中文摘要：

为研究主管轴力、内填混凝土对方钢管节点受拉力学性能的影响,文章进行了X型节点受拉的非线性有限元分析。以方钢管混凝土X型节点受拉试验为研究原型,改变主管的轴力比、宽厚比、支主管宽度比等参数,设计了12个方钢管混凝土和12个方钢管X型受拉节点试件,分别从节点承载力、抗拉刚度、支主管应力分布等方面进行了对比分析。结果表明：改变主管轴拉比、支主管宽度比及主管宽厚比,方钢管混凝土相对于方钢管的节点承载力提高均不显著;主管受轴压力作用时,方钢管混凝土节点承载力高于方钢管节点;方钢管混凝土节点的抗拉刚度、抗疲劳性能显著高于方钢管节点。

英文摘要：

The nonlinear finite element analysis of X-connections was done to study the mechanics of square steel tube connections influenced by axial load and concrete.Based on the experiment of concrete-filled square steel tube X-connections subjected to tension,the axial load ratio,thickness ratio of chord and width ratio between branch and chord were changed.Twelve concrete-filled square steel tube X-connections and 12 square steel tube X-connections were designed for the numerical model.The differences among joints ability,tensile stiffness and stress distribution in branch and chord were analyzed.The results show that the joints ability of concrete-filled square steel tube X-connections is higher than that of square steel tube X-connections under the compression on chord.There is no significant enhancement in joints ability of square steel tube X-connections filled with concrete in different axial tensile ratio,thickness ratio of chord and width ratio between branch and chord.Compared with square steel tube,concrete-filled square steel tube X-connections have higher tensile stiffness and better anti-fatigue performance.