【作者】 王维；

【导师】 郑山锁；

【作者基本信息】 西安建筑科技大学 ， 结构工程， 2013， 博士

【摘要】 型钢混凝土（SRC）组合结构以其刚度大、承载能力高、抗震性能优越等优点，成为高烈度设防地区高层、大跨、重载及高耸结构的首选结构形式。鉴于试验采集到的试验数据普遍存在较大离散性且在数量上不具备统计意义，现阶段采用理论分析和数值方法相结合对相关科学问题进行探究不失为一种可行的研究手段。考虑到基于微观单元的数值模拟建模过程较为复杂，加之计算成本较高且对计算机硬件有着高标准需求，难以对大型复杂结构非线性力学行为进行有限元数值分析。借助宏观单元的有限元数值模拟在确保计算精度的前提下可实现对计算成本的有效控制，得到了广大科研工作者的青睐。为满足SRC框架结构宏观力学行为研究的需要，论文基于纤维单元模型理论并结合课题组前期关于型钢-混凝土间粘结滑移性能试验研究成果，在纤维层面上通过修正钢纤维的应变以实现对材料间粘结滑移的数值体现，使其更为精确地反映构件强非线性力学行为，同时提出了模拟SRC节点剪切变形的剪切块模型，并结合现阶段最新2D单元理论，从而构建了SRC节点单元，最终基于OpenSEES软件平台建立了SRC框架宏观有限元计算模型，取得了理想的验证效果。主要研究内容及研究结论有：1.分别采用宏观单元和微观单元对SRC柱抗震性能进行数值模拟分析，并结合试验实测数据，探讨了宏观单元和微观单元有限元数值模拟在单元原理、材料本构、网格划分、加载控制及模拟结果等方面的优缺点，提出了基于宏观单元的SRC梁-柱构件精细化建模方法，为深入进行SRC梁-柱宏观有限元理论研究奠定了基础。2.本课题组前期的研究成果表明，SRC构件在粘结滑移发生后，构件的承载力有较大改变。本文基于纤维单元模型理论，根据课题组前期提出的型钢-混凝土粘结滑移本构模型及粘结滑移沿截面高度的变化规律，提出在纤维层面上通过修正钢纤维应变的方法以实现对材料间粘结滑移的数值体现，该方法的意义在于精确的反映SRC构件非线性力学行为。3.为洞悉SRC节点内部应力的传递模式与分布情况，通过辅以微观有限元模拟以弥补试验研究无法观察节点内部应力分布形态的不足，对SRC平面框架涉及的中节点、边节点、角节点及屋面中节点进行剪切变形分析，结果表明节点内部应力主要分布在节点核心区型钢腹板、型钢翼缘内部混凝土斜压短柱及核心区外箍筋约束的混凝土斜压短柱区域，为建立剪力传递公式提供了分析依据。4.提出用于模拟SRC节点剪切变形的剪切块模型，并结合现阶段最新2D节点单元理论以构建SRC节点单元。根据SRC节点构造特点及内部应力传递模式与分布情况，认为SRC框架梁-柱节点剪力应由节点核心区型钢腹板、内部斜压杆及外部斜压杆三个部分承担，结合主要建筑材料的非线性本构模型，提出了SRC节点剪力传递公式，同时辅以试验得到的斜压杆宽度调整系数，最终建立了用于模拟SRC节点剪切变形的剪切块模型，随即利用C++计算机语言将剪切块模型编译为计算程序，以供2D节点单元程序调用，实现了SRC节点单元的数值体现。5.将纤维单元精细化模拟SRC梁-柱构件的方法与SRC梁-柱节点单元相结合，基于OpenSEES软件平台建立SRC框架宏观有限元计算模型。试验结果与模拟结果对比表明，本方法建立的SRC框架模型较好的模拟了SRC框架循环荷载作用下的力学响应。更多还原

