提高异形柱框架节点抗震性能的试验研究

Experimental research on seismic behavior of joints of specially shaped columns

为了解决异形柱结构节点的薄弱问题,对异形柱框架节点核心区应用X形配筋增强、聚丙烯纤维增强及钢纤维增强的异形柱节点与同条件下未增强的异形柱节点进行拟静力试验研究,对比3种方法增强的异形柱框架节点试件的破坏特征、承载能力和位移延性、滞回曲线、刚度退化、耗能能力和累积损伤等抗震性能指标.研究结果表明:与未被增强的异形柱节点相比,X形配筋增强、聚丙烯纤维增强或钢纤维增强的异形柱节点抗震性能显著提高.在异形柱节点核心区加入X形配筋、掺入聚丙烯纤维或钢纤维均能提高节点的承载能力和变性能力,改善节点滞回特性,减缓节点的累积损伤程度.在节点核心区加入X形配筋比纤维增强的异形柱框架节点在提高节点的承载能力,减轻节点累积损伤程度方面效果更显著.

In efforts to solve the issues of weak part of joints of specially shaped columns, a study testing under low cyclic loading used for the joint of specially shaped columns reinforced by X-shaped reinforcement, polypropylene fiber and steel fiber reinforcement in the core zone of joints, and the joint of specially shaped column without rein- forcement under the same condition was conducted. A comparison was performed for these three kinds of reinforce- ment in such seismic performance indices as the damage characteristic, bearing capacity, displacement ductility, hysteretic curve, rigidity degradation, energy dissipation and cumulated damage. It was revealed that, comparing with the joint of specially shaped column without reinforcement, the seismic behaviors of the joints of specially shaped column reinforced by X-shaped reinforcement, polypropylene fiber or steel fiber were obviously improved. The beating capacity and deformation capacity of joint reinforced by X-shaped reinforcement, polypropylene fiber or steel fiber in core zone was enhanced, and simultaneously the hysteretic characteristic was improved significantly and the degree of cumulated damage was lightened. Besides, the beating reinforcement in core zone was higher and the degree of cumulated damag capacity of a joint reinforced by X-shaped e was lighter than that reinforced by fiber.