柱脚可抬起的连柱钢支撑结构抗震性能研究

Study on Seismic Performance of Linked Column Steel Braced Frame With Lifting Column Base

为研究连柱钢支撑结构的抗震性能,提出了中柱采用可抬起柱脚的连柱钢支撑结构体系,并给出了可抬起柱脚的典型构造。设计了2个中柱柱脚采用不同形式和2组高跨比不同的连柱钢支撑结构体系。采用ABAQUS有限元分析软件对试件进行循环加载,对比分析了结构的滞回曲线、破坏机理、以及塑性耗能分布等方面的特征。利用等能量原理将试件的正向骨架曲线简化为三折线模型,研究高跨比变化对耗能段可替换层间位移角范围的影响。研究结果表明:柱脚可抬起的连柱钢支撑结构体系与普通刚接连柱钢支撑结构体系相比,其破坏模式更为理想、耗能机制更加合理、延性以及耗能能力更好。结构跨度增大,耗能段替换层间位移角范围的上限随之增大;层高增大,耗能段可替换层间位移角范围的上限和下限都随之减小。

In order to research the seismic performance of linked column steel braced frame, a type of linked column steel braced frame with middle column using lifting column base is proposed and the typical structure of the column base is presented. Two specimens with middle column base in different forms and two series of specimens with different high-span ratios of structure are designed. Finite element analysis software ABAQUS is used to conduct a cyclic loading on these specimens, the hysteretic curve, failure mechanism and the plastic energy dissipation distribution are compared and analyzed. The positive skeleton curves are simplified to the trilinear model according to the principle of equal energy to study the effect of the high-span ratios variation on the replacement range of link. The research results show that：compared with linked column steel braced frame with rigid column base, the linked column steel braced frame with lifting column base has more ideal failure mode, more reasonable energy dissipation mechanism and better ductility and energy dissipation capacity. As the span increases, the upper limit of the replacement range of the link will be increased. As the story increases, the upper and lower limits of the replacement range of the link will be decreased.