采用碳纤维包裹约束的装配式防屈曲支撑试验

Experimental study on assembled buckling-restrained braces wrapped with carbon fiber

为方便装配式防屈曲支撑拆解修复和提高抗腐蚀能力,提出了采用碳纤维包裹约束的新型装配式防屈曲支撑.一方面,通过剖开纤维材料分离外包约束构件来替换受损内核单元可实现构件震后的快速修复,另一方面,碳纤维布作为外包材料解决了外包钢管耐腐蚀性差的问题.通过4个新型防屈曲支撑构件在往复荷载作用下的拟静力试验,研究了防屈曲支撑在不同加载制度下,不同约束比下的性能.试验结果表明:在循环变形过程中试件基本没有发生刚度与强度的退化,且延性与耗能能力都很好.碳纤维布成功地起到连接装配式防屈曲支撑两部分外包约束单元的作用,并可有效抵抗来自内核单元施加的侧向推力.采用碳纤维包裹约束的新型防屈曲支撑受压时,内核单元会产生多波屈曲现象,使得约束单元中的包裹材料发生变形,最终使得构件的滞回曲线表现为力的"跳动",多波屈曲现象更为显著试件的滞回耗能能力略差.新型装配式防屈曲支撑具有良好的滞回性能,为防屈曲支撑实现可装配式提供了新途径.

The assembled bucking-restrained b the repairability and corrosion resistance. The races （BRB） wrapped with carbon fiber were proposed to improve damaged inner core element can be replaced by cutting the fiber material to make the outer restrained components separated, which makes the inner core to be replaced easily after earthquake, and the proposed assembled BRB can also improve the corrosion resistance of outer steel tube. Four assembled BRB specimens were tested by quasi-static tests, and different loading schedules and constraint ratios were considered. The results show that new assembled BRBs could undergo fully-reversed axial yielding cycles nearly without loss of stiffness and strength, and the ductility and energy absorption capacity are large enough. The carbon fiber cloth successfully connects outer confined elements and effectively resists the lateral thrust exerted by inner core. Multi-wave buckling phenomenon occured in the inner core element, and deformation appeared in wrapped material under compression load. The hysteretic curves of BRBs ＂jump＂ in the compression stage. The hysteretic behavior and energy dissipation capacity of BRBs get worse with more obvious multi-wave buckling. The new assembled BRB has good hysteretic behavior and provides a new way to realize assembling of BRBs.