本文選題：FRP + 抗剪加固��； 參考：《深圳大學(xué)》2015年碩士論文

【摘要】：隨著土木工程領(lǐng)域既有構(gòu)件加固需求的增加,纖維增強(qiáng)復(fù)合材料(Fiber reinforced plastics,簡稱FRP)被廣泛的應(yīng)用于混凝土結(jié)構(gòu)的加固工程。FRP材料具有優(yōu)越的耐腐蝕性、輕質(zhì)高強(qiáng)便于施工和不影響原有結(jié)構(gòu)截面等優(yōu)良性質(zhì),使其成為重要的加固方式,其中FRP應(yīng)用于鋼筋混凝土梁抗剪加固提高既有混凝土梁的抗剪承載力是加固領(lǐng)域的一項重要課題。在FRP抗剪加固混凝土梁性能研究方面,一些學(xué)者進(jìn)行了試驗方面的研究,但由于混凝土梁抗剪性能的復(fù)雜性、試驗條件的限制、試驗者的試驗設(shè)計局限性等原因造成系統(tǒng)的抗剪數(shù)據(jù)依然較少。對于影響加固梁抗剪性能的因素大多還停留在單因素的分析層面,而影響FRP抗剪加固混凝土梁性能的因素往往是協(xié)同作用,相互影響的。將基于試驗的單因素影響規(guī)律進(jìn)行簡單疊加并不能很好的反應(yīng)影響因素對于抗剪性能的影響。伴隨著有限元理論發(fā)展與成熟,以及計算機(jī)軟件和硬件的飛速發(fā)展,使得運用有限元方法分析FRP加固混凝土梁這一復(fù)雜問題成為可能。有限元模擬提供了一種節(jié)約時間、經(jīng)費,不需要考慮試驗的限制的研究方法,可以對影響FRP抗剪加固的因素進(jìn)行有效的分析。本文旨在在混凝土塑性損傷理論的基礎(chǔ)上建立一套適用于FRP抗剪加固混凝土梁模擬的有限元模型,為之后的影響因素分析奠定堅實的基礎(chǔ)。本文選取六種典型的混凝土塑性損傷模型,對所選取模型的受拉損傷因子和受壓損傷因子進(jìn)行了正交分析。并分別進(jìn)行了本構(gòu)模型的橫向分析和縱向分析,受拉損傷因子模型對加固梁的抗剪性能具有重要的影響;而受壓損傷因子模型的定義對抗剪性能的影響有限影響主要體現(xiàn)在極限荷載后下降段的不同;并通過正交分析的結(jié)果選取適用于FRP抗剪加固混凝土梁模擬的混凝土塑性損傷模型。本文建立無腹筋混凝土梁、有腹筋混凝土梁和FRP加固混凝土梁三種有限元模型形成一個模型系統(tǒng),使得模型循序漸進(jìn)并在分析中對三種模型進(jìn)行相互對比。明確了有限元模型在不同類型模型下的規(guī)律并進(jìn)行了不同模型的時程分析。本文對混凝土塑性損傷模型本構(gòu)定義中對抗剪模擬影響較大的擴(kuò)容角和粘性系數(shù)進(jìn)行了參數(shù)分析,明確了其對抗剪模擬的影響規(guī)律并總結(jié)了影響擴(kuò)容角定義的因素。本文同時進(jìn)行了單元尺寸和界面粘結(jié)滑移參數(shù)的參數(shù)分析。確定了單元尺寸對模擬結(jié)果的影響規(guī)律及粘結(jié)滑移模型對界面定義的重要性,并適當(dāng)分析了箍筋與FRP條帶的相互作用。本文所建立的梁模型的剪跨比基本分布于3左右,屬于大剪跨比的混凝土梁。本文之所以選擇這些梁進(jìn)行分析是因為在這一剪跨比附件的試驗數(shù)據(jù)較多并且剪切破壞模式明顯,而小剪跨比梁的破壞模式有明顯的不同不屬于本文的考慮范圍。
[Abstract]:With the increasing demand for reinforcement of existing components in civil engineering field, fiber reinforced plastics (FRPs) are widely used in strengthening concrete structures. FRP materials have excellent corrosion resistance. Lightweight and high strength is convenient for construction and does not affect the original structural cross-section and other excellent properties, making it an important way of reinforcement, The application of FRP to shear strengthening of reinforced concrete beams is an important subject in the field of strengthening. In the research of FRP shear strengthening concrete beams, some scholars have carried out experimental research, but due to the complexity of the shear behavior of concrete beams, the test conditions are limited. Due to the limitation of test design, the shear data of the system are still few. Most of the factors affecting the shear behavior of strengthened beams remain at the level of single factor analysis, while the factors affecting the performance of FRP shear strengthened concrete beams are often synergistic and mutually affected. Simply adding the single factor influence law based on the experiment is not a good way to respond to the influence factors on the shear performance. With the development and maturity of finite element theory and the rapid development of computer software and hardware, it is possible to use finite element method to analyze the complex problem of strengthening concrete beams with FRP. Finite element simulation (FEM) provides a time-saving, cost-saving research method that does not need to consider the limitations of the test, and can effectively analyze the factors affecting the shear strength of FRP. Based on the plastic damage theory of concrete, this paper aims to establish a set of finite element models suitable for the simulation of FRP shear strengthened concrete beams, which will lay a solid foundation for the analysis of the influencing factors in the future. In this paper, six typical plastic damage models of concrete are selected and the tensile damage factors and compressive damage factors of the selected models are analyzed by orthogonal analysis. The transverse analysis and longitudinal analysis of the constitutive model are carried out respectively. The tensile damage factor model has an important effect on the shear behavior of the strengthened beam. However, the definition of compression damage factor model has a limited effect on shear performance, which is mainly reflected in the difference of the descending section after ultimate load. According to the results of orthogonal analysis, the plastic damage model of concrete is selected, which is suitable for FRP shear reinforced concrete beam simulation. In this paper, three finite element models of concrete beams without web reinforcement, concrete beams with web reinforcement and FRP strengthened concrete beams are established to form a model system, which makes the models step by step and compare with each other in the analysis. The law of finite element model under different types of models is clarified and the time history analysis of different models is carried out. In this paper, the expansion angle and viscosity coefficient, which have great influence on shear resistance simulation in the constitutive definition of plastic damage model of concrete, are analyzed, the influence law of shear resistance simulation is clarified and the factors influencing the definition of expansion angle are summarized. At the same time, the parameter analysis of element size and interface bond-slip parameters is carried out. The influence of element size on simulation results and the importance of bond-slip model to the definition of interface are determined, and the interaction between stirrups and FRP strips is properly analyzed. The shear span ratio of the beam model is about 3, which belongs to the concrete beam with large shear span ratio. The reason why these beams are selected for analysis in this paper is that there are more experimental data and obvious shear failure modes in this shear span ratio attachment, while the failure modes of small shear span ratio beams are obviously different from the scope of consideration in this paper.
【學(xué)位授予單位】：深圳大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TU375.1

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 周朝陽;譚磊;程小念;;FRP抗剪加固鋼筋混凝土梁研究綜述[J];建筑科學(xué)與工程學(xué)報;2011年02期

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本文編號：2005425