玄武岩纤维布加固钢筋混凝土T型梁力学性能数值分析

发布时间：2018-09-04 17:17

【摘要】：玄武岩纤维(BFRP)复合材料是一种新型复合材料,具有强度高、耐腐蚀、耐高温、良好的延伸率以及价格低廉等优点,当前越来越受到国内外专家学者的青睐。本文基于试验研究与有限元数值分析理论对玄武岩纤维布加固钢筋混凝土T型梁的受弯性能进行了数值分析,以期为工程应用提供依据。本文采用ABAQUS有限元数值分析软件,结合损伤断裂原理,对BFRP加固钢筋混凝土T型梁加固后力学性能进行了数值分析与验证。采用了内聚力模型的损伤和开裂行为来模拟粘接界面,通过有限元数值结果与试验结果的对比,验证了有限元模型的合理性,并进一步研究了翼缘高度、配筋率、弹性模量、粘贴层数、U型箍布置情况和二次受力情况等主要因素对加固效果的影响。有限元分析结果表明:试验工况下,武岩纤维布加固钢筋混凝土T型梁粘接胶层没有发生破坏,能够有效传递混凝土梁与玄武岩纤维布之间的应力;加固翼缘较高的T型梁,承载力提高较多,加固效果更为明显;玄武岩纤维布适用于加固配筋率相对较低的适筋梁,配筋率较高时加固效果不明显;弹性模量较高的玄武岩纤维布能够提高截面的极限承载力,不过会降低截面延性;增加U型箍可以提高截面抗剪能力,改善加固效果;二次受力情况的结构加固效果会由于初始负荷的增加而降低,同时延性也会相应降低。本文结合有限元数值分析结果与已有试验研究结果,分析了对BFRP加固钢筋混凝土T型梁加固效果起主要作用的影响因素,提出较为经济合理的玄武岩纤维布加固方式,总结出工程加固方案与设计方法建议,为实际工程应用提供一定的参考。本文的创新点:以试验为基础,采用数值分析的方法,分析了加固梁在各种影响因素下的破坏模式;选用界面单元模拟了玄武岩纤维布与钢筋混凝土之间的粘接胶层;数值模拟了在二次受力情况下,玄武岩纤维布的加固效果。
[Abstract]:Basalt fiber (BFRP) composite is a new type of composite material, which has the advantages of high strength, corrosion resistance, high temperature resistance, good elongation and low price, etc. At present, it is more and more favored by experts and scholars at home and abroad. Based on the experimental study and finite element numerical analysis theory, the flexural behavior of reinforced concrete T-beam strengthened with basalt fiber sheet is analyzed numerically in this paper, in order to provide the basis for engineering application. In this paper, the mechanical properties of reinforced concrete T-beam strengthened by BFRP are numerically analyzed and verified by using the finite element analysis software ABAQUS and the principle of damage and fracture. The damage and cracking behavior of cohesive force model is used to simulate the bonding interface. The rationality of the finite element model is verified by comparing the finite element numerical results with the experimental results, and the flange height, reinforcement ratio and elastic modulus are further studied. The influence of main factors, such as the arrangement of U type hoop and the secondary force, on the reinforcement effect. The results of finite element analysis show that the adhesive layer of reinforced concrete T-beam strengthened with Wuyan fiber sheet has not been destroyed, and the stress between concrete beam and basalt fiber cloth can be transferred effectively, and the T-beam with high flange can be strengthened. The bearing capacity is improved more, the reinforcement effect is more obvious, the basalt fiber cloth is suitable for the reinforcement beam with relatively low reinforcement ratio, but the reinforcement effect is not obvious when the reinforcement ratio is high. The high elastic modulus of basalt fiber cloth can increase the ultimate bearing capacity of the section, but reduce the ductility of the section, increase the U type hoop can improve the shear capacity of the section and improve the reinforcement effect. The reinforcement effect of the secondary load will decrease with the increase of the initial load, and the ductility will decrease accordingly. Based on the results of finite element numerical analysis and experimental research, this paper analyzes the main influence factors on the reinforcement effect of reinforced concrete T-beam strengthened by BFRP, and puts forward a more economical and reasonable strengthening method of basalt fiber cloth. The suggestion of reinforcement scheme and design method is summarized, which provides some reference for practical engineering application. The innovations of this paper are as follows: based on the experiment, the failure mode of strengthened beams under various influence factors is analyzed by numerical analysis, and the adhesive layer between basalt fiber cloth and reinforced concrete is simulated by interface element. The reinforcement effect of basalt fiber cloth is simulated numerically.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TU375.1

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