FRP加固带裂缝木梁弯曲性能研究

发布时间：2018-01-15 14:20

本文关键词：FRP加固带裂缝木梁弯曲性能研究　出处：《上海大学》2013年硕士论文　论文类型：学位论文

【摘要】：木结构是我国、日本及北美等国家的主要传统建筑结构形式之一，由于木材本身易开裂，现存木构件中有相当大的一部分具有裂纹，甚至是贯穿性裂缝，亟需加固维护。与传统的木结构加固方法相比，使用纤维增强聚合物复合材料（FRP）加固木结构具有更多的优势，也具有更广泛的应用前景，值得进一步深化研究。本文对具有纵向贯穿裂缝矩形截面木梁FRP布加固后的弯曲性能进行了理论建模、解析求解和参数研究，得到了一些结果，主要工作如下： 1.对具有纵向贯穿裂缝的矩形截面木梁，采用四周粘贴FRP布的方式加固，考虑FRP布加固层拉伸与压缩时的不同弹性模量，基于组合梁小挠度变形的假定下，首先建立了四周粘贴FRP布加固带纵向贯穿裂缝矩形截面木梁弯曲变形的控制方程。指出当FRP布剪切模量趋于无穷或零时，该控制方程分别退化为四周粘贴FRP布加固完整无裂缝木梁和叠木梁弯曲变形的控制方程。在此基础上，研究了FRP布加固简支木梁在均布荷载作用下的弯曲行为，给出了问题的解析解，考察了材料、几何参数和加固方式等因素对加固木梁弯曲变形的影响。 2.基于前面FRP布加固带纵向贯穿裂缝木梁弯曲变形的控制方程，研究了两集中荷载作用下FRP布加固带裂缝简支木梁的弯曲变形，利用分段函数，，连续条件和边界条件，得到加固木梁弯曲挠度的解析解。验证了解析解的可靠性和适用性，进行了参数分析研究。 3.研究了四周粘贴FRP布加固带纵向贯穿裂缝矩形截面简支木柱在偏心压力作用下的压弯问题，建立了FRP布加固带纵向贯穿裂缝木柱压缩与弯曲组合变形的控制方程。研究了FRP加固简支木柱在一端偏心力作用下的变形，得到了FRP加固木柱轴向位移及弯曲挠度的解析表达式，并考察了材料、几何参数、加固方式和受压荷载偏心距等对FRP加固简支木柱弯曲变形的影响。 4.研究了四周粘贴FRP布加固完整无裂缝简支木柱的偏心受压弯曲，得到了问题的解析解，考察了FRP布的弹性模量、加固方式、加固厚度以及木柱长细比等因素对FRP布加固完整木柱挠度的影响。
[Abstract]:Wood structure is one of the main traditional building structures in China, Japan and North America. Due to the easy cracking of wood itself, a large part of the existing wood members have cracks, even penetrating cracks. Compared with the traditional method of strengthening wood structure, FRP-based fiber reinforced polymer composite (FRP) has more advantages and has a wider application prospect. It is worth further study. In this paper, the flexural behavior of rectangular beams reinforced by FRP sheets with longitudinal penetrating cracks is modeled, solved analytically and parameters studied, and some results are obtained. The main tasks are as follows: 1. The rectangular cross-section wooden beams with longitudinal cracks are strengthened with FRP sheets, and the different elastic moduli of the layers strengthened with FRP sheets are considered. Based on the assumption of small deflection deformation of composite beam. First, the governing equations of bending deformation of rectangular beams with longitudinal penetrating cracks strengthened with FRP sheets are established, and it is pointed out that when the shear modulus of FRP sheets tends to infinity or 00:00. The governing equations are reduced to the governing equations of bending and deformation of intact cracked wood beams and laminated beams strengthened with FRP sheets respectively. The bending behavior of simply supported timber beams strengthened with FRP sheets under uniform load is studied. The analytical solution is given. The effects of materials, geometric parameters and reinforcement methods on the bending deformation of the strengthened timber beams are investigated. 2. Based on the governing equation of the bending deformation of the longitudinal perforated beams strengthened with FRP sheets in front, the bending deformation of simply supported beams with cracks strengthened by FRP sheets under two concentrated loads is studied, and the piecewise function is used. The analytical solution of the bending deflection of the strengthened wood beam is obtained under the continuous condition and the boundary condition. The reliability and applicability of the analytical solution are verified and the parameter analysis is carried out. 3. The compression and bending of simply supported columns with longitudinal perforated rectangular section strengthened with FRP sheets under eccentric pressure are studied. The governing equations of the compression and bending combined deformation of the longitudinal perforated timber columns strengthened with FRP sheets are established. The deformation of simply supported columns strengthened with FRP under the action of eccentric force at one end is studied. The analytical expressions of axial displacement and bending deflection of FRP strengthened timber columns are obtained. The effects of materials, geometric parameters, reinforcement methods and eccentricity of compression load on the bending deformation of simply supported timber columns strengthened with FRP are investigated. 4. The eccentricity bending of intact simply supported columns without cracks strengthened with FRP sheets is studied, the analytical solution of the problems is obtained, and the elastic modulus and reinforcement mode of FRP sheets are investigated. The effect of strengthening thickness and the ratio of length to slenderness on the deflection of the whole column strengthened with FRP cloth.
【学位授予单位】：上海大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU366.2

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