基于反应谱的附加阻尼比计算方法及工程应用

Additional damping ratio calculation method based on response spectrum and engineering application

随着消能减震技术的发展和应用,采用阻尼器产品的工程项目迅速增多,其中有较大比例的项目采用的是位移型金属阻尼器。采用这类阻尼器时需要计算结构小震附加阻尼比,目前《消能减震技术规程》(JGJ 297—2013)中建议计算小震附加阻尼比的方法有两种:时程分析法和基于反应谱的线性迭代法,这两类方法在实际应用时相对比较复杂。例如:采用时程分析法时需要选取多条地震波进行分析,选波和计算都比较繁琐;线性迭代法则需要进行多次迭代,并且每个模型中阻尼器的等代截面需要不断调整,工作量大,效率低。提出了一种新的基于反应谱的附加阻尼比计算思路,可称之为"放大刚度法",整个分析过程只需在一个分析模型中调整即可算出结构相应的附加阻尼比,方便可靠。该方法特别适用于方案设计阶段以快速确定阻尼器的参数和附加阻尼比的大小,减小设计方案的周期。本文还对一个实际工程项目用该方法进行阻尼比的计算和阻尼器参数确定,并且用时程分析法进行复核,验证了该方法的可靠性。

With the development and application of energy dissipation technology, the number of projects using dampers increase rapidly. There is a large proportion of the dampers are the metal dampers. It＇s necessary to calculate the additional damping ratio when using this kind of damper. At present, there are two kinds of methods proposed in the Technical Specification for Building with Energy Dissipation Devices （ JGJ 297--2013）： time history analysis method and linear iterative method based on response spectrum. These two kinds of methods are relatively complicated in practical application, for example： multi seismic waves are needed in time history analysis method, seismic waves selection and calculation are more complex. The linear iterative method needs many iterations, and the equivalent element of the damper in each model needs to be adjusted. This method is heavy workload and low efficient. A new calculation method of additional damping ratio based on response spectrum was proposed, it can he called ＂ amplification stiffness method＂. In the whole analysis process, the additional damping ratio of the structure can be calculated only by adjusting one model, it＇s more convenient and reliable. The method is especially suitable for the design phase to determine the parameters of the damper and the additional damping ratio,it can reduce the design cycle. The damping ratio was calculated and the damper parameters were determined by this method in a practical project, and checked by the time history analysis method, the reliability of the method was verified.