略有下降。还发现这些测量结果与考虑到频率和幅度相关的阻尼器特性的开尔文-沃格阻尼器的浅电缆的复杂模态分析结果一致。尤其，