外贴FRP与混凝土界面的宽度效应和回弹现象研究

发布时间：2018-05-21 10:21

本文选题：FRP粘结混凝土界面 + 宽度效应　；参考：《湖南大学》2015年硕士论文

【摘要】：在最近的二十年里,外贴FRP加固法越来越被广泛地运用于钢筋混凝土结构的加固领域。在外贴FRP加固法中,FRP与混凝土界面之间的剥离破坏是加固的组合梁失效的主要模式,因此FRP与混凝土之间的界面力学行为是FRP加固混凝土技术的基础问题,也是难点问题。其中确定准确的外贴FRP与混凝土界面的宽度效应模型以及解释FRP粘结混凝土单拉试件出现的回弹现象是目前困扰学者们的两大难题。本文前二章从FRP粘结混凝土面内剪切试验的试验方法、破坏模式、剥离承载力模型和粘结滑移关系模型几个方面对先前的文献资料进行了总结,统计了到目前为止学者们提出的剥离承载力模型和粘结滑移关系模型,并对比分析了各个模型之间的优缺点。本文第三章在文献资料的基础上,建立了拥有865个FRP与混凝土面内剪切试件的数据库。利用其中65个拥有FRP二维应变分布场的试验数据,对宽度效应进行了分析。最后在综合考虑FRP材料的弹性模量、厚度、粘结长度、宽度以及混凝土土的抗压强度的影响下,推导了宽度效应模型公式和极限剥离承载力公式,并将新模型与以前的模型以及865个试件的数据库进行对比分析,发现新模型能更好的预测试验数据。本文第四章在考虑回弹现象引起的粘结滑移关系曲线的卸载和重新加载过程后,求解外贴FRP与混凝土单拉试件的平衡微分方程,得到了考虑回弹现象下的单拉试件的理论解,并对单拉试件的回弹现象的发生条件、发展过程和影响区域进行了详细分析。通过理论解与试验数据的对比发现,本文推导的理论解不仅更加符合试验结果,而且本文的理论解还为单拉试件靠近荷载段的应变下降段提供了合理的解释。
[Abstract]:In the last two decades, FRP reinforcement method has been widely used in reinforced concrete structures. The debonding failure between FRP and concrete interface is the main failure mode of reinforced composite beam, so the interface mechanical behavior between FRP and concrete is the basic and difficult problem of FRP strengthening concrete technology. The determination of the exact width effect model of the interface between FRP and concrete and the interpretation of the springback phenomenon of single tensile specimens of FRP bonded concrete are two difficult problems which are puzzling scholars at present. In the first two chapters of this paper, the experimental methods of in-plane shear test of FRP bonded concrete, failure mode, debonding bearing capacity model and bond-slip relationship model are summarized. The peeling capacity model and the bond-slip relationship model proposed by scholars so far are statistically analyzed and the advantages and disadvantages of each model are compared and analyzed. In the third chapter, based on the literature, a database of 865 FRP and in-plane shear specimens is established. In this paper, the width effect is analyzed by using 65 experimental data with FRP two-dimensional strain distribution field. Finally, considering the influence of elastic modulus, thickness, bond length, width and compressive strength of concrete soil, the width effect model formula and ultimate peeling bearing capacity formula are derived. The new model is compared with the previous model and 865 sample databases, and it is found that the new model can better predict the experimental data. In the fourth chapter, after considering the unloading and reloading process of the bond-slip relation curve caused by springback, the equilibrium differential equation between FRP and concrete single tensile specimen is solved, and the theoretical solution of single tensile specimen considering springback is obtained. The conditions, development process and influence area of springback of single tensile specimen are analyzed in detail. By comparing the theoretical solution with the experimental data, it is found that the theoretical solution derived in this paper not only accords with the test results, but also provides a reasonable explanation for the strain descending section near the load section of the single tensile specimen.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU37

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