二次受力下BFRP加固RC连续梁抗弯能力的研究

发布时间：2018-04-18 19:06

本文选题：二次受力 + 玄武岩纤维布　；参考：《吉林建筑大学》2016年硕士论文

【摘要】：随着混凝土结构长期经受自然环境以及社会环境的侵蚀,其性能也会逐渐降低,这也是自然规律的作用。基于此,如何有效地延缓结构的损伤进程,延长使用寿命,成为结构加固领域关注的热点。玄武岩纤维复合材料(Basalt Fiber Reinforced Polymer/Plastic,简称BFRP)作为一种新型的加固补强材料,凭借其高强度、高模量、耐高温以及化学性质稳定等特点成为继玻璃纤维和碳纤维之后又一种比较热门的纤维材料。二次受力本身是不容忽视的影响因素,目前国内外对二次受力下玄武岩纤维加固钢筋混凝土连续梁的研究相对较少,即便是考虑二次受力的影响,项目研究也多集中于对简支梁的加固。本文通过对11根双跨连续梁的研究,针对不同初始荷载、不同BFRP布层数组成多种工况,根据弹塑性理论知识以及混凝土非线性分析,得出二次受力下BFRP布加固钢筋混凝土连续梁的受弯全过程计算分析,并结合ABAQUS有限元软件进行模拟分析验证其准确性。主要研究内容如下:通过弹塑性理论推导得出二次受力下BFRP加固钢筋混凝土连续梁在受弯过程中受拉区混凝土开裂前、开裂时,受压区混凝土处于弹性阶段、弹塑性阶段的理论计算公式;研究二次受力下BFRP加固钢筋混凝土连续梁受弯破坏模式,并对BFRP布层数给出合理化建议;通过理论计算得出二次受力及BFRP布层数对钢筋混凝土连续梁屈服荷载、极限荷载、挠度的影响,同时运用ABAQUS有限元软件对二次受力下BFRP布加固钢筋混凝土连续梁进行软件模拟分析验证其正确性;通过计算观察钢筋与BFRP布的应变,得出随着BFRP布层数增加,钢筋与BFRP布的应变均相应减小;对于有二次受力的加固梁,二次受力越明显,钢筋应变越大,BFRP布的滞后应变越明显。
[Abstract]:With the erosion of natural environment and social environment for a long time, the performance of concrete structure will decrease gradually, which is also the function of natural law.Based on this, how to effectively delay the damage process and prolong the service life of the structure has become the focus of attention in the field of structural strengthening.Basalt Fiber Reinforced Polymer / Plastics (BFRP) is a new type of reinforcement material, with its high strength and high modulus.The characteristics of high temperature resistance and chemical stability have become a hot fiber material after fiberglass and carbon fiber.The secondary force itself is an influential factor that can not be ignored. At present, there are relatively few researches on the reinforcement of reinforced concrete continuous beams strengthened by basalt fiber under secondary loading at home and abroad, even if the influence of secondary force is taken into account.Project research also focuses on the reinforcement of simply supported beams.In this paper, 11 double-span continuous beams are studied. According to different initial loads and different BFRP layers, there are many kinds of working conditions. According to the theory of elastic-plastic theory and nonlinear analysis of concrete,The calculation and analysis of the whole bending process of reinforced concrete continuous beams strengthened with BFRP sheets under secondary loading are obtained, and the accuracy is verified by the simulation analysis of ABAQUS finite element software.The main research contents are as follows: through the elastoplastic theory derivation, it is concluded that the concrete in the compression zone is in the elastic stage before the crack of the concrete in the tensile zone during the flexural process of the reinforced concrete continuous beam strengthened by BFRP under the secondary stress.The theoretical calculation formula of elastic-plastic stage, the flexural failure mode of reinforced concrete continuous beam strengthened by BFRP under secondary force, and the rational suggestions on the number of layers of BFRP are given.Through theoretical calculation, the influence of secondary force and BFRP layer number on yield load, ultimate load and deflection of reinforced concrete continuous beam is obtained.At the same time, the ABAQUS finite element software is used to simulate and verify the correctness of the reinforced concrete continuous beam strengthened by BFRP cloth under secondary stress, and the strain of reinforcing bar and BFRP cloth is observed by calculating and observing the strain of the steel bar and BFRP cloth, and the results show that the number of layers increases with the increase of BFRP layer.The strain of steel bar and BFRP cloth is reduced correspondingly, and the more obvious the secondary stress is, the more obvious the lag strain of reinforced bar is.
【学位授予单位】：吉林建筑大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TU375.1

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