中文摘要：

采用ABAQUS分析软件对圆钢管混凝土X型节点进行轴压荷载作用下的非线性分析，依据轴压荷载作用下节点各组成部分的应力分布情况及圆钢管混凝土节点承载力随相贯角度、宽厚比、竖向连接板厚度、衬板厚度、混凝土强度等控制参数的变化曲线，提出了节点承载力的计算式模式，通过拟舍得出最终的节点承载力计算式。研究表明：相贯角度、宽厚比、混凝土强度对其承载力影响较大，竖向连接板的厚度、衬板厚度对其承载力影响相对较小；所提出的节点承载力计算式精确度较高且偏为安全，可用于工程实际中构件承载力的计算。

英文摘要：

The finite analysis software ABAQUS was used to conduct the nonlinear analysis of X-joint of circle concretefilled steel tube （CFST） under axial compression load. The calculation formula of bearing capacity on the joints was proposed based on the stress distribution of each component of joints under axial compression load and the circle CFST joint＇ s bearing capacity curves that changing with control parameters of intersecting angle, width-thickness ratio, thickness of vertical connecting plate and lining plate, concrete strength and stiffening ring thickness. Then the ultima calculation of bearing capacity of joints was obtained by fitting. The results showed that intersecting angle, width-thickness ratio and concrete strength all had great influence on the bearing capacity of the X-joint, while thickness of vertical connecting plate had little influence on the bearing capacity of the X-joint. The formula of bearing capacity could be used in actual projects to calculate the bearing capacity of members due to its high accuracy and safety.