钢管混凝土斜交网格平面相贯节点轴压承载力计算公式及有限元分析研究

相贯节点是钢管混凝土斜交网格结构设计的一个关键问题。针对两种新型节点构造形式，通过分析带不同厚度钢板的钢管混凝土短柱轴压承载力，提出了相贯节点轴压承载力计算公式，计算值与试验结果较为接近。本文采用有限元分析方法对节点静载试验进行了模拟，并分析了斜交角度、椭圆拉板厚度、衬板厚度、环向加强板和法兰板厚度等参数变化对节点承载力的影响。结果表明，有限元分析与试验结果吻合较好。节点中椭圆拉板的设置经济合理，衬板和环向加强板可提高对核心混凝土的约束效应。随着斜交角度、椭圆拉板厚度、衬板厚度的增加，节点承载力有所提高，而环向加强板或法兰板的厚度对节点承载力影响不大。总体而言，计算公式能较准确地估计节点的承载力，可用于工程实践。

Calculating Method of Bearing Capacity and Finite Element Study on Planar Intersecting Connections in CFST Diagrid Structures

Intersecting connection detail is a key challenge of structural design for concrete filled steel tubular (CFST) diagrid structures. An effective numerical model is proposed using finite element method to simulate the test of planar intersecting connections subjected to axial loading. According to the analyses for CFST stub columns with steel plate of different thicknesses, method for calculating the bearing capacity of two innovative intersecting connections is proposed and the calculated results are compared with test results. Furthermore, parametric studies using this nonlinear model are performed to investigate the variations in the intersecting angle, elliptical plate thickness, lining plate thickness, reinforcing plate and flange plate thicknesses. The results of finite element analysis (FEA) show good agreement with the test results. The elliptical plate, lining plate and reinforcing plate can enhance the confinement effect to the concrete core. In addition, with the increase of the intersecting angle, elliptical plate and lining plate thickness of the connection, the bearing capacity of the connection is increased. However, the reinforcing plate or flange plate thickness is not a significant parameter. In general, the proposed calculating method estimates the bearing capacity of the connection accurately, which can be applied in practical use.