【Abstract】 Due to the high rigidity, high bearing capacity, superior seismic performance and otheradvantages, SRC composite structures become the preferred structures used in the high-rise,long-span, heavy-load and towering structures in high intensity security areas. Because theexperimental data collected from tests generally has larger discreteness and is not enough tohave statistical significance, the research method combining theoretical analysis and numericalsimulations to explore the relevant scientific problems is feasible recently. Considering thecomplexity of the numerical simulation modeling process based on the microscopic element,the high computation cost and the strict requirements to computer hardware, the finite elementnumerical analysis on the nonlinear mechanical behavior of large complex structures is hard toconduct. Under the help of macroscopic element, the effective control of computation cost canbe realized with the finite element numerical analysis in the premise of ensuring calculationaccuracy, which is popular in the large number of research workers.To meet the needs of the research on the macroscopic mechanical behavior of SRC framestructure, the numerical simulation of the bond-slip between materials is realized by modifyingthe strain of steel fiber in the fiber level, based on the fiber element model theory and combinedwith the research results from the previous performance test of the bond-slip between steel andconcrete in our team. The strongly nonlinear mechanical behavior of components is reflectedmore accurately. At the mean time, the shear block model used to simulate the sheardeformation of the SRC joints is proposed. And combined with the latest2D element theory atpresent, the SRC joints element is built. Based on the platform of OpenSEES software, themacroscopic finite element calculation model applied to SRC frame structure is established andis verified well. The main research work and research conclusion are as follows:1. The numerical simulations analysis on the seismic performance of SRC columns using macroscopic element and microscopic element is conducted respectively. And combined withthe measured data of tests, the advantages and disadvantages between the macroscopic finiteelement numerical simulation and the microscopic finite element numerical simulation in theelement principle, the material constitutive, the meshing means, the load control, the simulationresults and other aspects are explored. The refined modeling method applied to beam-columncomponents based on the macroscopic element is put forward, which lays the foundation toimplement the research on the macroscopic finite element theory applied to the SRCbeam-column components in deep.2. The previous research results in our team show that the bearing capacity of componentsis changed a lot after the bond slip of SRC components have occurred. Based on the fiberelement model theory, the numerical simulation of the bond slip between materials is realizedby modifying the strain of steel fiber in the fiber level, according to the bond-slip constitutivemodel of steel concrete and the variation rule of bond slip along the section height proposedpreviously in our team. The significance of this method lies in that the nonlinear mechanicalbehavior of SRC components is reflected accurately.3. In order to detect the delivery mode and the distribution of the inner stress in SRC joints,the insufficiency that the distribution patterns of the inner stress in joints cannot be observedthrough the test is made up with the simulation of microscopic finite element. The sheardeformation of the middle joints, side joints, corner joints and middle joints on the roofinvolved in SRC plane frame is analyzed. It is showed that the inner stress in joints is mainlydistributed in the steel webs of the joint core area, the oblique compression concrete columns inthe steel flange and the inclined concrete columns area restrained with stirrups out of the corezone, which provide the analysis basis to establish the shear transfer formula.4. The shear block model used to simulate the shear deformation of SRC joints is putforward. And combined with the latest2D element theory at present, the SRC joints element isbuilt. According to the construction features of SRC joints, the delivery mode and thedistribution of the inner stress, it is considered that the shear of SRC frame beam-column jointis beard with three parts as steel webs of the joint core area, the internal oblique compressionbar and the external oblique compression bar. Combined with the nonlinear constitutive modelof main construction materials, the shear transfer formula of SRC joints is proposed. Thecoefficient to adjust the width of the oblique compression bar is obtained with the test. The shear block model used to simulate the shear deformation of SRC joints is established finally.Then the shear block model to be called by2D joints element is compiled into the calculatingprograms with C++computer language. Then the numerical simulations of SRC joints elementis realized.5. Combining the method that simulate SRC beam-column by using fiber element with theSRC beam-column joint element, the macroscopic finite element calculation model of SRCframe is established based on the platform of OpenSEES software. Comparing the test resultswith the simulation results, it is showed that the mechanical response of SRC frame subjected tocycle loading is simulated well with the SRC frame model set up in the paper.更多还原