發(fā)布時(shí)間：2018-04-26 21:32

  本文選題：橋梁結(jié)構(gòu) + 損傷識(shí)別��； 參考：《吉林大學(xué)》2014年碩士論文

【摘要】：隨著現(xiàn)代經(jīng)濟(jì)的高速發(fā)展，橋梁所承受的交通荷載日益增加，外部惡劣環(huán)境導(dǎo)致材料不斷老化，橋梁結(jié)構(gòu)容易出現(xiàn)累積損傷，進(jìn)而導(dǎo)致承載能力不足。綜合考慮安全和經(jīng)濟(jì)因素，十分有必要開(kāi)展對(duì)現(xiàn)役橋梁結(jié)構(gòu)的損傷識(shí)別和健康監(jiān)測(cè)，，了解橋梁的健康狀況，保障結(jié)構(gòu)的安全運(yùn)營(yíng)，減少垮塌事故的發(fā)生。 基于動(dòng)力響應(yīng)的損傷識(shí)別技術(shù)因?yàn)槠洳挥绊懡Y(jié)構(gòu)正常工作，可實(shí)現(xiàn)長(zhǎng)期或在線監(jiān)測(cè)，操作簡(jiǎn)單方便等特點(diǎn)，而得到了廣泛的關(guān)注和研究。但大多是借助模態(tài)分析理論，得到系統(tǒng)的模態(tài)參數(shù)，然后進(jìn)行損傷識(shí)別。模態(tài)分析的方法具有良好的理論基礎(chǔ)，并且在相關(guān)的研究中取得了不錯(cuò)的損傷識(shí)別效果，但仍需解決諸如功率泄露等一系列的問(wèn)題。本文結(jié)合時(shí)間序列分析等統(tǒng)計(jì)學(xué)的辦法，直接利用結(jié)構(gòu)時(shí)域響應(yīng)（加速度信號(hào)）的統(tǒng)計(jì)特征進(jìn)行損傷識(shí)別。相比于模態(tài)分析，此類方法更加便捷，同時(shí)避免了有效信息的丟失。本文開(kāi)展的研究工作如下： 1.時(shí)間序列模型的自回歸系數(shù)描述的是結(jié)構(gòu)某時(shí)刻的響應(yīng)受之前時(shí)刻響應(yīng)的影響程度，反映的是結(jié)構(gòu)的固有特性。進(jìn)一步的，我們可建立起自回歸系數(shù)與結(jié)構(gòu)物理特征量的關(guān)系式。因此，結(jié)構(gòu)的損傷可以通過(guò)自回歸系數(shù)改變體現(xiàn)出來(lái)�；跁r(shí)間序列模型的自回歸系數(shù)，本文建立了加權(quán)距離指標(biāo)（），數(shù)值算例表明該指標(biāo)可以識(shí)別損傷的出現(xiàn)，但當(dāng)損傷程度較小時(shí)識(shí)別效果不夠理想，并且無(wú)法損傷定位。 2.隨機(jī)信號(hào)的自相關(guān)系數(shù)反映的是信號(hào)前后時(shí)刻之間的相關(guān)程度，它對(duì)系統(tǒng)的描述性跟時(shí)間序列模型的自回歸系數(shù)是類似的。本文利用響應(yīng)信號(hào)的一階自相關(guān)系數(shù)（）進(jìn)行了損傷識(shí)別，相比于基于自回歸系數(shù)的加權(quán)距離，該指標(biāo)對(duì)小損傷的識(shí)別更加敏感，但無(wú)法進(jìn)行損傷定位。 3.我們將結(jié)構(gòu)上某點(diǎn)在一段時(shí)間內(nèi)測(cè)得的信號(hào)值的平方和記作，損傷位置的 在損傷前后的變化程度（）要大于其他位置�；诖嗽�，我們對(duì)前文的數(shù)值算例進(jìn)行損傷定位，結(jié)果表明，該指標(biāo)對(duì)損傷位置具有良好的識(shí)別效果，并且能夠定性反映損傷程度，但是該指標(biāo)不能用來(lái)在線監(jiān)測(cè)損傷的產(chǎn)生。 考慮到以上三種指標(biāo)損傷的識(shí)別效果，本文采用兩步法進(jìn)行損傷識(shí)別：先利用 或者識(shí)別損傷的出現(xiàn)，在此基礎(chǔ)上利用C指標(biāo)進(jìn)行損傷定位。
[Abstract]:With the rapid development of modern economy, the traffic load on the bridge is increasing day by day, and the external environment leads to the aging of materials, and the bridge structure is prone to cumulative damage, which leads to the insufficient bearing capacity. Considering the safety and economic factors, it is necessary to carry out damage identification and health monitoring of existing bridge structures, to understand the health status of bridges, to ensure the safe operation of the structures and to reduce the occurrence of collapsing accidents. The damage identification technology based on dynamic response has been widely studied because it can realize long-term or on-line monitoring and easy operation because it does not affect the normal work of the structure. However, the modal parameters of the system are obtained by modal analysis theory, and then damage identification is carried out. The modal analysis method has a good theoretical foundation, and has achieved good damage identification effect in related research, but a series of problems such as power leakage still need to be solved. Combined with time series analysis and other statistical methods, this paper directly utilizes the statistical