FRP板加固钢筋混凝土梁的抗剪性能研究

发布时间：2018-06-01 01:43

本文选题：钢筋混凝土梁 + FRP板　；参考：《东北石油大学》2017年硕士论文

【摘要】：Fiber Reinforced Plastic,简称FRP;我国称为纤维增强复合材料,因为优点比较多:密度小、强度大、耐疲劳性好、并且具有强耐腐蚀及不易损坏性、方便实际施工以及对原构件截面尺寸影响极小等特点,从FRP出现到现在为止,世界上很多的专家、学者和工程师对FRP加固钢筋混凝土结构抗弯性能、抗剪性能和抗震性能等做了很大量的试验和研究,并且取得多项研究成果,也已有较多的实际应用,在我国的房建工程中已被逐步运用。但是因为抗剪加固混凝土结构具有很多的影响因素,到现在为止对于抗剪加固钢筋混凝土梁的有关文献相对不多。并且现有的对于FRP加固混凝土梁的试验研究大多数针对侧面粘贴、U型粘贴和全封闭粘贴,对于FRP板部分粘贴或倾斜粘贴的研究较少;并且,我国出的碳纤维片材加固技术规程中的公式也没有区分条形粘贴和全贴、剥离和拉断等因素,关于碳纤维抗剪加固混凝土结构最终承载力的问题,只是把条行粘贴的碳纤维提供的抗剪承载力加上原梁的抗剪承载力,但是碳纤维和原来的钢筋混凝土结构并不是简单的同时达到最大承载力,所以,研究碳纤维抗剪加固混凝土结构承载力的主要问题是研究碳纤维的抗剪贡献。还有,我国的技术规程只是笼统的给出了碳纤维板材的公式,没有区分板和布的区别,对于抗剪加固混凝土结构只是考虑了纤维方向与构件纵向垂直,这造成抗剪计算的最终结果有些偏差,甚至有时候是不安全的。本文利用ABAQUS有限元软件模拟加固了40根钢筋混凝土梁并进行静力分析,研究分析几种因素对承载力的影响。本文共有七种不同的粘贴方式,五组不同的原梁构造,分别分析了混凝土强度、箍筋间距、剪跨比、FRP粘贴形式这四种情况对FRP抗剪加固钢筋混凝土梁承载力的影响。本文主要的内容和研究结果如下:1.根据参考文献,采用正确的混凝土、钢筋和FRP的本构关系,利用ABAQUS软件建立FRP抗剪加固钢筋混凝土梁的有限元模型,完成静力加载分析,并与原文进行比较,提出正确的有限元建模方法。2.改变模拟构件的部分参数,如混凝土强度、箍筋间距、剪跨比、FRP粘贴形式来研究分析各个因素对FRP抗剪加固钢筋混凝土梁最终承载力的大小影响,以此验证各个参数对钢筋混凝土梁开裂荷载、极限荷载、跨中位移和箍筋应变的影响规律。3.基于所获得的荷载-位移曲线,箍筋荷载-应变曲线等数据,通过分析得到影响FRP抗剪加固钢筋混凝土梁的参数,然后进行对比分析,得到这几种参数对抗剪加固的影响,在带入我国碳纤维片材加固技术规程中的公式,与模拟数据对比验证,验证倾斜粘贴的优势,并提出相应系数。
[Abstract]:Fiber Reinforced Plastic, is called fiber reinforced composite in our country because of its many advantages: low density, high strength, good fatigue resistance, strong corrosion resistance and not easy to damage. From the appearance of FRP up to now, many experts, scholars and engineers in the world have studied the flexural behavior of reinforced concrete structures strengthened with FRP. A lot of experiments and researches have been done on the shear and seismic properties, and many research results have been obtained, which have been applied in many practical projects and have been used step by step in the housing construction projects in our country. However, due to the influence of many factors on shear strengthening of concrete structures, there are relatively few literatures on shear strengthening of reinforced concrete beams up to now. And most of the existing experimental studies on FRP strengthened concrete beams are aimed at side bonding and full closed bonding, but there are few researches on partial or oblique bonding of FRP plates. The formulas in the technical specification for CFRP reinforcement in our country also do not distinguish the factors such as strip paste and full sticking, stripping and breaking, etc., concerning the ultimate bearing capacity of concrete structures strengthened by CFRP shear. The shear capacity provided by the bonded carbon fiber is only added to the shear capacity of the original beam, but the carbon fiber and the original reinforced concrete structure do not reach the maximum bearing capacity at the same time, so, The main problem of studying the bearing capacity of CFRP reinforced concrete structure is to study the shear contribution of CFRP. In addition, the technical code of our country only gives the formula of carbon fiber sheet in general terms. There is no difference between sheet and cloth. For shear reinforced concrete structures, the direction of fiber is only considered to be perpendicular to the longitudinal direction of members. This results in some deviations and sometimes unsafe results in shear calculations. In this paper, ABAQUS finite element software is used to simulate the reinforcement of 40 reinforced concrete beams and static analysis is carried out to study the influence of several factors on the bearing capacity. In this paper, there are seven different bonding methods and five groups of different original beam structures. The effects of concrete strength, stirrups spacing and shear span ratio on the bearing capacity of reinforced concrete beams strengthened by FRP are analyzed. The main contents and results of this paper are as follows: 1. According to the reference, using the correct constitutive relation of concrete, steel bar and FRP, the finite element model of reinforced concrete beam strengthened by FRP shear is established by using ABAQUS software, and the static loading analysis is completed and compared with the original text. The correct finite element modeling method. By changing some parameters of simulated members, such as concrete strength, stirrups spacing, shear span ratio and FRP-bonded form, the influence of various factors on ultimate bearing capacity of reinforced concrete beams strengthened with FRP is studied. The effects of various parameters on cracking load, ultimate load, mid-span displacement and stirrups strain of reinforced concrete beams are verified. Based on the data of load-displacement curve and stirrups load-strain curve, the parameters of reinforced concrete beams strengthened with FRP shear are obtained through analysis, and then the effects of these parameters on shear strengthening are obtained. The formulas introduced into the technical specification of CFRP reinforcement in China are compared with the simulated data to verify the advantages of inclined paste and the corresponding coefficients are put forward.
【学位授予单位】：东北石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU375.1

【参考文献】