【作者】 张冬芳；

【导师】 赵均海；

【作者基本信息】 长安大学 ， 结构工程， 2011， 硕士

【摘要】 由于钢管混凝土结构具有承载力高,塑性、韧性好,还具有很好的耐火安全性,良好的抗震性能等优点,在国内外迅速发展,应用前景广泛。但是,对钢管混凝土节点的力学性能的研究还比较有限,虽然已经进行了大量的试验研究,但对节点受力性能的理论分析还不够深入,况且,国内外对钢管混凝土柱节点的研究,主要集中于钢管混凝土柱-钢梁节点,而对钢管混凝土柱-钢筋混凝土梁节点的研究还比较少,没有形成完整的理论。综合我国现状及目前钢管混凝土柱节点的研究成果,本文对复式钢管混凝土外钢管不连通环梁节点进行研究,主要工作内容如下：(1)复式钢管混凝土外钢管不连通环梁节点的连接形式,即复式钢管柱的外钢管在节点处断开,钢筋混凝土梁纵筋直接插入节点核心区,使用环梁加大节点区来补偿外钢管断开的影响。本文对四个节点试件进行了拟静力试验研究及有限元模拟。(2)对节点试件进行低周往复荷载作用下的试验研究,通过对其破坏形态和破坏机理的分析知,环梁处形成塑性铰,属于延性破坏；得到节点的P-△滞回曲线、节点弯矩-梁柱相对转角关系、最终承载力和骨架曲线,并建立了该新型外钢管不连通钢筋混凝土环梁节点的恢复力模型。(3)采用有限元软件ANSYS对节点模型进行数值模拟。模拟滞回曲线与试验滞回曲线吻合较好,并进行拓展分析,得到节点区竖筋的锚固长度、节点区(包括环梁)的混凝土强度、框架梁的混凝土强度及其纵筋配筋率等因素对节点骨架曲线影响的一般规律。更多还原

【Abstract】 Concrete filled steel tube (CFST) structures are widely used in many countries due to its high bearing capacity, good ductility, high toughness, fire resistance, and good seismic performance. However, the researches on the mechanical properties for the connections of CFST are still relatively limited. Although a large number of experimental studies have been carried out, and the theoretical analysis of mechanical properties for the connections are still not deep enough. The researches for the connections of CFST mainly focused on connections with steel beams. However, the investigations for connections with reinforced concrete (RC) beams are very few.In this paper, the advances of the connections of CFST have been reviewed firstly. And the behavior of a new type of the connections for Multibarrel tube-confined concrete column with RC ring beam has been studied, the main content includes:(1)The new type of connections for the Multibarrel CFST column and RC ring beam is that the outer tube of the Multibarrel CFST disconnected in the connections, the longitudinal reinforcement of RC beam inserted directly into the nodes. In this paper, the pseudo-static tests on four connections have been carried out. The FEM models have been established and the behaviors of connections have been numerical simulated.(2)The behaviors of connections under low cyclic loadings have been investigated in this paper. The failure patterns and the failure mechanism have been analysed. The plastic hinges were formed at the ring beams and the failure of the test specimens is ductile. The hysteretic curves of load-displacement, the relationship between moment and relative angle of the beams and the columns, the ultimate bearing capacity and the skeleton curves are obtained in this paper. And the restoring force model for the new type connections of RC ring beams with the discontinuous outer Tubes is finally established.(3)The software ANSYS of finite element was used to simulate the behavior of connections. The simulated hysteretic curves were compared with experimental data and good agreement can be observed. Moreover, parametric studied have been carried out to investigate the influences of anchorage length of vertical steel bars for the nodes area, the strength of the concrete for the nodes area, the concrete strength of the frame beam, and the longitudinal reinforcement ratio of the frame beam on the skeleton curves.更多还原