法兰连接钢管混凝土柱-钢梁外加强环节点受力性能研究

Study on mechanical behavior of flange-connected CFST column-steel beam joint with external stiffening ring plate

钢管混凝土柱-钢梁混合结构是工程常用的结构形式。为了有效减小钢管混凝土结构在施工现场的焊接工作量,提高钢管混凝土柱-钢梁节点的安装效率,提出了一种基于法兰连接和外加强环的钢管混凝土柱-钢梁连接装配方法,其特点是采用高强螺栓、刚性法兰盘、外加强环板在同一位置实现了钢管混凝土柱-柱连接、钢管混凝土柱-钢梁连接。对采用该方法装配的4个法兰连接钢管混凝土柱-钢梁组合体试件进行低周反复加载试验,验证了上述法兰连接钢管混凝土柱-钢梁外加强环节点的受力性能。采用有限元数值模拟方法对法兰连接钢管混凝土柱-钢梁的组合体试件进行了参数分析,经统计回归提出了适用于法兰连接钢管混凝土柱-钢梁节点的外加强环板的改进设计方法,并完善了钢管混凝土柱法兰连接的设计过程。研究结果表明:法兰连接钢管混凝土柱-钢梁外加强环节点抗震性能较好;加强环板宽度是影响其受力性能的重要因素,外加强环板的改进设计方法可以合理考虑法兰盘的贡献和柱钢管在节点处不连续的影响。

Concrete filled steel tubular(CFST)column-steel beam hybrid structure is commonly used in engineering structures.In order to effectively reduce the weld work in CFST structures in the construction site,and to improve the installation efficiency of CFST column-steel beam joints,a new assembling method for CFST column to steel beam connections employing flange connection and external stiffening ring plate was proposed.The characteristics of this assembling method are that the CFST column to CFST columns and the beam to CFST column joints are realized at the same position by adopting high-strength bolts,rigid flange plate and external stiffening ring plate.Low cycle loading tests on four flange-connected CFST column-steel beam subassemblage specimens have been carried out.The mechanical behavior and design method of the assembling method have been verified.Finite element numerical simulations were carried out to perform the parametric analysis of flange-connected CFST column-steel beam subassemblage specimens.The design method for external stiffening ring plate which was used for flange-connected CFST column-steel beam joints was proposed based on the statistical regression analysis,and the design process for flanged connection of CFST columns was developed.The results show that flange-connected CFST column-steel beam joint with external stiffening ring plate has good seismic behavior,the width of stiffening ring plate is an important factor affecting the mechanical behavior of the joint.The contribution of flange plate and the influence of discontinuous column steel pipe at joint can be reasonably consider by the modified design method of external stiffening ring plate.