本文選題：鋼筋混凝土梁 + 曲率模態(tài)��； 參考：《昆明理工大學》2014年碩士論文

【摘要】：橋梁是非常重要的基礎設施,它對地方經(jīng)濟發(fā)展有重要的作用,為人們的日常出行提供便利。近年來大型橋梁垮塌不斷出現(xiàn),此類事故一旦發(fā)生不但會帶來巨大的經(jīng)濟損失,而且威脅到人民群眾的生命安全,在這種背景下橋梁損傷檢測自然成為國內(nèi)外學者研究的熱點。 時至今日,橋梁損傷識別經(jīng)過幾十年的發(fā)展,并且獲得很大進展,如傳感器的靈敏度有所增加、和損傷相關的參數(shù)不斷被發(fā)現(xiàn),所以可供選擇的方法也日益增加,但是依然存在很多問題,本文在此基礎上對鋼筋混泥土梁的損傷識別方法進行了研究。文中將曲率模態(tài)作為損傷識別參數(shù),將它和灰色系統(tǒng)理論聯(lián)系在一起。論述了利用曲率模態(tài)關聯(lián)系數(shù)識別損傷的理論基礎。并提出一種改進的關聯(lián)系數(shù)計算方法,這種方法避免了分辨系數(shù)對結(jié)果的影響。論文用ANSYS軟件對鋼筋混凝土梁進行了三維模擬。從中提取位移模態(tài)并求得曲率模態(tài),以計算曲率模態(tài)關聯(lián)系數(shù)的方式識別其損傷,通過對比不同情況下的關聯(lián)系數(shù)曲線,得到了以下結(jié)論：結(jié)構(gòu)損傷越大關聯(lián)度突變越明顯；可以由此判斷損傷程度。距離損傷點近的節(jié)點關聯(lián)系數(shù)也會降低；距離損傷點越遠的地方關聯(lián)度越接近1,可以由此判斷損傷位置。 接下來進行模態(tài)分析試驗。實驗對象是四根2m長的鋼筋混凝土梁,其中一根是完好梁,其他三根依次是跨中損傷5%、跨中損傷10%、四分之一跨損傷5%。實驗手段如下：通過激勵實驗梁,測得其速度-時間曲線,對它進行FFT變換得到頻率-振幅曲線。最后由峰值檢測和差分運算計算出結(jié)構(gòu)的曲率模態(tài)。然后詳細說明了計算曲率模態(tài)關聯(lián)系數(shù)的步驟,并通過結(jié)果對比進一步證明了上一章提出的結(jié)論。
[Abstract]:Bridge is a very important infrastructure, it plays an important role in the development of local economy and provides convenience for people's daily travel. In recent years, large bridge collapses continue to appear. Once such accidents occur, they will not only bring huge economic losses, but also threaten the lives of the people. Under this background, bridge damage detection has naturally become a hot spot of domestic and foreign scholars. Nowadays, bridge damage identification has been developed for decades, and great progress has been made, such as the sensitivity of sensors has increased, and the parameters related to damage have been found constantly, so the available methods are increasing day by day. However, there are still many problems. On this basis, the damage identification method of reinforced concrete beams is studied in this paper. In this paper, curvature mode is regarded as the damage identification parameter, which is connected with the grey system theory. In this paper, the theoretical basis of identifying damage by using curvature modal correlation coefficient is discussed. An improved method for calculating the correlation coefficient is proposed, which avoids the influence of the resolution coefficient on the result. In this paper, three-dimensional simulation of reinforced concrete beam is carried out with ANSYS software. The displacement mode is extracted and the curvature mode is obtained, and the damage is identified by calculating the curvature modal correlation coefficient. By comparing the correlation coefficient curves under different conditions, the following conclusions are obtained: the bigger the structural damage is, the more obvious the sudden change of the correlation degree is; The degree of injury can be judged accordingly. The correlation coefficient of the node near the damage point will also be reduced, and the closer the distance from the damage point is, the closer the correlation degree will be, which can be used to judge the location of the damage. Then the modal analysis test is carried out. The experimental objects are four reinforced concrete beams with 2m length, one of which is a intact beam, the other three are in turn 5 in the middle span, 10 in the middle of the span, 5 in the 1/4 in the span. The experimental methods are as follows: by exciting the experimental beam, the velocity-time curve is measured, and the frequency-amplitude curve is obtained by FFT transformation. Finally, the curvature mode of the structure is calculated by peak detection and differential operation. Then, the steps of calculating the curvature modal correlation coefficient are explained in detail, and the conclusion in the previous chapter is further proved by comparing the results.
【學位授予單位】：昆明理工大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：U446;U448.34

【參考文獻】

相關期刊論文 前1條

1 劉義倫;時圣鵬;廖偉;;利用曲率模態(tài)識別橋梁損傷的研究[J];振動與沖擊;2011年08期

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本文編號：1843104