發(fā)布時(shí)間：2018-03-07 07:14

  本文選題：FRP筋　切入點(diǎn)：ECC　出處：《東南大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：纖維增強(qiáng)水泥基復(fù)合材料(Engineered Cementitious Composites簡稱ECC)是一種新型高性能土木工程建筑材料,具有假應(yīng)變硬化和超高的韌性等特性,在體積摻量為2%的情況下,其極限拉應(yīng)變約為混凝土的300倍,而極限狀態(tài)下最大裂縫寬度僅為100μm左右,將其用于工程結(jié)構(gòu)可大幅提升結(jié)構(gòu)的承載力、延性和耗能性能。然而,FRP筋與ECC的粘結(jié)性能是保證兩者協(xié)同工作的關(guān)鍵,是研究FRP筋增強(qiáng)ECC結(jié)構(gòu)的重要課題之一。因此,本文對FRP筋與ECC的粘結(jié)性能進(jìn)行了試驗(yàn)、理論以及數(shù)值模擬三個(gè)方面的研究：(1)根據(jù)FRP筋與ECC拉拔試驗(yàn)結(jié)果,分析了FRP筋與ECC的粘結(jié)滑移機(jī)理,和錨固長度、FRP筋的類型、FRP筋直徑以及FRP筋表面形狀等因素對FRP筋與ECC粘結(jié)性能的影響。結(jié)果表明：光圓和螺紋FRP筋與ECC的粘結(jié)滑移曲線分為上升段、下降段以及殘余段,在殘余段,粘結(jié)強(qiáng)度會有波動,且螺紋FRP筋與ECC的粘結(jié)滑移曲線波動幅度比光圓FRP筋的明顯。CFRP筋與ECC的粘結(jié)滑移曲線上升段的斜率大于GFRP筋的,且峰值粘結(jié)應(yīng)力對應(yīng)的位移小于GFRP筋對應(yīng)的位移,這主要是因?yàn)镃FRP筋的彈性模量大于GFRP筋的彈性模量所引起的：在錨固長度一定的情況下,隨著直徑的增加,極限平均粘結(jié)應(yīng)力減小,在直徑一定的情況下,隨著錨固長度的增加,極限荷載增加,而極限平均粘結(jié)應(yīng)力減�。宦菁yGFRP筋與ECC的粘結(jié)強(qiáng)度明顯高于光圓GFRP筋與ECC的粘結(jié)強(qiáng)度,說明對FRP筋表面進(jìn)行處理可以很大程度上提高FRP筋與ECC之間的粘結(jié)性能。(2)根據(jù)FRP筋表面貼應(yīng)變片的拉拔試驗(yàn),測得FRP筋在拉拔過程中應(yīng)變的變化,計(jì)算得到試件在錨固長度范圍內(nèi)各測點(diǎn)的粘結(jié)應(yīng)力以及FRP筋與ECC相對滑移的分布規(guī)律,從而得到不同位置處FRP筋與ECC粘結(jié)應(yīng)力與相對滑移的關(guān)系,進(jìn)而通過位置函數(shù)ψ(x)對不同位置處的粘結(jié)滑移關(guān)系進(jìn)行修正,建立了考慮錨固位置影響的FRP筋與ECC的粘結(jié)滑移本構(gòu)關(guān)系,為FRP筋增強(qiáng)ECC結(jié)構(gòu)和構(gòu)件的有限元分析提供基本條件。(3)結(jié)合試驗(yàn)得到的粘結(jié)滑移本構(gòu)關(guān)系中的參數(shù),提出三線型粘結(jié)滑移本構(gòu)模型,并通過理論推導(dǎo)得出FRP筋應(yīng)力、FRP筋與ECC的相對滑移、FRP筋表面的粘結(jié)應(yīng)力、加載端的拉拔力等物理量的數(shù)學(xué)表達(dá)式,理論計(jì)算得到的加載端和自由端的荷載位移曲線與試驗(yàn)結(jié)果吻合較好,驗(yàn)證了FRP筋與ECC粘結(jié)滑移本構(gòu)模型的正確性；并對粘結(jié)滑移本構(gòu)關(guān)系中的各參數(shù)、FRP筋直徑、錨固長度、FRP筋的彈性模量以及ECC的彈性模量等參數(shù)對最大拉拔力的影響進(jìn)行了分析,最后給出了FRP筋基本錨固長度的理論計(jì)算公式。(4)采用ATENA軟件對拉拔試驗(yàn)進(jìn)行數(shù)值模擬,結(jié)果表明：數(shù)值模擬得到的加載端荷載位移曲線、FRP筋應(yīng)力沿錨固方向的分布曲線以及FRP筋與ECC的粘結(jié)應(yīng)力沿錨固方向的分布曲線與理論計(jì)算結(jié)果基本吻合,表明FRP筋與ECC粘結(jié)滑移本構(gòu)模型的合理可行性,為后續(xù)ECC結(jié)構(gòu)的研究提供新的分析手段。通過對錨固長度、FRP筋直徑和最大粘結(jié)應(yīng)力三個(gè)參數(shù)的分析發(fā)現(xiàn)：其它參數(shù)相同的情況下,隨著錨固長度的增加,FRP筋與ECC的拉拔力會有很大的提高,殘余荷載也對應(yīng)增加；隨著直徑的增加,最大拉拔力和殘余荷載也增加；隨著最大粘結(jié)應(yīng)力的增加,拉拔力增加,殘余荷載保持不變。
[Abstract]:Fiber reinforced cement composite (Engineered Cementitious Composites referred to as ECC) is a new type of high performance of civil engineering materials, with pseudo strain hardening and toughness of high properties, in volume 2%, the ultimate tensile strain of concrete is about 300 times, while the maximum crack width limit state only about 100 m, which will be used in engineering structure can greatly improve the structure bearing capacity, ductility and energy dissipation performance. However, bond properties of FRP bars and ECC is the key to ensure that both the collaborative work, is one of the important topics of FRP reinforced ECC structure is enhanced. Therefore, the bond performance of FRP bar and ECC the tests were conducted on three aspects: Theory and numerical simulation (1) according to the test results of ECC FRP analysis and drawing bar, bond slip mechanism of FRP reinforced with ECC, and the anchorage length, type FRP bars, FRP bars with the diameter of And the effect of surface shape of FRP tendon and other factors on the FRP reinforcement and the bond performance of the ECC. The results show that the bond slip curve of light and thread FRP bars and ECC divided into ascending, descending and residual period, in the period of residual, the bond strength will fluctuate, and the bond slip curve slope fluctuation thread FRP bars and ECC the ratio of bond slip curve was.CFRP bars and FRP bars ECC round up section is greater than the GFRP reinforcement, displacement and the peak bond stress corresponding to the corresponding reinforcement is less than GFRP, this is mainly because the elastic modulus of CFRP bars is greater than GFRP bars caused by the anchorage length next, with the increase of the diameter limit, the average bond stress decreases in certain diameter, with the increase of the anchorage length, the ultimate load increases, and the limit of the average bond stress decreases; bond strength of reinforced ECC and GFRP were significantly higher than those of thread 鍏夊渾GFRP絳嬩笌ECC鐨勭矘緇撳己搴，

本文編號：1578437