框架砌体填充墙干缩机理及裂缝控制研究

发布时间：2018-03-07 19:09

本文选题：框架砌体填充墙　切入点：干缩机理　出处：《浙江大学》2014年博士论文　论文类型：学位论文

【摘要】：在框架砌体填充墙结构中,墙体的干缩开裂是其常见的失效模式,墙体干缩裂缝的出现降低了建筑的适用性、耐久性及保温节能效果。因而分析框架砌体填充墙干缩变形产生的机理,研究有效的裂缝控制措施变得尤其重要。本文以现场调研、理论推导、试验研究、有限元模拟为技术手段主要进行了框架砌体填充墙结构开裂现场调研、墙体材料干缩机理研究、墙体材料干缩试验、框架砌体填充墙开裂的分离式有限元模拟、框架砌体填充墙裂缝控制措施分析、开洞框架填充墙体裂缝控制等方面的研究工作,取得了以下主要研究成果： 1.考虑界面内外压力差的影响推导了改进的杨氏关系式,研究成果能更好的解释浸润角随液面内外压力差变化这一自然界物理现象。 2.推导了均匀孔径和缩减孔径平滑毛细管结构在水分蒸发过程中管壁径向应力变化计算公式,得出平滑毛细管结构在水分蒸发过程中管壁膨胀的结论。提出了不平滑毛细管张力理论模型,推导了毛细水损失过程中不平滑毛细管结构径向变形及轴向变形计算公式。 3.建立了框架砌体填充墙结构的分离式有限元模型,定量分析了墙体长度、框架刚度、灰缝抗拉强度、边界条件、构造措施、干缩率等因素对填充墙体不同部位裂缝出现及裂缝宽度的影响。 4.基于分离式有限元模型及砌块干缩试验结果,定量分析了各种裂缝控制措施的裂缝控制效果,给出了基于框架填充墙体裂缝控制的墙体长度限值。
[Abstract]:In the frame masonry infilled wall structure, the dry shrinkage cracking of the wall is the common failure mode, and the appearance of the wall dry shrinkage crack reduces the applicability of the building. Therefore, it is very important to analyze the mechanism of dry-shrinkage deformation of frame masonry filled wall, and to study effective crack control measures. Finite element simulation is mainly used to investigate the crack of frame masonry filled wall structure, to study the mechanism of wall material shrinkage, to test wall material dry shrinkage, and to simulate the crack of frame masonry filled wall by separate finite element method. The research work on crack control measures of frame masonry filled wall and crack control of open-hole frame filled wall has obtained the following main research results:. 1. Considering the influence of the pressure difference inside and outside the interface, the improved Young's relation is derived. The research results can better explain the natural physical phenomenon that the infiltration angle varies with the pressure difference inside and outside the liquid surface. 2. The formulas for calculating the radial stress change of the wall of the uniform pore size and the reduced aperture smooth capillary structure during water evaporation are derived. The conclusion is drawn that the smooth capillary structure expands in the process of water evaporation, and the theoretical model of capillary tension is put forward, and the formulas for calculating radial and axial deformation of capillary structure in the process of capillary water loss are derived. 3. The separated finite element model of frame masonry infilled wall structure is established, and the wall length, frame stiffness, gray joint tensile strength, boundary conditions and construction measures are quantitatively analyzed. Effect of dry shrinkage rate on crack appearance and crack width in different parts of filled wall. 4. Based on the separated finite element model and the dry shrinkage test results of block, the crack control effect of various crack control measures is quantitatively analyzed, and the wall length limit based on crack control of frame-filled wall is given.
【学位授予单位】：浙江大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TU398

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