外贴FRP加固钢筋混凝土梁的有限元分析

发布时间：2018-07-31 11:05

【摘要】：为满足既有钢筋混凝土建筑的安全和使用功能要求,混凝土结构加固技术得到了广泛的关注。钢筋混凝土构件外贴纤维复合材料加固方法以其施工方便、安全耐用、加固效果好等优点在实际的加固工程中得到了广泛应用。但加固后钢筋混凝土梁的二次受力、纤维-混凝土粘结滑移、极限状态受力性能等问题成为人们日益关注并致力研究的焦点。本文采用理论分析和数值模拟手段对外贴纤维加固的钢筋混凝土梁的极限承载力进行了分析,并基于纤维-混凝土粘结滑移关系对纤维层数、配筋率的影响进行探讨,主要内容如下:1.汇总了外贴纤维加固钢筋混凝土梁滞后应变的计算方法。对比分析了各国规范在考虑二次受力情况下加固混凝土梁的计算公式,并给出了滞后应变的简便计算程序。2.考虑二次受力对外贴纤维加固钢筋混凝土梁承载力的影响,对其受力全过程进行了数值分析,结果表明:初始弯矩的存在降低了加固梁的屈服承载力和极限承载力,数值计算结果与文献实验结果吻合较好。3.基于芳纶纤维-混凝土粘结滑移关系,考虑粘结层数,配筋率影响因素,对外贴芳纶纤维加固钢筋混凝土梁的受力性能进行数值计算,给出外贴纤维的最优粘结层数;加固梁的承载力随着粘结层数的增加而增加,但不是线性增加;在粘结层数相同的情况下,混凝土梁的配筋率较低时,纤维布能更好的的发挥作用,使加固梁的承载力大幅度提高。
[Abstract]:In order to meet the safety and functional requirements of existing reinforced concrete buildings, the reinforcement technology of concrete structures has received extensive attention. The reinforcement method of reinforced concrete members is widely used in practical engineering because of its advantages such as convenient construction, safety and durability, good reinforcement effect and so on. However, the problems such as the secondary force of reinforced concrete beam, the bond slip between fiber and concrete, and the ultimate behavior of the reinforced concrete beam have become the focus of attention and research. In this paper, theoretical analysis and numerical simulation are used to analyze the ultimate bearing capacity of reinforced concrete beams strengthened with externally bonded fibers, and based on the relationship between fiber and concrete bond-slip, the influence of fiber layer number and reinforcement ratio is discussed. The main content is as follows: 1. The calculation method of lag strain of reinforced concrete beams strengthened with external fiber is summarized. This paper compares and analyzes the calculation formulas of concrete beams strengthened by national codes under the condition of considering the secondary force, and gives a simple calculation program of hysteresis strain. Considering the influence of secondary force on the bearing capacity of reinforced concrete beams strengthened with external affixed fibers, the whole process of the reinforced concrete beams is numerically analyzed. The results show that the existence of initial bending moment reduces the yield bearing capacity and ultimate bearing capacity of strengthened beams. The numerical results are in good agreement with the experimental results. Based on the bond slip relationship between aramid fiber and concrete, considering the influence factors of bond layer number and reinforcement ratio, the mechanical properties of reinforced concrete beams strengthened with aramid fiber are calculated numerically, and the optimal number of bonding layers is given. The bearing capacity of the strengthened beam increases with the increase of the number of bonding layers, but not linearly. When the reinforcement ratio of the concrete beam is low, the fiber cloth can play a better role when the number of bonding layers is the same. The bearing capacity of the strengthened beam is greatly increased.
【学位授予单位】：哈尔滨工程大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU375.1

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