發(fā)布時(shí)間：2018-01-20 22:56

  本文關(guān)鍵詞： 預(yù)應(yīng)力混凝土梁橋 預(yù)應(yīng)力孔道 應(yīng)力波 有限元法 分?jǐn)?shù)階傅里葉變換　出處：《湘潭大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：預(yù)應(yīng)力混凝土結(jié)構(gòu)有著剛度大、抗疲勞效果好、重量輕以及能有效控制結(jié)構(gòu)撓度的優(yōu)點(diǎn)而被廣泛的應(yīng)用于現(xiàn)代橋梁工程中。預(yù)應(yīng)力管道注漿質(zhì)量直接影響混凝土梁橋結(jié)構(gòu)耐久性和承載能力,因此對(duì)預(yù)應(yīng)力管道注漿質(zhì)量進(jìn)行檢測(cè)是預(yù)防和消除結(jié)構(gòu)安全隱患的重要步驟。應(yīng)力波方法是預(yù)應(yīng)力結(jié)構(gòu)主要的無(wú)損檢測(cè)方法,研究應(yīng)力波在預(yù)應(yīng)力管道結(jié)構(gòu)中的傳播特性、影響因素和應(yīng)力波信號(hào)處理方法有助于優(yōu)化檢測(cè)方案和修正檢測(cè)結(jié)果。本文研究了橋梁預(yù)應(yīng)力混凝土結(jié)構(gòu)中縱向和橫向應(yīng)力波特性,首先利用有限元方法進(jìn)行仿真模擬分析,然后進(jìn)行實(shí)驗(yàn)測(cè)試分析,主要目的是通過(guò)應(yīng)力波法識(shí)別預(yù)應(yīng)力混凝土結(jié)構(gòu)中的注漿缺陷,本文的主要研究?jī)?nèi)容及結(jié)果如下:(1)研究了預(yù)應(yīng)力管道注漿結(jié)構(gòu)縱向透射應(yīng)力波特性和混凝土強(qiáng)度對(duì)應(yīng)力波的影響。首先用ANSYS/LS-DYNA有限元軟件建立無(wú)管道結(jié)構(gòu)混凝土有限元模型和預(yù)應(yīng)力管道結(jié)構(gòu)有限元模型,然后求解并分析空漿長(zhǎng)度和脫空度對(duì)固結(jié)波速的影響,以及混凝土強(qiáng)度對(duì)應(yīng)力波首波時(shí)間和幅度的影響。結(jié)果表明,隨著空漿長(zhǎng)度從0m增加到0.2m,固結(jié)波速?gòu)?037m/s增加到4914m/s;固結(jié)波速隨著注漿脫空度的增大而增大;隨著混凝土型號(hào)的增加,應(yīng)力波首波到達(dá)時(shí)間從63.89μs減小到51.78μs;應(yīng)力波信號(hào)幅度隨混凝土強(qiáng)度的增加而減小。(2)研究預(yù)應(yīng)力管道注漿結(jié)構(gòu)檢測(cè)的橫向反射應(yīng)力波特性,并通過(guò)分?jǐn)?shù)階傅立葉變換對(duì)預(yù)應(yīng)力管道結(jié)構(gòu)注漿缺陷進(jìn)行識(shí)別分析。首先用ANSYS/LSDYNA有限元軟件建立注漿密實(shí)度分別為0%、30%、50%、70%、100%的預(yù)應(yīng)力管道結(jié)構(gòu)有限元模型,求解并分析,利用分?jǐn)?shù)階傅立葉變換處理應(yīng)力波數(shù)據(jù),計(jì)算得到信號(hào)分?jǐn)?shù)階域幅值比。結(jié)果表明,管道反射波隨著注漿密實(shí)度增加而減小,有缺陷處的分?jǐn)?shù)階傅里葉域幅值比不相等,通過(guò)激發(fā)點(diǎn)兩側(cè)信號(hào)的分?jǐn)?shù)階域幅值比能夠識(shí)別出注漿缺陷。(3)對(duì)分?jǐn)?shù)階傅立葉域幅值比識(shí)別預(yù)應(yīng)力管道結(jié)構(gòu)注漿缺陷的方法進(jìn)行了實(shí)驗(yàn)?zāi)Ｐ蜕系尿?yàn)證分析。通過(guò)建立實(shí)際模型,利用TH402型橋梁注漿密實(shí)度檢測(cè)儀進(jìn)行數(shù)據(jù)采集,實(shí)驗(yàn)?zāi)Ｐ椭凶{脫空度為80%,缺陷長(zhǎng)度分為四組,分別是5cm、10cm、15cm、20cm,對(duì)采集數(shù)據(jù)進(jìn)行分?jǐn)?shù)階傅里葉變換,計(jì)算出分?jǐn)?shù)階域幅值比,實(shí)驗(yàn)測(cè)試結(jié)果為,在注漿不密實(shí)處的激發(fā)點(diǎn)兩側(cè)信號(hào)分?jǐn)?shù)階傅里葉域幅值比不相等,這與模擬結(jié)果相吻合。
[Abstract]:Prestressed concrete structure has a large stiffness and good anti-fatigue effect. The advantages of light weight and the ability to effectively control the deflection of the structure are widely used in modern bridge engineering. The grouting quality of prestressed pipe directly affects the durability and bearing capacity of concrete beam bridge. Therefore, it is an important step to prevent and eliminate the hidden danger of structural safety by testing the grouting quality of prestressed pipeline. The stress wave method is the main nondestructive testing method of prestressed structure. The propagation characteristics of stress waves in prestressed pipeline structures are studied. The influence factors and the signal processing method of stress wave are helpful to optimize the detection scheme and revise the test results. This paper studies the longitudinal and transverse stress wave characteristics of prestressed concrete structure. First, the finite element method is used to simulate and