内隔板式与隔板贯通式方钢管混凝土柱-H形钢梁节点抗连续倒塌性能对比

Comparison of progressive collapse behavior between inner-diaphragm stiffened and through-diaphragm stiffened concrete filled SHS column-H beam joints

以2种方钢管混凝土柱-H形钢梁栓焊连接刚性节点为研究对象,通过静力试验和数值模拟考察梁柱节点在结构连续性倒塌条件下的受力性能,并对比内隔板与贯通式隔板两种柱横向加劲板形式对节点子结构抗力机制发展以及承载能力的影响。结果显示,节点初始破坏均位于梁下翼缘的连接截面。节点子结构在加载前期主要通过弯曲机制提供竖向抗力,在加载后期逐渐转变为依靠悬链机制抵抗上部荷载。相比于内隔板构造,贯通式隔板构造使梁下翼缘更容易产生断裂,梁下翼缘断裂所对应节点子结构变形大小主要对弯曲机制的发展产生影响,进而影响到节点子结构所能承担的最大动荷载。

This research investigated the behavior of two types of rigid concrete filled SHS column-H beam joint with welded flange-bolted web connection in resisting structural progressive collapse by means of full-scale static test and numerical simulation. One assembly adopted an internal-diaphragm transverse column stiffener and the other used a through-diaphragm transverse column stiffener. Comparison was made to obtain the influence of the column stiffener types on the development of vertical load resisting mechanism and vertical carrying capacity of the joint assemblies.The results indicate that the initial failures occur at connecting zone of the bottom beam flanges. The joint assemblies resist the vertical load by flexural mechanism at the beginning,and the dominant vertical load resisting mechanism shifts to catenary mechanism with the increasing deformation. The bottom beam flange of the assembly with throughdiaphragm is more likely to fracture than that with internal-diaphragm. The corresponding deformation of the joint assemblies mainly has an effect on the development of their flexural mechanism and further influences the maximum dynamic loads that can carried by the joint assemblies.