PBL加劲型矩形钢管混凝土不等宽T型节点受拉性能

Tensile behavior of PBL stiffened concrete-filled rectangular steel tubular unequal T-connections

PBL加劲肋兼有加劲肋和剪力连接件的双重优势,T型节点主管采用PBL加劲型矩形钢管混凝土是一种新型钢-混组合结构,探明其破坏模式和承载力水平具有重要意义。基于矩形钢管混凝土T型节点受拉试验,设计了主管为PBL加劲型矩形钢管混凝土,支管为方钢管的不等宽T型节点受拉试件,其中,主管钢管宽厚比为27、支主管宽度比为0.4;通过非线性有限元数值模拟,从破坏模式、节点承载力、抗拉刚度及应力分布等方面分析PBL加劲肋对矩形钢管混凝土不等宽T型节点受拉力学性能的影响。研究结果表明:PBL加劲肋兼有加劲肋和剪力连接件的双重作用,可有效限制顶板被掀起,提高节点顶板面外抗弯承载力和抵抗局部变形的能力;能够明显改善不等宽T型节点的抗拉性能和抗疲劳性能,显著提高节点的抗拉刚度和节点承载力。

PBL stiffener had the dual advantages of stiffening rib and shear connector. T type joint using PBL stiffened rectangular concrete-filled steel tube was a new type of composite structure. It had important significance to research its failure modes and bearing capacity. Based on concrete-filled T-connections tensile test results, it designed PBL stiffened concrete-filled unequal width T-joint which chord slenderness ratio was 27 and branch-to-chord width ratio was 0.4. In contrast, it included the empty T-joint and concrete-filled T-joint. According to nonlinear finite element numerical simulation, it analyzed failure mode, bearing capacity, tensile rigidity and stress distribution of unequal width T-joint influenced by PBL stiffener. The results show that PBL stiffener could sharply improve tensile and fatigue performance and greatly improve tensile stiffness and bearing capacity of unequal width T-joint. 3 tabs, 14 figs, 15 refs.