不同间隙全钢圆套圆防屈曲支撑的抗震性能研究

RESEARCH ON SEISMIC BEHAVIOR OF STEEL TUBE-IN-TUBE BUCKLING-RESTRAINED BRACE WITH DIFFERENT GAP VALUES

支撑-框架体系在设防烈度和罕遇地震作用下其传统支撑易较早发生受拉、受压屈服,甚至发生大幅值屈曲失稳破坏,不利于框架结构的承载和能量耗散。全钢圆套圆型防屈曲支撑(称圆套圆防屈曲支撑)可代替传统支撑为支撑-框架体系提高承载能力和耗能能力。该圆套圆防屈曲支撑主要是由承力耗能内圆管(称核心管)与约束核心管屈曲变形的外圆管(称约束外管)构成的一种特殊耗能支撑。利用静力非线性分析方法对不同间隙的圆套圆防屈曲支撑力学性能进行分析,包括滞回曲线、抗震性能指标CPE、骨架曲线以及刚度退化等。结果表明:间隙取值为2mm时,圆套圆防屈曲支撑比传统支撑受压承载能力提高了55.4%,滞回耗能提高了80.2%,抗压刚度提高了111%。圆套圆防屈曲支撑显著改善了传统支撑受压易屈曲的缺点,且在受力性能、滞回耗能、造价以及制作工艺等各方面表现优异。

Under the moderate and rare earthquakes,the support-frame system is easy to be subjected to tension and compression at an early stage,and large-scale buckling instability may occur.It is harmful to the bearing capacity and energy dissipation of the frame structure.The steel circular tube-in-tube buckling-restrained brace(called tube-in-tube buckling-restrained brace)studied in the paper can replace the traditional support as the support-frame system to improve the bearing capacity and energy consumption.The tube-in-tube buckling-restrained brace is mainly composed of the energyconsuming inner tube(called the core tube)and the outer tube that restrains the buckling deformation of the core tube(called the constrained outer tube)constitutes a special energy-consuming support.In the paper,the static nonlinear analysis method was used to analyze the mechanical properties of tube-in-tube buckling-restrained brace with different gap values.The analysis included hysteresis curves,seismic performance indicators CPE,skeleton curves,and stiffness degradation.The research showed that when the gap value was 2 mm,the tube-in-tube buckling-restrained brace was improved by 55.4%compared with the traditional support,the hysteresis energy was increased by 80.2%,and the compressive stiffness was increased by 111%.The tube-in-tube buckling-restrained brace could significantly improve the traditional support,which was easy to occur buckling when it was compressed.The results showed that the tube-in-tube buckling-restrained brace was excellent in various aspects such as mechanical properties,hysteretic energy consumption,cost and production process.