扇形铅黏弹性阻尼器加固RC框架的抗震性能试验研究

Experimental study on seismic performance of RC frame retrofitted with sector lead viscoelastic dampers

针对钢筋混凝土框架结构梁柱节点震害严重的抗震问题,提出采用扇形铅黏弹性阻尼器加固框架结构的方法,结合扇形阻尼器型式提出外包箱形钢板和外包U形钢板两种不同的加固连接方式。为研究扇形铅黏弹性阻尼器加固框架的抗震性能,设计并制作了3榀框架试件,分别为空框架和两榀不同连接的扇形铅黏弹性阻尼器加固框架,通过低周反复加载试验分析了其滞回性能、承载能力、刚度退化、耗能能力等参数。试验结果表明:采用扇形铅黏弹性阻尼器加固的框架滞回曲线饱满、耗能能力强、加固效果良好;扇形铅黏弹性阻尼器为框架提供了一定的抗侧刚度,提高了框架的水平承载能力,延缓了框架塑性铰的产生,使框架具有良好的耗能能力;外包U形钢板和外包箱形钢板用于扇形铅黏弹性阻尼器与主体结构的连接都是有效的,这两种不同的连接方式对加固框架的整体抗震性能影响不大。

According to the seismic problem that beam-column joints of reinforced concrete （RC） frame may be severely damaged in earthquakes, a new strategy of using sector lead viscoelastic dampers （SLVD） to retrofit RC frame structures was proposed. Two retrofitting approaches using encased box-type steel plates and U-shaped steel plates to combine with SLVD were presented. To study their seismic performance, three RC frame specimens, including one untreated frame and two retrofitted frame with SLVD （i. e. using above two different connections ）, were designed and fabricated. Furthermore, these three specimens were tested under the low-cycle repeated loading for the hysteretic behavior, bearing capacity, stiffness degradation, and energy dissipation capacity, etc. The experimental results show that： （a） the frames retrofitted with SLVD have full hysteretic curves and good energy dissipation capacity, indicating the good retrofitting perforulance of SLVD; （b） SLVD may provide certain additional lateral stiffness for the retrofitted frame, so that the horizontal bearing capacity of frame can be enhanced, and the energy dissipation capacity of frame ean be strengthened due to the delay of occurrence of plastic hinges ; （c） both the encased U-shaped steel plates and box-type steel plates are effective for the connections between SLVD and major structure, but the two different connections may have slight effects on seismic performance of retrofitted frames.