【作者】 李毅；

【导师】 何益斌；

【作者基本信息】 湖南大学 ， 结构工程， 2012， 博士

【摘要】 中空夹层钢管混凝土是在内外两层同心钢管之间浇筑混凝土形成的组合构件，其内外层钢管取代了钢筋并对夹层混凝土产生约束作用，与传统的钢管混凝土构件相比，中空夹层钢管混凝土构件整体具有自重轻、抗弯刚度大、抗震性能好和耐火性能好的特性。目前对中空夹层钢管混凝土组合柱和钢管混凝土节点的研究国内外进行得较多，但对中空夹层钢管混凝土节点的研究还比较少，对节点的理论分析模型和计算方法都有待进一步研究。鉴于此，本文借鉴钢结构中常用的T型钢螺栓连接，将其引入组合节点中，采用贯穿柱身的双头等长高强度螺栓将中空夹层钢管混凝土柱与钢－混凝土组合梁连接在一起，从而形成一种新型的组合节点形式。在总结传统钢－混凝土组合节点的基础上，本文对该新型组合节点的性能进行了较为系统的试验研究、有限元模拟和理论分析并提出其相关的设计方法。主要的研究工作如下：（1）在广泛查阅国内外文献的基础上，对中空夹层钢管混凝土柱、钢－混凝土组合梁、T型钢连接和钢－混凝土组合梁节点的研究现状进行了较为全面的回顾和总结。并针对半刚性连接的特性进行了较为系统的分类以及对节点的弯矩－转角曲线的分析模型进行了探讨。（2）进行了6个十字形中空夹层钢管混凝土柱与钢－混凝土梁组合节点的拟静力试验研究。以柱轴压比、T型钢连接件尺寸、加劲肋、楼板厚度和楼板配筋率等为变化参数，采用梁端反对称加载形式，研究该组合节点的破坏特征、滞回性能、抗剪性能、承载力退化、刚度退化规律、耗能特性以及应变变化等力学性能。试验结果表明：尽管节点试件最终发生剪切破坏，但试件仍然具高的承载力、较大的初始转动刚度、良好的延性和耗能能力，说明其具有良好的抗震性能。（3）以节点试验为模型，分析时考虑节点组件的几何非线性、材料非线性和接触非线性问题，利用有限元软件ABAQUS对节点进行实体建模和网格划分，合理地模拟试验的边界条件和加载方式以及选择求解器，对节点受力进行全过程有限元分析。研究了组合节点中柱的轴压比变化、高强螺栓预拉力和钢筋混凝土楼板的组合效应等因素对节点受力性能的影响，将有限元分析结果与试验相比，二者吻合较好。同时获得了许多试验中无法得到的节点细部受力特性，如节点域柱夹层混凝土受力状况、T型钢翼缘接触应力分布规律、钢筋混凝土混凝土楼板的应力分布规律以及楼板主应力迹线分布特征等。（4）基于对十字形节点的传力机理分析，得出其可能出现的失效模式。在此基础上，采用弹性方法推导了节点开裂弯矩的计算公式；对比节点各个组件所确定的最大抗弯承载力和组合梁自身的最大抗弯承载力，推导了节点抗弯承载力计算公式；在分别建立节点域内外钢管腹板的三折线抗剪计算模型、节点域内外钢管翼缘的抗弯计算模型和节点域夹层混凝土的斜压杆计算模型的基础上，运用叠加原理建立了节点抗剪承载力计算公式；采用组件法建立了节点的初始转动刚度计算模型，由此建立了节点的弯矩－转角三段线骨架曲线模型；采用试验拟合法建立了考虑或不考虑滑移效应的荷载－位移滞回曲线三折线恢复力模型。（5）在总结全文试验研究、有限元模拟及理论分析的基础上，结合国内外的相关研究成果，提出了节点的抗弯承载力和抗剪承载力设计方法，以及提出了节点中相关组件的计算及构造措施建议，具体包括：中空夹层钢管混凝土柱、钢筋混凝土楼板、栓钉连接件、穿心螺栓、T型钢连接件、角焊缝和加劲肋等。上述研究成果表明：本文提出的T型钢螺栓连接组合节点具有良好的受力性能，能够满足地震区的组合框架结构或框筒结构的设计要求。本文的试验和理论研究成果可作为该类型组合节点在实际工程应用中的基础试验数据和理论依据。所建议的设计方法能为我国相关规范的编制提供有益补充和参考。更多还原

