本文關(guān)鍵詞： 端錨 混錨 薄板 混凝土梁 加固 預(yù)應(yīng)力　出處：《中南大學(xué)》2013年碩士論文　論文類型：學(xué)位論文

【摘要】：摘要：鋼板、FRP片材等薄板已被廣泛應(yīng)用于對(duì)既有結(jié)構(gòu)的加固工程中。通常采用結(jié)構(gòu)膠將薄板粘貼在受彎構(gòu)件受拉區(qū)。這種做法雖然施工方便,但容易發(fā)生剝離破壞,這被視為該加固技術(shù)的致命缺陷。薄板端部剝離緣于該處的應(yīng)力集中。為了降低對(duì)粘膠材料性能和粘貼施工質(zhì)量的依賴性,將薄板按傳統(tǒng)工藝沿全長(zhǎng)粘貼的同時(shí),可在其端部附加機(jī)械錨固裝置,這種錨固方式不妨簡(jiǎn)稱為混錨。與純粘貼薄板端部縱向正應(yīng)力為零、界面剪應(yīng)力高度集中具有本質(zhì)不同,混錨薄板端部可以承擔(dān)很大的縱向拉力,剪應(yīng)力集中現(xiàn)象也能得到大大緩解,故對(duì)抵抗端部剝離十分有利。若在粘貼或粘膠固化之前給薄板施加預(yù)應(yīng)力,即形成預(yù)應(yīng)力混錨系統(tǒng),可望有效解決常規(guī)粘貼所不能解決的裂縫控制問(wèn)題。本文的工作包含以下兩點(diǎn)。 1、進(jìn)行了混錨薄板加固梁的理論分析,推導(dǎo)了混錨薄板加固梁彈性階段的界面正應(yīng)力和剪應(yīng)力的公式。利用有限元軟件對(duì)被混錨薄板加固混凝土梁進(jìn)行了數(shù)值分析。進(jìn)行了理論解、有限元解和試驗(yàn)值的對(duì)比,三者吻合較好,證明了理論公式的正確性以及有限元模型的準(zhǔn)確性。根據(jù)公式、有限元解及試驗(yàn)值,得出混錨系統(tǒng)能夠有效緩解界面應(yīng)力集中的結(jié)論。 2、利用有限元軟件對(duì)混錨薄板預(yù)應(yīng)力加固的混凝土梁進(jìn)行了非線性全過(guò)程模擬。得到了預(yù)應(yīng)力反拱值、開(kāi)裂荷載、屈服荷載等,繪制了荷載-撓度曲線,并與試驗(yàn)梁的結(jié)果進(jìn)行了對(duì)比,誤差在合理范圍內(nèi)。有限元解與試驗(yàn)結(jié)果均表明施加預(yù)應(yīng)力可以有效延遲開(kāi)裂并提高被加固梁的承載力。 本研究的意義在于對(duì)混錨薄板抗彎加固梁首次推導(dǎo)了界面應(yīng)力解答,建立了合理的有限元模型,能夠較準(zhǔn)確地預(yù)測(cè)剝離荷載及承載力等,對(duì)加固設(shè)計(jì)和相關(guān)研究具有參考價(jià)值。
[Abstract]:Absrtact: FRP sheet has been widely used in the reinforcement of existing structures. Usually, the sheet is bonded to the tensile zone of the flexural members by structural glue. This method is convenient in construction. But it is easy to peel and destroy, which is regarded as the fatal defect of the reinforcement technology. The end peeling of thin plate is due to the stress concentration. In order to reduce the dependence on the properties of viscose material and the construction quality of bonding. The mechanical anchoring device can be added to the end of the thin plate while sticking along the full length of the plate according to the traditional technology. This kind of anchoring method may be referred to as mixed anchor for short. The longitudinal normal stress of the end part of the pure adhesive thin plate is zero. The high concentration of interfacial shear stress is essentially different, the end of the mixed anchor plate can bear a large longitudinal tensile force, and the phenomenon of shear stress concentration can be greatly alleviated. Therefore, it is very advantageous to resist peeling. If prestress is applied to the thin plate before bonding or viscose solidification, the prestressing mixed anchor system will be formed. It is expected that the problem of crack control which can not be solved by conventional pasting can be effectively solved. The work of this paper includes the following two points. 1. The theoretical analysis of composite anchor thin plate strengthened beam is carried out. The formulas of interface normal stress and shear stress in elastic stage of concrete beams strengthened with mixed anchor thin plates are deduced. The numerical analysis of concrete beams strengthened with mixed anchor thin plates is carried out by using finite element software, and the theoretical solution is given. The comparison between the finite element solution and the experimental value shows that the theoretical formula is correct and the finite element model is accurate. According to the formula, the finite element solution and the test value. It is concluded that the interfacial stress concentration can be effectively alleviated by the mixed anchor system. 2. The nonlinear whole process simulation of concrete beam strengthened by prestressed concrete with mixed anchor thin plate is carried out by using finite element software. The prestressed inverse arch value, cracking load, yield load and so on are obtained, and the load-deflection curve is drawn. The finite element solution and test results show that the prestressing force can delay cracking and improve the bearing capacity of strengthened beams. The significance of this study is that the interface stress solution is derived for the first time, and a reasonable finite element model is established, which can accurately predict the peeling load and bearing capacity and so on. It has reference value for reinforcement design and related research.
【學(xué)位授予單位】：中南大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2013
【分類號(hào)】：TU375.1

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本文編號(hào)：1456720