位移放大型黏滞阻尼伸臂桁架减震效果及动力试验研究

为提高黏滞阻尼伸臂桁架在地震作用下的耗能效率，设计了一种带位移放大装置的黏滞阻尼伸臂桁架。对分别设置传统型和位移放大型黏滞阻尼伸臂桁架的超高层结构进行有限元分析，对比了结构的地震响应及阻尼器的工作状态。通过动力荷载试验，考察两种黏滞阻尼伸臂桁架的滞回性能，对比阻尼器的位移及耗能，研究位移放大系数的变化规律，分析伸臂桁架刚度对黏滞阻尼伸臂桁架工作效率的影响。结果表明：相比传统型黏滞阻尼伸臂桁架，采用位移放大型黏滞阻尼伸臂桁架可将阻尼器的耗能效率提高至原来的1.5~1.8倍，使结构获得更好的减震效果；位移放大型黏滞阻尼伸臂桁架滞回曲线光滑、对称、饱满，具有良好的工作性能，且能有效放大阻尼器的工作位移并增大耗能；提出了黏滞阻尼伸臂桁架的位移放大系数的计算式，计算值与试验值吻合较好；为保证黏滞阻尼伸臂桁架的工作效率，建议伸臂桁架的刚度比取值不小于9。

Seismic mitigation effect and dynamic test study of displacement-amplified viscously-damped outrigger

An innovative viscously-damped outrigger was designed with the amplifying device to improve its energy dissipation efficiency under earthquake action. The conventional and amplified viscously-damped outriggers were compared in terms of the working condition of dampers and seismic mitigation effect of the structural response by finite element analysis. The two types of viscously-damped outriggers were tested to examine their hysteretic properties by dynamic cyclic loading tests. The displacement and energy dissipation of the dampers in different types of viscously-damped outriggers were compared, and the variation law of the displacement amplification factor was studied. Besides, the effect of outrigger stiffness on the working efficiency of viscously-damped outriggers was analyzed. The results show that the working efficiency of dampers can be improved by 50% to 80% times after upgrading the conventional viscously-damped outrigger to the amplified viscously-damped outrigger, which improves the damping effect on the structure. The hysteretic curves of the amplified viscously-damped outrigger are smooth, symmetrical and full, indicating that it has a good working performance and can effectively amplify the working displacement and energy dissipation of the damper. The theoretical formula for calculating the displacement amplification factor was proposed, and the calculated results were in good agreement with the experimental results. It is recommended that the stiffness ratio of outriggers be not less than 9 to ensure the working efficiency of viscously-damped outriggers.