analyze, then the experimental test is carried out. The main purpose is to identify the grouting defects in prestressed concrete structures by the stress wave method. The main contents and results of this thesis are as follows: 1). The influence of longitudinal transmission stress wave characteristics of prestressed pipeline grouting structure and concrete strength corresponding force wave is studied. Firstly, the finite element model of concrete without pipeline structure is established by using ANSYS/LS-DYNA finite element software. And the finite element model of prestressing pipe structure. Then, the effects of slurry length and degree of void removal on the consolidation velocity, and the effect of concrete strength on the time and amplitude of the first wave of the force wave are solved and analyzed. The results show that with the increase of the length of the slurry from 0 m to 0.2 m. The consolidation velocity increased from 4037m / s to 4914m / s; The consolidation velocity increases with the increase of grouting void degree. With the increase of concrete type, the arrival time of the first wave of the stress wave decreases from 63.89 渭 s to 51.78 渭 s. The amplitude of stress wave signal decreases with the increase of concrete strength. And through fractional Fourier transform to identify the grouting defects of prestressed pipeline structure. Firstly, the grouting density is 0 ~ 30% by using ANSYS/LSDYNA finite element software. The finite element model of 100% prestressing pipe structure is solved and analyzed. The stress wave data are processed by fractional Fourier transform and the amplitude-to-value ratio of signal fractional order domain is calculated. The results show that. The reflected wave of pipeline decreases with the increase of grouting compactness, and the fractional Fourier domain amplitude ratio is not equal. The grouting defect can be identified by the fractional order amplitude ratio of the signals on both sides of the excitation point.). The method of identifying grouting defects in prestressed pipeline structure by fractional Fourier domain amplitude ratio is verified and analyzed on the experimental model. The actual model is established. The TH402 bridge grouting compactness detector was used to collect data. In the experimental model, the grouting void degree was 80 and the defect length was divided into four groups, which were 5cm / 10cm / 15cm respectively. At 20 cm, the fractional Fourier transform is used to calculate the amplitude-to-value ratio in fractional order domain. The experimental results show that the amplitude-to-value ratio of the two sides of the signal at the firing point is not equal. This agrees with the simulation results.
【學(xué)位授予單位】：湘潭大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：U441;U446

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 逄勃;范廣偉;;分?jǐn)?shù)階傅里葉變換在雷達(dá)多目標(biāo)檢測(cè)和參數(shù)估計(jì)中的應(yīng)用[J];雷達(dá)與對(duì)抗;2010年01期

相關(guān)碩士學(xué)位論文 前1條

1 雷剛;應(yīng)力波在橋梁預(yù)應(yīng)力結(jié)構(gòu)中的傳播特性及其應(yīng)用[D];湘潭大學(xué);2013年

，

本文編號(hào)：1449676