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.

内置开孔钢板加劲肋的L形宽肢钢管混凝土组合柱轴压性能研究

为研究内置开孔钢板(PBL)加劲肋的宽肢钢管混凝土组合柱(W-LCFST)的轴压性能,以L形双板连接钢管混凝土组合柱(LCFST-D)的轴压试验为基础,开展了W-LCFST柱参数化分析。结果表明:添加PBL加劲肋可增强混凝土和钢板之间的相互作用,与未添加PBL加劲肋的试件相比,添加1组PBL加劲肋,承载力提高了3.8%~5%,延性系数提高了14.3%~25.7%;添加2组PBL加劲肋,承载力提高了7.9%,延性系数提高了29.2%。最后,基于Mander理论,提出了预测W-LCFST柱截面承载力的计算公式,并将预测公式计算结果、日本规范Recommendations for design and construction of concrete filled steel tubular structures(AIJ-CFT(1997))、美国规范Load and resistance factor design specification for structural steel buildings(AISC-LRFD(1999))、《矩形钢管混凝土结构技术规程》(CECS159:2004)分别与有限元结果进行了对比。结果表明:上述公式计算结果均较为保守,但所提出的预测公式计算结果更加准确,平均误差为7%。

钢管混凝土柱在大跨度高层电信建筑中的应用研究

通过对钢管混凝土柱、节点的理论分析及节点试验论证,证明钢管混凝土柱对大跨度高层电信建筑是一种行之有效的结构方案。

隐式框架钢结构住宅体系的研发与实践

本文介绍了我国装配式钢结构住宅的发展历程、钢结构住宅的常用建筑形式与构件,以及目前业内对钢结构住宅的关注点。针对目前普遍存在的问题,介绍了隐式框架的改善创新和科研成果,主要从体系构成、构件形式、连接节点和配套材料选用等几个方面展开,并讲述了其特点和优点。最后部分介绍了隐式框架钢结构住宅体系在云南、四川、山东、河南、山西、浙江等地工程应用的案例情况。隐式框架钢结构住宅体系,是目前国内众多钢结构住宅体系中的一种解决方案,具有工业化程度高、产品标准化与工业化、符合规范便于审图、制作简单便利、节约造价等特点,可以为业内装配式钢结构住宅的工程项目提供一种应用参考。