characteristics of the time-domain response (acceleration signal) of the structure to identify the damage. Compared with modal analysis, this method is more convenient and avoids the loss of effective information. The research work carried out in this paper is as follows: 1. The autoregressive coefficients of the time series model describe the degree to which the response of the structure at a certain time is affected by the response of the previous moment, and reflect the inherent characteristics of the structure. Furthermore, we can establish the relation between the autoregressive coefficient and the structural physical characteristic quantity. Therefore, the damage of the structure can be reflected by the change of autoregressive coefficient. Based on the autoregressive coefficient of time series model, a weighted distance index is established in this paper. The numerical example shows that the index can identify the occurrence of damage, but when the degree of damage is small, the identification effect is not satisfactory, and the damage location can not be achieved. 2. The autocorrelation coefficient of the random signal reflects the correlation between the time before and after the signal, and its descriptive property of the system is similar to that of the autoregressive coefficient of the time series model. In this paper, the first order autocorrelation coefficient of the response signal is used to identify the damage. Compared with the weighted distance based on the autoregressive coefficient, the index is more sensitive to the identification of small damage, but it can not locate the damage. 3. We take the square sum of the signal values measured internally at a point in the structure over a period of time as the damage location. The degree of change before and after injury was greater than that in other locations. Based on this principle, the damage location of the numerical examples in the previous paper is carried out. The results show that the index has a good effect on identifying the damage location, and it can reflect the damage degree qualitatively. But this indicator cannot be used to monitor damage online. Considering the damage recognition effect of the above three indexes, this paper adopts the two-step method to identify the damage. Or identify the appearance of damage, on the basis of C index damage location.
【學(xué)位授予單位】：吉林大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：U446;U441

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 顧培英,陳厚群,李同春,鄧昌;用應(yīng)變模態(tài)技術(shù)診斷梁結(jié)構(gòu)的損傷[J];地震工程與工程振動(dòng);2005年04期

2 史治宇,張令彌,呂令毅;基于模態(tài)應(yīng)變能診斷結(jié)構(gòu)破損的修正方法[J];東南大學(xué)學(xué)報(bào)(自然科學(xué)版);2000年03期

3 郭健;顧正維;孫炳楠;陳勇;;基于小波分析的橋梁健康監(jiān)測(cè)方法[J];工程力學(xué);2006年12期

4 李忠獻(xiàn);楊曉明;丁陽(yáng);;基于結(jié)構(gòu)響應(yīng)統(tǒng)計(jì)特征的神經(jīng)網(wǎng)絡(luò)損傷識(shí)別方法[J];工程力學(xué);2007年09期

5 薛祥;霍達(dá);滕海文;姜雪峰;;離散空間小波分析的環(huán)境荷載下橋梁的損傷識(shí)別[J];公路交通科技;2006年07期

6 張啟偉,袁萬(wàn)s

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