将预应力索支撑引入多高层钢结构,提出耗能预应力索支撑-框架结构,该结构体系能有效提高框架结构的抗侧能力和侧移延性,减小柱子计算长度,降低结构用钢量。利用有限元分析方法,分别对预应力索支撑-刚接框架、预应力索支撑-半刚接框架以及纯刚接框架进行静力性能分析,研究轴压比对三者的弹塑性发展、极限承载力、破坏机理、侧移刚度和侧移延性等方面的影响规律。研究表明,设置索支撑除增大框架抗侧刚度和提高极限承载力外,更重要的是提高侧移延性,改善破坏模式,且当外荷载去除或减小时使框架全部或者部分回到原始平衡位置,实现自复位。另外,随着轴压比的增大,三者抗侧承载力均降低,纯框架侧移延性降低,但索支撑-框架延性基本不受轴压比影响。
A new type of prestressed cable-braced energy-dissipation frame structure was proposed by adding prestressed cable brace to a high-rise building.This structure could improve lateral resistance and ductility of steel frame effectively, thus resulting in smaller calculation length of columns and less steel-consumption.By using finite element method, the static behavior of cable-braced rigid frame, cable-braced semi-rigid frame and steel frame was analyzed, and the influence law of axial compression ratio on their elastioplasticity behavior, ultimate bearing capacity, failure mechanism, lateral stiffness and ductility etc was studied.The results showed that cable brace could improve the lateral stiffness and bearing capacity of steel frame, more importantly, could also improve its lateral ductility, change failure model, and produce the self-centering function by tensioning frame back to the original location entirely or partly when the load was removed.In addition, with the increase of axial compression ratio, bearing capacities of the three type frames were all decreased, and the ductility of steel frame was also reduced. However, the ductility of cable-braced steel frame was not influenced by the axial compression ratio.