防屈曲支撑钢框架基于延性的抗震性能设计

SEISMIC PERFORMANCE-BASED DESIGN BASED ON DUCTILITY OF BUCKLING-RESTRAINED BRACED STEEL FRAME

防屈曲支撑滞回曲线稳定饱满,耗能能力强,可以为结构提供较大的附加阻尼,在进行抗震设计时要予以充分考虑。传统的基于弹塑性层间位移角限值的抗震性能设计往往会高估结构总的有效阻尼比,使设计偏于不安全,因此该文以我国抗震规范弹性反应谱为基础,提出了一种基于延性的抗震性能设计方法,最后通过增加支撑构件和调整支撑的类型或截面的方法完成结构设计,使其满足抗震性能目标的要求。

The Bucking-Restrained Braces（BRBs） can undergo fully-reversed axial yield cycles without loss of stiffness and strength,whose seismic energy dissipation ability is superior.The additive damping ratio that BRBs impart to the structure is large,which must be considered in seismic performance design.The conventional seismic performance design is based on elasto-plastic inter-story displacement angle,the structure will possibly be unsafe because the total equivalent damping ratio of the structure is usually overrated.Based on the elastic demand spectrum and elasto-plastic demand spectrum which were established with elastic response spectrum in Chinese code for seismic design of buildings（GB50011-2001）,a seismic performance design method based on ductility was put forward.In the design method,to meet the seismic performance objective,the braces will be installed,the section area of braces will be rectified or the common steel braces will be replaced by buckling-restrained braces.