BRB不同布置高层钢框架BRBF静动力性能分析

Static and dynamic analysis of high⁃rise buckling⁃restrained braced steel frames with different arrangements of buckling⁃restrained braces

以高层钢框架BRBF建筑为研究对象,以BRB不同布置形式为主要研究参量,对高层BRBF建筑进行二阶非线性分析,探讨高层BRBF建筑静动力性能,研究高层BRBF建筑中BRB最优设计方法。(1)从高层BRBF的静态持有性能来看,各高层BRBF建筑满足BRB减震及“强柱弱梁”的抗震设计要求,P-Δ效应对高层BRBF的弹塑性极限承载力和层刚度均有递减作用,忽略P-Δ效应影响会造成高层钢框架设计不安全;高层钢框架增设BRB,可改善P-Δ效应的影响;BRB交错布置的交错型建筑的稳定性好、弹塑性极限承载力值和层刚度值最大。(2)从高层BRBF的动态需求性能来看,高层钢框架增设BRB后各层的层间位移角和层间残余变形明显减小,BRB的塑性耗能占比基本在90%以上,说明BRB作为整体结构的第一道抗震防线,具备良好的耗能减震作用;同时,交错型建筑的减震、耗能效果显著。综上分析,高层钢框架BRBF结构中BRB交错布置方式最优。

The high⁃rise steel frame structures with different arrangements of buckling⁃restrained braces as the main key parameters were designed.The static and dynamic performance of the high⁃rise buckling⁃restrained braced frames(BRBFs)was investigated by second⁃order non⁃linear analysis.Furthermore,an optimal design of buckling⁃restrained braces(BRBs)in high⁃rise BRBFs was proposed.The results are as follows:(1)From the perspective of static reserved performance of the high⁃rise BRBFs,the BRBFs structures with different arrangements of BRBs meet the energy dissipation capacities of BRBs and seismic design requirements of"strong⁃columns and weak⁃beams".A significant restraining effect of the P⁃Δeffect on the high⁃rise BRBFs in terms of elastic⁃plastic ultimate bearing capacity and story stiffness was observed.As a result,without considering the P⁃Δeffect for high⁃rise steel frame structures may result in unsafe seismic design,and adding the BRBs to high⁃rise steel frame structures can reduce the impact of the P⁃Δeffect.In particular,the staggered⁃arrangement of BRBs on BRBFs has better stability,higher layer⁃stiffness and elastic⁃plastic ultimate bearing capacity.(2)From the perspective of dynamic demand performance of high⁃rise BRBFs,the inter⁃story displacement angle and residual deformation of each story were significantly reduced after the high⁃rise steel frame structures with additional BRBs,and the plastic energy dissipation ratio of BRBs is basically more than 90%.Therefore,the BRBs have good energy dissipation and seismic reduction as the first seismic defense line for the overall structure.In addition,the seismic reduction and energy dissipation behavior of the staggered⁃arrangement of BRBs on BRBFs was significant.In summary,the staggered-arrangement of BRBs is recommended as the optimal arrangement of BRBs in high-rise buckling-restrained braced steel frames.