本文選題：CFRP　切入點(diǎn)：螺旋箍筋　出處：《湖南大學(xué)》2015年碩士論文

【摘要】：對混凝土施加約束可以有效改善混凝土的材料性能。相比素混凝土,約束混凝土在抗壓強(qiáng)度和變形能力上有顯著提高,從而使構(gòu)件具有更好的性能和抗震能力。通常對混凝土施加約束的方法有FRP約束、鋼管約束、箍筋約束等,不同的約束方式會(huì)導(dǎo)致構(gòu)件不同的受力特點(diǎn)。因此對比不同約束形式的受力性能,探索更加有效的約束方式具有較大的工程意義。本文首先討論了FRP約束混凝土構(gòu)件和螺旋箍筋約束混凝土構(gòu)件的性能特點(diǎn),在此基礎(chǔ)上提出了FRP-螺旋箍筋復(fù)合約束混凝土構(gòu)件,此種約束能發(fā)揮FRP和螺旋箍筋材料的特點(diǎn)。本文主要工作如下:(1)本文設(shè)計(jì)了30組共240個(gè)FRP試件,進(jìn)行動(dòng)態(tài)拉伸試驗(yàn)。得到了試件的應(yīng)力-應(yīng)變曲線,并用高速相機(jī)記錄了試件破壞全過程。分析了溫度和應(yīng)變率對其強(qiáng)度和韌性的影響,對比了各種條件下的破壞形態(tài),并通過Weibull分析總結(jié)其力學(xué)性能變化規(guī)律。(2)在FRP材性試驗(yàn)的基礎(chǔ)上,選用CFRP進(jìn)行后續(xù)復(fù)合約束混凝土抗沖擊性能試驗(yàn)研究。設(shè)計(jì)了8組共24個(gè)約束試件,包括2組CFRP單獨(dú)約束,2組螺旋箍筋單獨(dú)約束和4組CFRP-螺旋箍筋復(fù)合約束試件。記錄了試件沖擊力時(shí)程曲線,應(yīng)變時(shí)程曲線,并用高速相機(jī)進(jìn)行了拍攝。(3)總結(jié)了各組試件的沖擊力時(shí)程曲線和應(yīng)變時(shí)程曲線的特點(diǎn),對比了各組試件的破壞形態(tài),探討CFRP層數(shù)、螺旋箍筋間距、沖擊能量和錘重等參數(shù)對試件抗沖擊性能的影響。(4)采用ANSYS/LS-DYNA軟件對試驗(yàn)過程進(jìn)行模擬,模擬結(jié)果和試驗(yàn)較為吻合,在此基礎(chǔ)上,對沖擊過程中能量的變化規(guī)律進(jìn)行了探討。本文研究結(jié)果表明,FRP具有應(yīng)變率效應(yīng),拉伸強(qiáng)度和韌性隨著應(yīng)變率的提高而提高;拉伸強(qiáng)度對溫度不敏感,只有到達(dá)100℃才有明顯降低;與常溫相比,溫度的改變會(huì)造成韌性的下降。CFRP-螺旋箍筋復(fù)合約束混凝土試件能有效發(fā)揮兩種材料的優(yōu)勢,使試件具有更高的抗壓強(qiáng)度和更好的耗能能力。約束形式的改變對試件力學(xué)性能影響較大,沖擊能量和錘頭重量對抗沖擊承載力影響不顯著。
[Abstract]:The material properties of concrete can be effectively improved by imposing restraint on concrete. Compared with plain concrete, confined concrete has a significant increase in compressive strength and deformation ability. In order to make the members have better performance and anti-seismic ability. Usually the methods of imposing constraints on concrete include FRP constraint, steel pipe constraint, stirrups constraint, etc. Different constraints will lead to different mechanical characteristics of the member. It is of great engineering significance to explore more effective restraint modes. In this paper, the performance characteristics of FRP confined concrete members and spiral stirrups confined concrete members are discussed, and on this basis, the FRP-spiral stirrups composite confined concrete members are proposed. This constraint can take advantage of the characteristics of FRP and spiral stirrups. The main work of this paper is as follows: (1) in this paper, 30 groups of 240 FRP specimens are designed for dynamic tensile tests. The stress-strain curves of the specimens are obtained. The whole failure process of the specimen was recorded with a high-speed camera. The effects of temperature and strain rate on the strength and toughness of the specimen were analyzed, and the failure patterns under various conditions were compared. On the basis of FRP properties test, CFRP was selected to study the impact resistance of concrete with compound confinement. Eight groups of 24 confined concrete specimens were designed. It consists of two groups of CFRP alone and two groups of spiral stirrups and four groups of CFRP-helical stirrups composite confined specimens. The time history curve of impact force and strain time history curve of the specimen are recorded. The characteristics of impact time history curve and strain history curve of each group of specimens are summarized, the failure patterns of each group are compared, the number of CFRP layers and the space of spiral stirrups are discussed. The effect of parameters such as impact energy and hammer weight on the impact resistance of the specimen is simulated by ANSYS/LS-DYNA software. The simulation results are in good agreement with the test results. The change of energy during impact is discussed. The results show that FRP has strain rate effect, tensile strength and toughness increase with the increase of strain rate, tensile strength is not sensitive to temperature, When the temperature reaches 100 鈩，

本文編號：1685498