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提出一种H型钢防屈曲支撑(HBRB)以便于对结构中既有H型钢构件进行抗震加固,同时可避免传统H型钢防屈曲支撑中过早发生内芯局部屈曲破坏的现象发生。该支撑的耗能内芯采用H型钢,约束构件由2个U形钢和2块钢板通过高强螺栓拼接而成。为了研究HBRB的抗震性能,对3个试件进行拟静力试验,结果表明,构造合理的HBRB具有稳定的滞回耗能能力。通过分析试件破坏模式发现:将端部加劲肋布置在翼缘两侧有利于避免H型钢防屈曲支撑内芯应变集中及约束构件局部鼓曲破坏的发生;端部加劲肋和外部约束构件之间的间隙过大会导致加劲肋和H型钢内芯焊缝撕裂;采用低电流、多道焊缝施焊有利于提高防屈曲支撑的疲劳性能。在轴向荷载作用下,H型钢内芯除了发生整体弯曲变形外,腹板和翼缘作为板件还会分别发生自身的高阶屈曲;翼缘和腹板在屈曲后与约束构件接触,相当于对H型钢增加额外的侧向约束,使其整体稳定承载力明显提升。
In this paper, an anti-buckling brace (HBRB) of H-section steel is proposed to improve the seismic resistance of both existing H-section structural members and avoid the premature buckling of the inner core in the buckling brace of conventional H-section steel. The supported energy-consuming core adopts H-shaped steel, and the restraining member is formed by splicing two U-shaped steel plates and two steel plates with high-strength bolts. In order to study the aseismic performance of HBRB, three specimens were subjected to quasi-static test. The results show that the well-structured HBRB has a stable ability of hysteresis. It is found through the analysis of specimen failure modes that the arrangement of the end stiffeners on both sides of the flange helps to avoid the strain concentration of the H-beam buckling-supported core and the local drum buckling failure of the restraining member. The end stiffeners and external restraining members Between the gap is too large led to the stiffener and H-shaped steel core weld tear; the use of low-current, multi-seam welding is conducive to improving the anti-buckling support fatigue performance. Under the action of axial load, in addition to the overall bending deformation of the H-shaped steel core, the webs and flanges as a plate also have their own higher-order buckling respectively; the flanges and webs contact the restraining members after buckling, In the H-beam additional lateral constraints, so that the overall stability of the bearing capacity increased significantly.