Connections to Concrete-Filled Steel Tubes

该项目对钢-混凝土组合结构体系进行研究，钢-混凝土组合结构体系在当今建筑框架结构中变得越来越普遍。组合结构的一种常见类型是带有组合主柱的钢框架。这结合了轻质延性钢框架的优点和钢-混凝土组合柱的附加刚度来控制侧移。本文的研究重点是钢管混凝土柱节点的性能。对框架结构进行了弹塑性抗震分析，对具体细节进行了弹塑性有限元分析，并对关键节点进行了试验。评估了目前这些组合构件的有限实践，并为连接细节的安全和经济设计提供了指南。研究了与穿透钢管的构件的连接以及与管壁外部的钢-钢连接。考虑了几个细节问题，包括：没有剪力连接件的构件的嵌入长度，梁柱节点区域所需的管壁厚度，钢管与混凝土核心之间的必需粘结与可用粘结，混凝土核心的徐变和收缩，以及连接处混凝土的压碎和管壁的屈曲。预计这项研究的结果将激发设计界的广泛兴趣。组合结构与传统的结构体系相比有许多优点，这项研究将是使钢管混凝土柱在未来的使用中变得更加可行和实用的第一步。

This project conducts studies in steel-concrete composite structural systems which are becoming more prevalent in building frame construction today. A common type of composite structure is a steel frame with composite primary columns. This combines the advantages of a light-weight, ductile steel frame with the added stiffness of steel-concrete composite columns to control lateral drift. The focus of this research is on the performance of connections to concrete-filled tube columns. An inelastic seismic analysis of building frames, an inelastic finite element analysis of the specific details and experimentation of critical connections are carried out. The current limited practices of these composite elements and provide guidelines for the safe and economical design of connection details are assessed. Connections with elements that penetrate the steel tube and steel-to-steel connections to the exterior of the tube wall are investigated. Several detailing issues are considered, including: embedment length of members without shear connectors, required thickness of the tube wall in the area of the beam-to-column joint, required vs. available bonding between the steel tube and concrete core, creep and shrinkage of the concrete core, and crushing of the concrete and buckling of the tube wall at the connection. It is expected that results from this research will stimulate wide-spread interest in the design community. Composite construction has many advantages over the more traditional structural systems, and this research will be the first step in making concrete-filled steel tube columns more feasible and practical for future use.