转动摩擦-弯曲屈服两级耗能阻尼器疲劳性能

FATIGUE PERFORMANCE OF COMBINED ROTATIONAL-FRICTION AND FLEXURAL-YIELDING METALLIC DAMPERS

  • 摘要: 该文提出了一种转动摩擦-弯曲屈服两级耗能阻尼器,由转动摩擦耗能铰和弯曲屈服耗能槽钢组成的两级耗能构造,适用于连接预制装配式梁柱节点。通过对该新型阻尼器的受力分析研究,揭示了其两级耗能机理,实现了小变形(小、中震)下摩擦耗能铰转动摩擦耗能,大变形(大震、超大震)下耗能槽钢弯曲屈服耗能。设计了单独摩擦耗能铰的摩擦耗能性能以及两级耗能阻尼器整体的低周疲劳试验,两级阻尼器整体的最终疲劳破坏形态为金属耗能槽钢翼缘疲劳破坏。试验结果表明:摩擦耗能铰滞回曲线呈典型摩擦阻尼器的“矩形”滞回,两级阻尼器整体初期的疲劳滞回曲线整体呈饱满的“梭形”,后期随着耗能槽钢的弯曲屈服疲劳破坏,在小位移时滞回曲线呈摩擦阻尼器“矩形”滞回;小变形下摩擦阻尼器的滞回耗能性能稳定,可以达到“小、中震不坏”的抗震要求;大变形(大震)条件下金属阻尼器屈服耗能,最终发生焊缝疲劳破坏。该两级耗能阻尼器能够满足“小、中震不坏,大震可修”的抗震设计目标。

     

    Abstract: This paper proposed a combined rotational-friction (RF) and flexural-yielding metallic (FYM) damper, which can be used for precast beam-column connections. It was a two-stage energy-dissipating structure composed of rotational friction hinge and flexural yielding channel steels. According to theoretical analysis of RF-FYM dampers, the two-stage energy dissipation mechanism was presented. The RF hinge can dissipate energy by rotating friction under small deformation (small and medium earthquake), and the FYM damper yields to dissipate energy under large deformation (rare earthquake or very-rare earthquake). The experiments on energy dissipation capacity of single RF hinge and fatigue performance of RF -FYM damper were carried out. The fatigue failure mode of RF-FYM damper was flexural tensile failure of the channel steels flange. The hysteretic curve of the RF hinge exhibited a typical 'rectangular' shape. As for the RF-YFM damper, the fatigue hysteresis curve exhibited 'spindle' shape at the initial stage and flexural yielding occurred in channel steels. It can be concluded that the hysteretic energy dissipation performance of the friction damper is stable under small deformation, and can meet the seismic requirements of "no damage under small and medium earthquakes"; Under large deformation (rare earthquake), the FYM damper yields and consumes energy, eventually causing weld fatigue failure. This RF-FYM damper can meet the seismic design goal of "no damage under small and medium earthquakes, and repairable under large earthquakes".

     

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