本文選題：表面內(nèi)嵌　切入點：FRP筋　出處：《沈陽建筑大學》2015年碩士論文　論文類型：學位論文

【摘要】：當建筑結(jié)構(gòu)在承載能力或者使用功能無法繼續(xù)滿足正常使用的要求時,不可避免地將面對加固問題。FRP筋作為一種新型的復合材料,具有良好的受力性能和耐久性,表面內(nèi)嵌FRP筋加固技術(shù)已逐漸成為混凝土結(jié)構(gòu)加固領(lǐng)域的研究熱點。表面內(nèi)嵌FRP筋與粘結(jié)劑之間的粘結(jié)性能是FRP筋結(jié)構(gòu)中最基本的力學行為,是設(shè)計、應(yīng)用和推廣該種加固方法的關(guān)鍵技術(shù)之一。本課題通過研究表面內(nèi)嵌FRP筋混凝土的粘結(jié)滑移性能,期望為表面內(nèi)嵌FRP筋加固技術(shù)的研究與應(yīng)用提供一定的參考依據(jù)。本文通過對一組表面內(nèi)嵌FRP筋混凝土拉拔試件進行試驗分析,研究試件的受力形式和破壞模式,對FRP筋直徑d、粘結(jié)長度l和FRP筋類型等影響因素進行分析。試驗表明,試件的破壞模式表現(xiàn)為FRP筋與結(jié)構(gòu)膠界面破壞、結(jié)構(gòu)膠與混凝土界面剝離、FRP筋被拉斷和結(jié)構(gòu)膠劈裂四種。通過分析影響因素發(fā)現(xiàn),在粘結(jié)長度不變的情況下,d=8mm的試件的最大粘結(jié)應(yīng)力均大于d=10mm的試件；在直徑相同的情況下,BFRP筋試件的最大粘結(jié)應(yīng)力隨粘結(jié)長度的增加而增大,GFRP筋試件的最大粘結(jié)應(yīng)力隨粘結(jié)長度的增加而減��；在粘結(jié)長度和FRP筋直徑均相同的情況下,GFRP筋試件的最大粘結(jié)應(yīng)力大于BFRP筋試件。通過對試驗曲線進行分析擬合,建立了一種適用于表面內(nèi)嵌FRP筋與混凝土粘結(jié)性能的粘結(jié)-滑移本構(gòu)關(guān)系模型。該模擬能夠較為準確地模擬兩者之間粘結(jié)滑移性能。在此基礎(chǔ)上,推導了表面內(nèi)嵌FRP筋錨固長度限值的計算公式。利用有限元分析軟件對表面內(nèi)嵌FRP筋混凝土拉拔試驗進行數(shù)值模擬。將有限元分析結(jié)果與試驗結(jié)果進行分析對比,曲線吻合良好,驗證了有限元模型的正確性。在此基礎(chǔ)上,對粘結(jié)區(qū)域FRP筋的應(yīng)變和粘結(jié)應(yīng)力分布曲線進行分析。通過對一組表面內(nèi)嵌FRP筋加固混凝土梁試件進行梁式試驗,研究FRP筋加固混凝土梁的受力形式和破壞模式,對FRP筋直徑d、粘結(jié)長度l和FRP筋類型等影響因素進行分析。試驗表明試件的破壞模式為：結(jié)構(gòu)膠整體破壞、粘結(jié)區(qū)域結(jié)構(gòu)膠剝離破壞、和FRP筋被拉斷三種。通過對影響因素分析發(fā)現(xiàn),在粘結(jié)長度不變的情況下,d=8mm的試件的極限荷載均小于d=10mm的試件；在FRP筋直徑相同的情況下,當粘結(jié)長度不大于400mm時,試件的極限荷載隨粘結(jié)長度的增加而增大,當粘結(jié)長度大于400mmm時,試件的最大粘結(jié)應(yīng)力隨粘結(jié)長度的增加而減小；在粘結(jié)長度和FRP筋直徑均相同的情況下,當粘結(jié)長度不大于200mm時,GFRP筋試件的極限荷載大于BFRP筋試件,當粘結(jié)長度大于200mmm時,GFRP筋試件的極限荷載小于BFRP筋試件。
[Abstract]:When the carrying capacity or function of building structure can not meet the requirements of normal use, it is inevitable to take the reinforcement problem as a new type of composite material, which has good mechanical performance and durability. The surface FRP reinforcement technology has gradually become the research hotspot in the field of concrete structure strengthening. The bond behavior between the surface embedded FRP reinforcement and the binder is the most basic mechanical behavior and the design of the FRP reinforcement structure. One of the key techniques for applying and popularizing this method is to study the bond-slip behavior of FRP reinforced concrete embedded in the surface. It is expected to provide a certain reference for the study and application of the strengthening technology of surface embedded FRP bars. Through the experimental analysis of a group of concrete drawing specimens with FRP tendons embedded in the surface, the force form and failure mode of the specimens are studied. The influence factors such as diameter d of FRP bar, length of bond l and type of FRP bar are analyzed. The test results show that the failure mode of the specimen is the interface failure of FRP bar and structural glue. There are four kinds of FRP bars at the interface between structural adhesive and concrete. Through the analysis of the influencing factors, it is found that the maximum bond stress of the specimen with 8 mm is higher than that of the specimen with 10 mm. Under the same diameter, the maximum bond stress of BFRP bars increases with the increase of bond length, and the maximum bond stress of GFRP bars decreases with the increase of bond length. Under the same bond length and diameter, the maximum bond stress of the specimens with FRP tendons is larger than that of BFRP tendons. A bond-slip constitutive model suitable for the bond behavior of FRP bars and concrete embedded on the surface is established. The simulation can accurately simulate the bond-slip behavior between the two. In this paper, the formula for calculating the limit of anchoring length of FRP reinforcement embedded on the surface is derived. The drawing test of FRP reinforced concrete on the surface is numerically simulated by using the finite element analysis software. The results of finite element analysis are compared with those of the test. The curve agrees well, which verifies the correctness of the finite element model. On this basis, the distribution curves of strain and bond stress of FRP tendons in the bond region are analyzed. The beam tests are carried out on a group of concrete beam specimens strengthened with FRP tendons embedded in the surface. The stress forms and failure modes of concrete beams strengthened with FRP bars are studied. The influence factors such as diameter d of FRP tendons, bond length l and type of FRP bars are analyzed. The test results show that the failure modes of the specimens are as follows: structural adhesive failure. There are three kinds of structural adhesive debonding failure in the bond area and tensile fracture of the FRP tendons. Through the analysis of the influencing factors, it is found that the ultimate load of the specimens with 8 mm of bond length is smaller than that of the specimens with the same diameter of the FRP tendons, and the ultimate load of the specimens with the same diameter of the FRP bars is less than that of the specimens with the same diameter of the FRP bars. When the bond length is less than 400 mm, the ultimate load of the specimen increases with the increase of the bond length, and the maximum bond stress decreases with the increase of the bond length when the bond length is greater than 400 mm. When the bonding length and the diameter of FRP tendons are the same, when the bonding length is not more than 200mm, the ultimate load of GFRP-reinforced specimens is larger than that of BFRP tendons, and the ultimate load of GFRP-reinforced specimens is smaller than that of BFRP tendons when the bonding length is more than 200mmm.
【學位授予單位】：沈陽建筑大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TU377

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