方钢管混凝土柱-钢梁节点的非线性有限元分析

Nonlinear FEM analysis of bearing capacity behavior of concrete-filled square tubular column and steel beam joints

利用三维实体单元,对“带内隔板方钢管混凝土柱-钢梁节点”建立了同时考虑几何非线性、高强螺栓连接的面—面接触非线性、各种材料非线性等因素的有限元理论分析模型,模拟分析了单调加载和低周反复加载时节点的受力性能,较为精确地分析了节点区应力分布和混凝土开裂情况,以弥补试验中无法直观地了解各细部受力情况和改变各种参数进行对比的缺陷;考察了轴压比大小、混凝土强度等因素对节点受力性能的影响,根据理论与试验结果分析,提出了设计和改进建议。

The nonlinear FEM models of concrete-filled square tubular column and steel beam joints involving geometric large deformation, contact-friction of high-strength bolts and materials nonlinear is presented. The 3D models of beam-to-column connections with internal diaphragms by 3D solid elements are founded. And the bearing capacity behavior of connections under the monotonic loading and cyclic loading are analyzed. The results of nonlinear FEM analysis show the stresses distribution in the joints better, so that it provides the possibility to patch up the defects that couldn＇t observe in detail in experiments. And then, various factors of the influences of joints capacity behavior can be analyzed such as changing axial compression force ratio and concrete strength etc. Finally, some suggestions for improving joint design are presented according to comparison of theoretic analysis with that of experimental results.