开长孔式叠层钢管屈曲约束支撑试验研究

Experimental study on performance of a buckling-restrained brace consisting of three steel tubes with slotted holes in the middle tube

设计一种开长孔式叠层钢管屈曲约束支撑，该种屈曲约束支撑采用三种不同尺寸的Q235钢管型材进行组合，并对承受轴力的芯材钢管进行开长孔削弱；通过对5个试件进行轴向低周往复加载试验，研究了不同开孔率，开孔数量对其承载力，变形性能，滞回耗能性能，骨架曲线以及破坏形态的影响。研究结果表明：此种开长孔式叠层钢管屈曲约束支撑的构造合理，在开孔率合理的情况下，支撑变形能力强，低周疲劳性能好，滞回曲线饱满，可以提供30％～42％的附加等效阻尼比。

A novel buckling-restrained brace was proposed. The buckling-restrained brace consists of three Q235 steel tubes with different diameters. The three tubes are overlapped, and the smallest tube and the largest tube can restrain the out-of-plane deformation of the tube in between. Slotted holes are arranged at the middle tube. Cyclic loading tests on five specimens were conducted to investigate the strength, the deformation capacity, the hysteretic energy dissipation performance, the skeleton curve, and the failure mode of the buckling-restrained brace. Size and number of the slotted holes for the reduced tube section were chosen as test parameters. The test results suggest that the structure of the novel buckling-restrained brace is reasonable. With appropriate arrangement of the slotted holes, the buckling-restrained brace exhibits excellent performances in terms of deformation capacity and low-cycle fatigue behavior, and the hysteresis curves of the brace are stable and saturated, which may provide additional equivalent damping ratio of 30% -42%.