连梁可替换的摇摆钢支撑框架结构抗震性能研究

SEISMIC PERFORMANCE STUDY OF ROCKING STEEL BRACED FRAME WITH REPLACEABLE LINK BEAMS

  • 摘要: 在摇摆钢支撑的柱脚处设置耗能部件,并通过耗能连梁与两侧框架连接形成连梁可替换的摇摆钢支撑框架结构,这种结构具有耗能能力强、耗能部件可替换以及层间变形均匀等优点。为了研究其抗震性能,设计并制作了腹板开单椭圆孔型(LRBF-1)、腹板开菱形孔型(LRBF-2)及不锈钢加劲肋型(LRBF-3)三种耗能连梁形式的摇摆钢支撑框架试件,对试件进行低周往复加载试验,并进行了有限元模拟分析。结果表明:三个试件的滞回曲线均比较饱满,耗能性能优越,同级循环荷载作用下强度基本没有下降。塑性变形集中在耗能部件上,震后可以通过更换耗能部件快速恢复结构使用功能。开单椭圆孔、菱形孔型耗能连梁变形能力良好,耗能性能较好;不锈钢加劲肋型具有更高的极限承载力,刚度下降较缓。耗能部件采用高强度等级的钢材可以增加结构的承载能力和刚度,但过高的钢材强度会使结构的耗能效率低,耗能部件钢材选用应与主体结构相匹配;增加耗能连梁腹板厚度对结构的承载能力、刚度和加载后期耗能效率均有明显提升。

     

    Abstract: Energy dissipation components are arranged at the column base of the rocking steel braced frame, and the frames on both sides are connected through energy-dissipation links to form a rocking steel braced frame structure with replaceable links. This structure has strong energy dissipation capacity, replaceable and uniform deformation between layers, etc. In order to study its seismic performance, three types of links for the rocking steel braced frame which adopts a single oval hole in the web (LRBF-1) and a diamond-shaped hole (LRBF-2), and stainless-steel stiffener type with no hole (LRBF-3) were designed for the low-cycle reversed loading test. The experimental results show that: each specimen has a full hysteresis curve, excellent energy-dissipating performance, and there is basically no decrease in strength under the same level of cyclic load. The damage is concentrated on the energy-dissipating parts, the structural function can be quickly restored by replacing the energy-dissipating parts. The specimens with hole type link have excellent deformation ability and energy-dissipating performance; and the stainless-steel stiffeners type specimen has a higher ultimate bearing capacity and a slower decrease in stiffness. The finite element analysis reveals that using higher-strength steel for energy-dissipating parts can increase the bearing capacity and stiffness, but energy dissipation efficiency of the structure may decrease. Increasing the thickness of link webs can significantly improves the bearing capacity, stiffness and, the energy dissipation efficiency of later loading stage.

     

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