上海光源是一台在建的第三代同步辐射光源，对束流轨道稳定性要求很高。由磁铁和支架组成的支撑组件的机械稳定性是影响束流轨道稳定性的重要因素。对主支撑组件样机的测试结果表明，其最低共振频率处放大倍数为50左右，超过要求5倍。因此，需要研究相应的减振措施。利用阻尼减振原理设计了一种约束阻尼结构。在样机上的测试结果表明，安装该装置后，支撑组件的共振放大倍数最大可以降低91．8%，对应的功率谱密度的峰值可以降低25 dB。因此，该装置可以用来增加支撑的稳定性。

Shanghai synchrotron radiation facility (SSRF) is a third-generation light source under construction. It requires high level of electron beam orbit stability. Mechanical stability of the magnet girder assemblies (MGAs) is essential for electron beam orbit stability. Tests on the SSRF MGA prototype show that its resonant amplification is about 50 at about 19 Hz,which is five times larger than required. Hence vibration damping research for the MGA is necessary,a kind of constrained layer damping plates using viscoelastic materials was developed for attenuating the resonant amplification. The MGA prototype with damping plates had good damping performance in tests,and the resonant amplification was reduced by 91.8%. The damping plates could be used to improve the mechanical stability of the MGA.