【作者】 周天华；

【导师】 何保康；

【作者基本信息】 西安建筑科技大学 ， 结构工程， 2004， 博士

【摘要】 本文在总结分析了国内外关于钢管混凝土框架节点研究与应用现状的基础上，以实际工程为背景，在国内首次进行了A、B两组共6个足尺节点试件的低周反复循环加载试验，其中A组三个试件梁端采用栓-焊连接；B组三个试件梁端为全对接焊接。试验结果表明：6个试件的层间位移延性系数μ≈2.28～3.86，弹性极限层间位移角φ_y≈0.011～0.014rad，弹塑性极限层间位移角φ_u≈0.0297～0.0424rad，节点梁柱的相对极限塑性转角θ_u≈0.0163～0.0343rad，能量耗散系数E≈1.946～2.216；A、B两类节点均有良好的抗震性能，在相同轴压比下A类节点的延性较B类略好一些，而耗能能力B类节点却略大一些，但二者相差不大，均满足结构抗震设计的要求。根据试验结果提出了节点构造建议。 在总结前人研究的基础上，建立了同时考虑大变形的几何非线性、高强螺栓连接的面—面接触非线性、各种材料非线性等三重非线性因素的有限元理论分析模型，利用大型非线性有限元软件ANSYS6.1，对钢材采用Von.Mises屈服条件和运动强化本构关系，对混凝土采用William-Warnke五参数破坏准则和弹塑性本构关系，对混凝土裂缝和高强螺栓连接的面-面接触等问题利用ANSYS6.1提供的判别准则，第一次采用三维实体单元对“带内隔板方钢管混凝土柱-钢梁节点”进行了三维建模，并模拟分析了单调和低周反复加载下节点的受力性能，较为精确地分析了节点区应力分布，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，并通过理论分析与试验结果进行比较分析，提出设计和方钢管棍凝土柱一钢梁框架节点的抗震性能及承载力研究改进建议。根据本文的试验和理论研究结果，对((矩形钢管混凝土结构技术规程》(送审稿)带内隔板的梁一柱栓焊连接节点设计内容进行了评析，提出了构造建议，并给出了梁柱连接处梁截面的抗弯、剪计算公式。对节点核心区的抗剪，通过受力机理的分析，建立了钢“框架剪力墙”加混凝土“斜压短受力体系及其屈服机制，根据塑性极限分析，给出了节点核心区抗剪承载力计算的迭加公式，《规程》公式和非线性有限元近似模拟分析结果进行了比较。本文提出的节点核心区抗剪承载”与柱并力计算公式，能够反映出轴压比的影响，理论相对比较完善，公式的力学概念较明确、简单，其计算结果安全、合理，可供实际工程设计参考。更多还原

【Abstract】 Based on the investigation of research and application of concrete-filled tubular column to steel beam connections in China and abroad, according to engineering practice, six full-size specimens that the joints composed by concrete-filled square tubular column and I-shape steel beam divided as A and B groups have been tested under cyclic-loading in this paper. The three specimens of group A are connected by bolt-weld and the group B connected by welded at the end of beams. Results of the experiment show that six specimens’ story deflection ductility ratio μ≈2.28~3.86,elastic ratio of story deflection rotation φy≈ 0.011-0.014rad, elastic-plastic ratio of story deflection rotation φu≈0.0297 ~0.0424rad,relative plastic rotation ratio of beam-column θu≈0.0163~0.0343rad and energy dissipation ratio E≈1.946~2.216. All the specimens of group A and B have excellent seismic behavior, the ductility of the specimens A is better than specimens B but the energy dissipation capacity of the specimens B is a bit better than specimens A under the same axial compression force ratio. However, both of the A and B specimens satisfy requirements of the structural seismic design. Some suggestions for improving joint construction are presented according to the results of experiment research.Based on the achievements in theoretical research, the nonlinear FEM model involving geometric large deformation, contact-friction of high-strength bolts and materials nonlinear is presented. The Von.Mises failure criterion and multiplier kinematical hardening stress-strain relationships have been used for steel and the William-Wamke failure criterion and elastic-plastic stress-strain relationships used for concrete . The concrete cracking and contact-friction of bolts connections are used for the discriminating criteria in terms of ANSYS6.1. The 3D models of beam-to-column connections with internal diaphragms by 3D solid elements are founded. And the capacity behavior of connections under the monotonic loading and cyclic loading are analyzed. The results of nonlinear FEM analyses can show the stresses distribution in the joints better, so that it provides the possibility to patch up the defects that couldn’t observe in experiments in the details. 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 analyses with that of experimental results.According to the results of theory and experimental researches in this paper, the design provisions in the ’Technical Code for Concrete-Filled Square Tubular Structure"(Draft) are discussed. The load-carrying capacity formulations for end section of beam to at the column-beam connections are proposed. Based on the analysis of mechanism for joint region, the "frame-wall" and "aslope compression stub column" mechanical models and yielding patterns of core zone of the joints are set up. The shear load-carrying formulation for joint core zone is also given in terms of plastic ultimate analysis. And then, the comparisons between the formulas given in this paper and that of Chinese Design Code (draft) and nonlinear FEM as well are presented. Comparison shows that the formulas for determination of shear capacity of core zone at joints presented in this paper are much better, simple and safety. And the formulas also can express the changes for axial compression ratio of columns, so they can provide the reference to the engineering design.更多还原