【Abstract】 Concrete-filled double skin steel tubular (CFDST) columns consist of twoconcentric steel tubes with concrete sandwiched between them. Its inner and outersteel tubes replace reinforcements and restrict the sandwiched concrete. Comparedwith the traditional concrete-filled steel composite component, the especialadvantages of CFDST include: lighter self-weight, stronger bending stiffness,favorable seismic behavior and reasonable fire resistance. The behaviors of CFDSTcolumn and concrete-filled steel tubular joint have been systematically investigatedby the researchers at home and abroad, but the research on CFDST joints has juststarted. The rational theoretical analysis model and the calculation method of jointsneed to be further studied. In view of the above mentioned situations, the T-stubsemi-rigid connection with stronger rigidity is introduced in composite joint in thisdissertation. The new form of joints, which are composed of CFDST column andH-shape steel beams with reinforced concrete slab using through high strength boltswith equal-length in both ends and T-stub connectors, have been reserached. Based onthe traditional research methods of steel-concrete composite joints, in the dissertation,the behaviors of new joint have been extensively investigated by experimental study,finite element simulation and theoretical analysis. The design methods of this newtype joint have also been discussed. The main achievements in the dissertation are asfollows:(1) Based on the wide range of the domestic and foreign literatures, thecomprehensive review and summary have been carried, including the present researchsituations of CFDST column, steel-concrete composite beam, T-stub connection andsteel-concrete composite joint. A systematic classification and study method ofsemi-rigid connections are analyzed. The models of moment-rotation relationship ofjoints have been discussed.(2) The pseudo static experiments on the behaviors of six crisscross joints of amoment-resisting frame consisting of CFDST column and steel-concrete compositebeam have been carried out. The test parameters varied included the axial load levelon the column, the size of T-stub, the stiffener, the thickness of slab and thereinforcement ratio in slab. To investigate the mechanical behaviors of the compositejoints, the failure modes, hysteretic behavior, shear strength, bearing capacitydegradation, stiffness degradation, energy dissipation and strain were evaluated in detail. To simulate the earthquake action, the antisymmetric loading forms at the endsof beams were adopted. The experimental results indicated that the shear failuremodes were arisen, but the new type joint were provided with higher carrying capacity,bigger initial rotational stiffness, good ductility and energy dissipation ability, whichindicated that the new type composite joints possess excellent seismic behavior.(3) Taking the test joints as prototypes, on the base of the geometricalnonlinearity, material nonlinearity and contacting nonlinearity of component of joints,the entity modeling and fine meshing of joint have been developed using the finiteelement software ABAQUS, which can reasonably simulate the experimentalboundary conditions, loading modes and select solver, so the entire loading process offinite element analysis has been conducted. The results of ABAQUS are good agreedwith the tests. The axial pressure ratio of CFDST columns, the preload of highstrength bolts and the composite effect of reinforced concrete slabs,which how toinfluence the mechanical behavior of composite joints, have been evaluated. Throughthe finite method analysis, lots of details can be got, which were indiscoverable intests, such as: the stress condition at panel zone sandwich concrete, the contact stressdistribution at T-stub flanges, the stress distribution and the main stress tracedistribution characteristics in reinforced concrete slab.(4) Founded on the analysis on force transmission mechanism of crisscross joint,the possible failure modes can be made. On this basis, the calculation formula of jointcracking moment has been deduced using the elastic method. The calculationformulas of joint moment capacities were established by contrasting the maximummoment capacity determined by components of joint and the composite beam itself.Base on the three broken lines calculation model of shear resistance in panel zonewebs of inner and outer steel tubes, the calculation model of moment resistance inpanel zone flanges of inner and outer steel tubes and the calculation model of diagonalcompression bar in panel zone concrete, the shear capacities of the joints have beenestablished using the superposition principle. A method has been developed forpredicting the initial rotational stiffness of the joints in both negative and positivemoment by the component method. On this basis, the trilinear skeleton curves ofmoment-rotation of the joints have been gotten. The three broken lines calculationmodels of load-displacement hysteretic loops of the joints have been establishedconsidering the slippage effect or not.(5) The moment capacities and shear capacities of semi-rigid T-stub joints havebeen proposed on the base of achievements of aforementioned the pseudo static tests, the finite element simulations, the theoretical analyses and existing relative researchachievements. The design or calculation method and construction requirements ofCFDST columns, reinforced concrete slabs, headed stud shear connectors, throughhigh strength bolts, T-stub connectors, fillet welds and stiffeners, et al.The research results show that: the proposed bolted T-stub compositeconnections exhibit good mechanical behaviors, meeting the design requirements ofcurrent codes for seismic resistant frames or frame-core wall structures. The test andtheory results of this dissertation can be used as the basic experimental data andtheoretical bases when the new type joints are applied in practical engineering. Thesuggested design methods can provide some beneficial supplements and reference torevision of future codes．更多还原