钢管混凝土斜柱转换节点的力学性能与设计方法研究

The reseachers and engineers have pay attention to the inclined column-shaped transfer structure, in which the inclined columns and supporting column are both concrete-filled steel tubular members. Because this kind of structure has the advantages of both concrete-filled steel tubular structure and inclined column-shaped transfer structure. The joint intersected by several concrete-filled steel tubular inclined columns, beams and the supporting column, is the most important part and the key designing issue of this kind of transfer structure. However, the related reseach results and the construction forms of this kind of joint are rare. And it is far from enough in studying the mechanical behavior of the core area of joint subjected to both the forces from the inclined columns and beams. In this study, by setting strengthen rings and ribbed slabs, a new constructional measure of this kind of joint connected with steel beams is proposed. Tests will be conducted to study the mechanical behavior of this kind of joint subjected to two different load cases. Based on the experimental results, in combination with the numerical study and the theoretical study, several aspects on the mechanical behavior of this kind of joint will be studied, as follows. The effects of different parameters on the failure modes, the transfer mechanism, and the mechanical behavior will be studied. The load transfer mechanical model in different failure modes, subjected to both the forces from the inclined columns and beams, will be developed. A set of design methods of this kind of joint will be established, including the reasonable value ranges of the construction parameters and the methods for evaluating the bearing capacity. The results of this study can provide significant academic value for perfecting the theoretical research system, about the mechanical behavior of the joint of concrete-filled steel tubular structure under complex load conditions. Meanwhile, it has significant meaning on the application development of the steel-concrete composite structure and the inclined column-shaped transfer structure in the high-rise buildings.

结合钢管混凝土与斜柱转换结构的优点，斜柱和竖向支柱均为钢管混凝土的斜柱转换结构已受科研和工程设计人员重视。钢管混凝土斜柱转换节点是钢管混凝土斜柱、支柱、周边梁相连接的节点，是该类型结构中最重要的部位。相关研究成果很少，且节点形式单一，对斜柱内力和梁端内力共同作用下节点域受力性能的研究也很不完善。本课题中首先提出一种新型带加强环和肋板、连接钢梁的钢管混凝土斜柱转换节点构造形式，然后通过节点模型在不同加载工况下的力学性能试验，结合数值模拟分析和理论研究，研究不同因素对新型节点破坏机制、传力机理、力学性能的影响，研究斜柱内力和梁端内力共同作用下不同破坏机制的节点传力力学模型，研究节点设计参数的合理设置值、承载力计算公式，建立设计方法。预期成果对完善复杂荷载作用下钢管混凝土节点受力性能理论体系有重要学术价值，对开拓钢-混凝土组合结构、斜柱转换结构在高层建筑领域的应用有重要意义。

结合钢管混凝土与斜柱转换结构的优点，斜柱和竖向支柱均为钢管混凝土的斜柱转换结构已受科研和工程设计人员重视。钢管混凝土斜柱、支柱、周边梁相连接的节点是该类型结构中最重要的部位。相关研究成果很少，且节点形式单一，对斜柱内力和梁端内力共同作用下节点域受力性能的研究也很不完善。本课题开发了两种新型带加强环和肋板、连接钢梁的钢管混凝土斜柱转换节点构造形式，完成了共18个试件在不同加载工况下的力学性能试验，包括8个试件在斜柱端部对称竖向荷载作用下的试验研究，6个试件在梁端低周往复荷载作用下的试验研究，4个试件在梁端固定反向荷载、斜柱端单调加载作用下的试验研究。结合数值模拟分析，研究了不同参数下新型节点的破坏机制和传力机理，研究了节点传力力学模型，研究了经优化后的节点设计参数的合理设置值、承载力计算公式，建立了设计方法。研究结果表明斜柱插入深度是影响斜交区力学性能最关键的参数；通过合理设计，节点核心区的承载力和刚度能满足“强节点”的设计要求。研究成果对完善复杂荷载作用下钢管混凝土节点受力性能理论体系有重要学术价值，对开拓钢-混凝土组合结构、斜柱转换结构在高层建筑设计领域的应用有重要意义。