新型外包加强型节点抗震性能试验研究

Experimental study on seismic performance of new type of outsourced enhanced joint

为了减小钢筋混凝土(RC)框架-轻钢增层混合结构的鞭梢效应,本文提出了一种用于该类结构的新型外包加强型节点,旨在加强对上部结构的约束,减小上下部结构的刚度突变。为了深入研究其抗震性能,与另一种外包锚固式节点进行了低周往复荷载作用下的对比性试验研究。结果表明:两种节点均表现为梁端塑性铰破坏,并能有效控制裂缝开展;新型外包加强型节点滞回曲线饱满,捏拢速度较慢,并能将塑性铰外移,有效保护了节点核心区,其刚度退化、等效黏滞阻尼系数、耗能能力等各项指标都较外包锚固式节点有不同程度的提升,提高了节点的承载力和刚度,具有更好的抗震性能。本文的研究可以为轻钢增层混合结构的推广应用提供科学依据和技术支持。

In order to reduce the whipping effect of the reinforced concrete(RC) frame-lightweight steel mixed structure, a new type of outsourced enhanced joint used for this kind of structure is proposed in this paper, which aims to strengthen the constraint on the upper structure, and reduce the stiffness mutation of the upper and lower structure. In order to study its seismic performance in depth, a comparative experimental study under low cycle reciprocating load was carried out with another outsourced anchored joint. The results show that the both kinds of joints are all characterized by plastic hinge failure of the beam end, and can effectively control the development of crack. The hysteretic curve of the new type of outsourced enhanced joint is full, the pinching speed is slow, and the plastic hinge can be moved outward, the core area of the joint is effectively protected, the stiffness degradation, equivalent viscous damping coefficient, energy dissipation capacity and other indicators are improved to different degrees than the outsourced anchored joint, which improves the bearing capacity and stiffness of the joint, and has better seismic performance. The research in this paper can provide scientific basis and technical support for the popularization and application of lightweight steel mixed structure.