中文摘要：

钢管混凝土叠合柱-钢梁框架体系已经在实际工程中得到了应用,但对于其节点工作机理尚不明确,在合理选择材料模型、单元类型和接触模型的基础上,建立可用于钢管混凝土叠合柱-钢梁节点全过程受力分析的有限元模型。模型中同时考虑几何非线性和材料非线性的影响,采用有限元模型模拟4榀在柱端恒定轴压力和梁端侧向力共同作用下的组合节点试件,计算结果与试验结果吻合良好。在此基础上,利用有限元模型对节点受荷全过程中各部件的应力和应变发展进行细致分析,明晰节点的工作机理。

英文摘要：

Concrete encased concrete filled steel tube（ CFST） column to steel beam frame system has been used in real structures,but the working mechanism of the composite joint is still unclear. Thus by appropriate selection of material model,element type and contact model,it was developed a nonlinear finite element analysis（ FEA） model of concrete encased CFST column to steel beam joints under constant axial load in the column and incremental lateral load at the beam ends. The modelling of material properties of concrete and steel and interaction between them were taken into consideration in the FEA model,where both material and geometric nonlinearities were included as well.The calculated results agreed well with the test results,in terms of failure mode and load versus displacement response. Then using the FEA model,the stress and strain of the components of joint were detailedly analyzed during the whole loading process,and the working mechanism of the joint was clarified.