摇摆桁架-BRB-钢框架体系地震失效模式与抗震性能分析

Seismic failure modes and seismic behavior analysis of rocking truss-BRB-steel frame systems

  • 摘要: 建筑结构抗震设计所希望的结构地震失效模式是完全梁铰式失效,由于各种不确定性的存在,在实际地震中,结构是否能发生完全梁铰式失效是无法预知的。而防屈曲支撑构件(BRB)延性较大,在地震作用下可稳定地耗散地震输入结构的能量。鉴于此该文提出了一种摇摆桁架-BRB-钢框架体系,采用静力推覆分析方法,识别出了结构的主要地震失效模式,对其失效路径以进行了分析;对传统钢框架结构、摇摆桁架-钢框架体系、摇摆桁架-BRB-钢框架体系在小震、中震、大震作用下进行时程分析,并基于峰值层间位移角评价了三种结构的抗震性能。结果表明摇摆桁架-BRB-钢框架体系,在结构耗能减震、失效模式的优化控制,降低结构的残余变形等方面均起到了重要作用,新结构的侧向变形较传统钢框架结构更加均匀,结构整体参与耗能的能力更强。

     

    Abstract: The seismic failure mode of seismic design of building structures is the failure of full beam hinges. In reality, it is difficult to foresee the full beam hinge failure mode of the structure due to uncertainties. Owing to large ductility, Buckling-Restrained Braces (BRBs) can dissipate the energy impacted on structures subject to earthquakes. In view of this feature, a rocking truss-BRB-steel frame system is proposed in this study. The main failure modes of the structure were identified by the pushover analysis and its failure path was analyzed. Based on the time history analysis for cases of earthquakes with mild, moderate and severe intensities, peak story drifts and seismic performance of a conventional steel frame structure, a rocking truss-steel frame system and a rocking truss-BRB-steel frame system were compared and analyzed. The results showed that the rocking truss-BRB-steel frame system played an important role in the structural energy dissipation, the optimal control of the failure modes, and the reduction of the residual deformation of the structures. The lateral deformation of the rocking truss-BRB-steel frame system was more uniform than that of the traditional steel frame structure and the energy consumption of the whole-parts-structure was stronger.

     

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