柔性连接新型砌体填充墙框架结构抗震性能研究

发布时间：2018-10-07 20:52

【摘要】：考虑到填充墙和主体框架间存在复杂的相互作用,砌体填充墙框架结构可视具体情况采用两种设计计算方法:第一种方法视填充墙为结构构件,设计计算时计入填充墙对结构刚度和承载力的影响,此时填充墙应与周边框架可靠连接,形成组合墙;第二种方法视填充墙为非结构构件,设计计算时只计入填充墙重量,简化考虑或不考虑其对结构刚度及承载力的影响,此时填充墙应与框架梁柱之间预留足够的间隙,隔离两者的相互作用,即采用墙—框柔性连接施工方案。本文针对新型填充墙体材料“粉煤灰自保温空心砌块”,系统开展墙—框柔性连接砌体填充墙框架结构的抗震性能研究,具体研究工作及创新点如下:(1)进行了粉煤灰空心砌块砌体抗压及抗剪强度试验,根据试验结果,得到空心砌块砌体抗压及抗剪强度计算公式、泊松比、弹性模量和剪切模量等力学指标,提出了砌体受压应力-应变关系及剪应力-剪应变关系,以及剪压复合作用下空心砌块砌体抗剪强度计算公式。(2)进行了空心砌块墙体低周往复荷载试验,结果表明,当墙体设置芯柱后,其水平承载力、刚度、延性和耗能能力都有明显改善。(3)通过7榀1:2钢筋混凝土空心砌块填充墙框架结构低周往复荷载试验,系统研究了墙—框柔性连接和刚性连接、填充墙两端设置芯柱和不设置芯柱、全墙填充和半墙填充框架结构的破坏机理和抗震性能,进行了结构滞回特性、承载力、位移延性、刚度退化、强度衰减、耗能能力及变形性能指标分析。结果表明:柔性连接方案对结构承载力的提高低于刚性连接方案,但其他性能指标均优于刚性连接方案,说明柔性连接方案减小了墙—框相互作用,有效改善了填充墙框架结构的抗震性能。同时,柔性连接方案减小或消除了填充墙对框架柱的附加剪力影响,改善了框架柱的受力性能,减轻了填充墙破损程度。另外,填充墙端芯柱的设置有效提高了结构承载力、刚度和整体稳定性。(4)采用均质化建模方式进行了空心砌块墙体单调水平加载下的非线性有限元分析,验证了本文提出的粉煤灰空心砌块砌体泊松比取值、抗压强度、弹性模量计算公式,以及受压本构关系的可靠性。(5)分别采用两种建模思路进行了空心砌块砌体填充墙框架的数值模拟分析:一种方法是用均质化模型模拟填充墙,进行水平往复荷载作用下的静力弹塑性分析;另一种方法是用等效弹簧单元模拟填充墙,进行单调水平荷载作用下的静力弹塑性分析。两种方法的计算结果与试验结果吻合较好。
[Abstract]:Considering the complex interaction between the infilled wall and the main frame, the masonry infilled wall frame structure can be visualized by two design and calculation methods: the first method regards the infilled wall as a structural member. In the design and calculation, the influence of the infilled wall on the stiffness and bearing capacity of the structure is taken into account. In this case, the infilled wall should be reliably connected with the surrounding frame to form a composite wall. The second method regards the infilled wall as a non-structural member, and only takes into account the weight of the infilled wall in the design calculation. In order to simplify or not consider the influence on the stiffness and bearing capacity of the structure, the infill wall and the frame Liang Zhu should have enough clearance to isolate the interaction between them, that is to say, the construction scheme of flexible connection between the wall and frame should be adopted. In this paper, the aseismic behavior of the infilled wall frame structure with flexible connection of wall and frame is studied systematically, aiming at the new type of filled wall material "fly ash self-insulating hollow block". The specific research work and innovation points are as follows: (1) the compressive and shear strength tests of fly ash hollow block masonry are carried out. According to the test results, the formula for calculating compressive and shear strength of hollow block masonry, Poisson's ratio, is obtained. The compressive stress-strain relationship and shear stress-shear strain relationship of masonry are presented. The calculation formula of shear strength of hollow block masonry under the action of shear-compression composite is given. (2) the low cycle reciprocating load test of hollow block wall is carried out. The results show that the horizontal bearing capacity and stiffness of hollow block masonry are calculated when the core column is installed. The ductility and energy dissipation capacity are improved obviously. (3) through the low cycle reciprocating load tests of 7 1:2 reinforced concrete hollow block filled wall frame structures, the flexible and rigid connections of wall and frame are systematically studied. The failure mechanism and aseismic performance of the frame structure filled with whole wall and half wall are analyzed. The hysteretic characteristics, bearing capacity, displacement ductility, stiffness degradation and strength attenuation are carried out. Analysis of energy dissipation capacity and deformation performance index. The results show that the bearing capacity of the flexible connection scheme is lower than that of the rigid connection scheme, but the other performance indexes are better than the rigid connection scheme, which indicates that the flexible connection scheme reduces the wall-frame interaction. The seismic behavior of infilled wall frame structure is improved effectively. At the same time, the flexible connection scheme reduces or eliminates the additional shear effect of the infilled wall on the frame column, improves the mechanical behavior of the frame column, and reduces the damage degree of the infilled wall. In addition, the installation of end core column of filled wall can effectively improve the bearing capacity, stiffness and overall stability of the structure. (4) the nonlinear finite element analysis of hollow block wall under monotonic horizontal loading is carried out by using homogeneous modeling method. The formula for calculating Poisson's ratio, compressive strength and elastic modulus of fly ash hollow block masonry is verified. And the reliability of compressive constitutive relation. (5) the numerical simulation analysis of hollow block masonry infilled wall frame is carried out using two kinds of modeling ideas: one method is to simulate the filled wall with homogenization model. The static elastic-plastic analysis under horizontal reciprocating load is carried out, and the equivalent spring element is used to simulate the infilled wall, and the static elastic-plastic analysis under monotone horizontal load is carried out. The calculated results of the two methods are in good agreement with the experimental results.
【学位授予单位】：天津大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TU364;TU352.11

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