台湾某钢框架大楼采用阻尼器补强结构减震效果评析

阻尼器是一种效果良好的减震装置,将阻尼器安装于结构中能够适时为结构体系提供阻尼力,从而减小地震作用对结构的破坏。黏滞阻尼器对振动的反应比较敏感,在结构受到较小振动时就可以发挥其减震效果,其阻尼力会随着振动周期和使用状态温度的不同而变化。当地震发生时,安装在结构中的阻尼器会消减地震作用,降低传导到主结构体系的地震能量,减小结构相对位移。本文介绍了黏滞阻尼器的工作原理和安装有黏滞阻尼器的结构体系的阻尼比的计算方法,对减震结构的减震效果的评析方法做出探讨,并以一安装有黏滞阻尼器的台湾某既有钢框架结构为例,分析了(1)该结构在遭受地震作用时的地震反应;(2)该结构体系在不同地震作用水平时的阻尼比,包括主体结构阻尼比和黏滞阻尼器阻尼比;(3)结构安装黏滞阻尼器后的减震效果。实例对本文的减震评析方法和减震效果进行了说明和分析,计算及分析结果表明利用黏滞阻尼器加固既有结构能够取得较好的减震效果,本文所提减震效果评析方法是一种实用有效的评析方法,对类似工程的减震评析具有一定的参考价值。

Analysis and evaluation of seismic mitigation effect on a steel frame building strengthened by dampers in Taiwan

Damper is a remarkable kind of vibration control device,which can be installed into a structures to provide damping force at a suitable time,and thus reduce the damage to structure caused by the earthquake action.Fluid viscous damper is sensitive to the vibration response;its damping force can change along with the vibration period and the temperature of service state,and has vibration mitigation effect when the structure is exposed to minor vibration.When earthquake happens,the dampers installed in structure will mitigate the seismic action;reduce the seismic energy introduced into the main structure system,and decrease the structural relative displacement.Working principle of fluid viscous damper is introduced in this paper,as well as the calculation method for the damping ratio of the structure system with fluid viscous dampers.Also,a method to evaluate the vibration control effect is discussed.Further more,taking an existing steel frame structure in Taiwan installed with fluid viscous dampers for example,three aspects of research are done,including(1) seismic responses of the structure under earthquake action,(2) damping ratio of the structure system under different seismic action levels,which concludes the main structural damping ratio and the damping ratio of fluid viscous dampers,(3) vibration mitigation effect after installing fluid viscous dampers.The evaluation method and vibration mitigation effect is well illustrated by this example.And the results of calculation and analysis show that retrofitting with fluid viscous dampers can produce apparent vibration control effect,and the vibration mitigation evaluation method put forward in this paper is useful and effective with certain reference value to similar engineerings.