宏观裂缝影响下的FRP-混凝土界面粘结-滑移机理研究

发布时间：2018-05-16 02:41

本文选题：FRP-混凝土界面 + 粘结-滑移　；参考：《广东工业大学》2017年硕士论文

【摘要】：纤维增强复合材料(Fiber Reinforced Polymer,简称为FRP)在土木工程中的应用越来越广泛。在实际工程中,常常遇到需要使用FRP加固的混凝土结构存在宏观裂缝的情况。然而现在对宏观裂缝影响下的FRP-混凝土界面粘结-滑移机理这一问题的研究还比较少,急需研究。本文作者为解决这一难题,对宏观裂缝影响下的FRP-混凝土界面粘结-滑移机理进行了初步研究。本文的主要研究内容和结论如下:(1)通过研读国内外众多研究FRP在土木工程中应用的学者的研究文献,研制了能有效解决加载时使FRP-混凝土界面一直处于纯剪切应力状态这一技术难题的FRP布夹具(钢加载头)并对其进行了有限元分析以验证其满足试验要求,提出了经过优化的双剪加载方案,以保证静载下FRP-混凝土界面双剪试验能顺利进行。(2)在有关研究的基础上,经过理论推导和大量试算,提出了宏观裂缝影响下的FRP-混凝土界面粘结-滑移本构模型。(3)通过FRP-混凝土界面静载试验,对宏观裂缝影响下的FRP-混凝土界面承受静载时的加载过程、破坏过程与破坏形态进行了试验观测,用MATLAB软件编写了相关试验数据的运算程序,研究了宏观裂缝影响下的FRP-混凝土界面的应力传递规律、界面粘结破坏机理、界面滑移的演化规律,并通过对试验数据的拟合和分析,结合MATLAB软件建立了静载下宏观裂缝影响下的FRP-混凝土界面的粘结-滑移本构模型,并与现有的其他研究者提出的相关模型进行了对比。同时,通过对试验数据的运算与比较,对宏观裂缝的影响区域进行了分析。(4)依据试验得出的静载下宏观裂缝影响下的FRP-混凝土界面粘结-滑移本构模型,并结合ABAQUS软件,建立了静载下宏观裂缝影响下的FRP-混凝土界面粘结-滑移本构关系的相关有限元模型,证明了本文提出的模型的有效性、合理性和精确性。同时,通过对静载下宏观裂缝影响下的FRP-混凝土界面粘结-滑移本构关系有限元模型进行分析与对比,研究了宏观裂缝对界面粘结-滑移关系的影响,弥补了通过试验的方法研究宏观裂缝影响下的FRP-混凝土界面粘结-滑移关系时只能得到试件上若干个点的界面粘结-滑移关系而无法直观了解加载过程中混凝土试件各处应变变化情况的不足。(5)通过对宏观裂缝影响下的FRP-混凝土界面粘结-滑移本构关系的试验研究与有限元模型的分析,总结了相应的规律,为在土木工程设计与施工中混凝土结构存在宏观裂缝前提下运用FRP加固混凝土结构提供了相应的设计、施工依据与建议。
[Abstract]:Fiber Reinforced Polymer (FRP) is widely used in civil engineering. In practical engineering, there are often macroscopic cracks in concrete structures which need to be strengthened with FRP. However, there are few researches on the bond-slip mechanism of FRP- concrete interface under the influence of macroscopic cracks. In order to solve this problem, the mechanism of bond-slip at FRP- concrete interface under the influence of macroscopic cracks is studied preliminarily. The main contents and conclusions of this paper are as follows: (1) through the study of many domestic and foreign scholars who study the application of FRP in civil engineering, A FRP fixture (steel loading head), which can effectively solve the technical problem of making the interface of FRP- concrete in pure shear stress state, is developed and analyzed by finite element analysis to verify that it meets the test requirements. An optimized double shear loading scheme is put forward to ensure that the double shear test of FRP- concrete interface can be carried out smoothly under static load. The bond slip constitutive model of FRP- concrete interface under the influence of macroscopic crack is proposed. The loading process of FRP- concrete interface under static load is studied by static load test of FRP- concrete interface under the influence of macroscopic crack. The failure process and failure morphology were observed experimentally, and the calculation program of relevant test data was compiled by MATLAB software. The stress transfer law and bond failure mechanism of FRP-concrete interface under the influence of macroscopic cracks were studied. By fitting and analyzing the experimental data and combining with MATLAB software, the bond slip constitutive model of FRP- concrete interface under static load under macroscopic crack is established. The model is compared with other related models put forward by other researchers. At the same time, through the calculation and comparison of test data, the influence area of macroscopic crack is analyzed. 4) according to the experimental results, the FRP-concrete interface bond slip constitutive model under static load is obtained, and combined with ABAQUS software. The relevant finite element model of the bond slip constitutive relation of FRP- concrete interface under the influence of macroscopic crack under static load is established, and the validity, rationality and accuracy of the proposed model are proved. At the same time, through the analysis and comparison of FRP- concrete interface bond-slip constitutive relation finite element model under the influence of macroscopic crack under static load, the influence of macro crack on interface bond-slip relationship is studied. When the FRP- concrete interface bond-slip relation under the influence of macroscopic crack is studied by the experimental method, only the interface bond-slip relation of several points on the specimen can be obtained, and the concrete under loading process can not be understood intuitively. The deficiency of strain variation in various parts of the specimen. (5) through the experimental study and the finite element model analysis of the bond slip constitutive relation at the interface of FRP- concrete under the influence of macroscopic cracks, The corresponding law is summarized, which provides the corresponding design, construction basis and suggestion for strengthening concrete structure with FRP under the premise of macroscopic cracks in civil engineering design and construction.
【学位授予单位】：广东工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU398.9

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