碳纤维布加固破损RC梁抗弯性能试验研究及有限元分析

发布时间：2018-01-30 05:06

本文关键词： 碳纤维加固少筋梁适筋梁超筋梁有限元　出处：《武汉理工大学》2013年硕士论文　论文类型：学位论文

【摘要】：钢筋混凝土结构在工作期间常常会受到不同程度的损伤,造成其承载能力、刚度、稳定性不断下降,使得建筑物产生大量安全隐患。所以,对现有损伤钢筋混凝土结构进行补强加固已经成为建筑行业的一个新热点。碳纤维材料作为一种新型材料,由于其具有自重轻、耐久性好、抗拉强度高、施工方便快捷等优点,被广泛应用在工业和民用建筑加固中。近年来,我国对碳纤维布加固旧有建筑损伤房屋进行了大量的试验研究,加固的技术水平和施工工艺取得了突破性发展。在钢筋混凝土结构中梁作为建筑结构的重要构件,有着举足轻重的作用,但梁在使用过程中会由于各种原因受到不同程度的损伤和破坏。但目前对超过承载能力的梁加固研究还很少。本试验探索研究了碳纤维布片材加固达到承载力水平的钢筋混凝土梁的抗弯性能。一共选取了12根矩形梁进行分析研究：少筋梁、适筋梁、超筋梁各4根,其中,9根钢筋混凝土梁为预先加载到构件破坏再用碳纤维布加固,3根梁采用未受损直接加固的方法。通过对少筋梁、适筋梁和超筋梁碳纤维布加固研究,考察损伤程度、配筋率、粘贴不同层数的碳纤维布和不同宽度的环箍对加固效果的影响。通过对试验的数据分析、理论分析和有限元计算分析,最终试验结果表明：1、无论是少筋梁、适筋梁还是超级梁,在构件超过极限承载能力后用碳纤维布加固都能使梁恢复到原有的极限承载能力；2、破损加固时粘贴一层与两层碳纤维布对梁极限承载能力和变形能力有所改善,但改善效果随着配筋率的提高而降低；3、环箍宽度对加固效果基本没有影响；4、粘贴碳纤维布加固破损梁对于梁弹性阶段的刚度、开裂荷载和裂缝限制效果不明显,但碳纤维布在加载后期可以有效抑制裂缝发展,提高梁的抗弯刚度；5、采用有限元程序ANSYS对碳纤维布加固钢筋混凝土梁和未加固梁进行了非线性有限元数值模拟计算,计算得极限承载能力与试验结果基本吻合。最后,总结了本文所做的研究成果并提出了进一步的工作展望。本文的研究成果对碳纤维布加固破损梁的合理设计具有一定的指导意义和参考价值。
[Abstract]:Reinforced concrete structures are often damaged in varying degrees during the work, resulting in its bearing capacity, stiffness, stability decline, making the building a large number of safety risks. Reinforcement of existing damaged reinforced concrete structures has become a new hot spot in the construction industry. As a new material, carbon fiber material has light weight, good durability and high tensile strength. In recent years, a large number of experiments have been carried out in China to strengthen damaged buildings with carbon fiber sheets. The technical level and construction technology of reinforcement have made a breakthrough development, in the reinforced concrete structure, beam as an important component of the building structure, plays a pivotal role. However, in the process of use, beams will be damaged and destroyed to varying degrees due to various reasons, but at present, there are few researches on the reinforcement of beams that exceed the bearing capacity. In this experiment, the flexural behavior of reinforced concrete beams strengthened with CFRP sheets was studied. Twelve rectangular beams were selected for analysis: four beams with less reinforcement, four beams with appropriate reinforcement and four beams with extra reinforcement. Among them, 9 reinforced concrete beams are pre-loaded and then strengthened with CFRP sheets. The method of direct strengthening without damage is adopted in 3 beams. The study of CFRP reinforcement with less reinforcement beams, suitably reinforced beams and superreinforced beams is carried out. The effects of damage degree, reinforcement ratio, carbon fiber sheets with different layers and hoops of different widths on the reinforcement effect were investigated. Through the data analysis, theoretical analysis and finite element analysis of the test, the final test results show that: 1, no matter it is a small reinforcement beam, a suitable reinforced beam or a super beam. After the ultimate bearing capacity of the member is exceeded, the beam can be restored to the original limit bearing capacity when strengthened with carbon fiber sheet. (2) the ultimate bearing capacity and deformation capacity of the beam are improved by sticking one layer and two layers of carbon fiber cloth, but the improvement effect decreases with the increase of reinforcement ratio. 3, the width of hoop has no effect on the reinforcement effect; 4. The stiffness, crack load and crack limitation of the damaged beams strengthened with CFRP sheets are not obvious in the elastic stage, but the CFRP sheets can effectively restrain the crack development and improve the flexural stiffness of the beams at the later loading stage. 5. The nonlinear finite element numerical simulation of reinforced concrete beams and unstrengthened beams strengthened with CFRP sheets is carried out by using the finite element program ANSYS, and the ultimate bearing capacity is in good agreement with the experimental results. Finally, the research results of this paper are summarized and the prospect of further work is put forward. The research results of this paper have certain guiding significance and reference value for the reasonable design of CFRP strengthened damaged beams.
【学位授予单位】：武汉理工大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU375.1

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