Connections to Concrete-Filled Steel Tubes

本项目对钢-混凝土组合结构体系进行了研究，目前钢-混凝土组合结构体系在建筑框架结构中越来越普遍。一种常见的组合结构是钢框架与组合主柱。这结合了轻质、延展性钢框架的优点和钢-混凝土组合柱的刚度来控制横向漂移。本文研究的重点是钢管混凝土柱的连接性能。对建筑框架进行了非弹性地震分析，对具体细节进行了非弹性有限元分析，并对关键节点进行了试验。评估了目前这些复合元件的有限实践，并为连接细节的安全和经济设计提供了指导。研究了穿透钢管的元件连接以及与管壁外部的钢对钢连接。考虑了几个细节问题，包括：无剪切连接件的构件的预埋长度，在梁柱结合处的要求管壁厚度，要求与钢管和混凝土核心之间的可用粘结，混凝土核心的蠕变和收缩，混凝土的破碎和管壁在连接处的屈曲。预计这项研究的结果将激发设计界广泛的兴趣。与传统的结构体系相比，组合结构具有许多优点，本研究将是使钢管混凝土柱在未来的应用中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.