Seismic Behavior of Diaphragm-Through Connections of Concrete-Filled Square Steel Tubular Columns and H-Shaped Steel Beams

Based on the introductions of a type of diaphragm-through connection between concrete-filled square steel tubular columns (CFSSTCs) and H-shaped steel beams,a finite element model of the connection is developed and used to investigate the seismic behavior of the connection.The results of the finite element model are validated by a set of cyclic loading tests.The cyclic loading tests and the finite element analyses indicate that the failure mode of the suggested connections is plastic hinge at the beam with inelastic rotation angle exceeding 0.04 rad.The suggested connections have sufficient strength,plastic deformation and energy dissipation capacity to be used in composite moment frames as beam-to-column rigid connections.

Influence of Axial Load Ratio on Shear Behavior of Through-Diaphragm Connections of Concrete-Filled Square Steel Tubular Columns

Nonlinear finite element analysis and parametric studies were carried out to study the influence of axial load ratio on the shear behavior of the through-diaphragm connections of concrete-filled square steel tubular columns. The analysis reveals that smaller axial load ratio can improve the shear bearing capacity and ductility while larger axial load ratio will decrease the shear behavior of the through-diaphragm connections. The parametric studies indicate that the axial load ratio should be limited to less than 0.4 and its influence should be considered in the analysis and design of such connections.

Low cyclic fatigue performance of concrete-filled steel tube columns

Eight concrete-filled steel tubular(CFT) columns were tested subjected to cyclic loading under constant axial load. Experimental parameters included axial compression ratio, loading sequences, and strength of concrete and steel. The seismic performance of CFT columns and failure modes were analyzed. The test results show that different axial load ratios and loading sequences have effects on the load carrying capacity, ductility and energy dissipation capacity of CFT columns, as well as the failure modes of the CFT columns. The failure pattern can be categorized into two types: local buckling failure of steel tube in compression zone, and low cycle fatigue tearing rupture failure of steel tube. The seismic behavior was evaluated through the energy index obtained from each cycle.

矩形钢管混凝土不等端弯矩偏压柱力学性能研究

通过改变端弯矩比、荷载偏心率等参数,对矩形钢管混凝土不等端弯矩偏压柱的力学性能进行了试验研究,并在此基础上对其受力全过程进行了有限元模拟计算。结果表明,由于构件细长比较小,其最终破坏形态为端部鼓曲破坏;刚度和极限荷载随构件荷载偏心率增大而减小,延展性增加;有限元计算结果与试验结果吻合。

方钢管混凝土轴压短柱承载力非线性有限元分析

采用大型通用有限元分析程序ABAQUS进行了方钢管混凝土轴压短柱力学性能模拟,分析了各个阶段构件的承载能力。结果表明:有限元计算的极限荷载和荷载-平均纵向应变曲线与试验结果符合较好,说明网格划分、边界条件、材料本构关系的选取基本正确,适用于钢管混凝土短柱的非线性分析。

高层钢-混凝土混合结构住宅的研究和设计

结合建设部2004年科技示范工程南宁湖滨大厦的设计,介绍钢-混凝土混合结构技术在高层住宅中的应用。讨论了高层住宅钢-混凝土混合结构体系的受力特点和弹塑性性能分析、基本构件和节点的计算与设计、矩形钢管混凝土柱的耐火设计,并对减少该体系钢柱与混凝土墙体这两类竖向构件差异提出相应措施。