本文選題：損傷識(shí)別 + 鏡像閉合延拓�。� 參考：《長(zhǎng)沙理工大學(xué)》2014年碩士論文

【摘要】：隨著經(jīng)濟(jì)實(shí)力和科學(xué)技術(shù)的飛速發(fā)展,高層建筑在我國(guó)如雨后春筍般拔地而起。高層建筑結(jié)構(gòu)在長(zhǎng)期使用過程中的健康和安全也越來越受到人們的關(guān)注,結(jié)構(gòu)損傷識(shí)別以及結(jié)構(gòu)健康監(jiān)測(cè)已經(jīng)成為現(xiàn)在工程界熱門研究方向。本文首先對(duì)結(jié)構(gòu)損傷識(shí)別的方法以及國(guó)內(nèi)外的研究現(xiàn)狀進(jìn)行綜述,并重點(diǎn)對(duì)Hilbert—Huang變換方法(HHT)進(jìn)行了介紹。HHT方法是一種全新的、自適應(yīng)的時(shí)頻分析方法,因其在處理非線性、非穩(wěn)態(tài)信號(hào)方面的優(yōu)良特性,被廣泛運(yùn)用到眾多領(lǐng)域的研究中。由于Hilbert—Huang變換理論尚未在數(shù)學(xué)上得到嚴(yán)格意義上的證明,其算法自身也存在一定的缺陷,進(jìn)而影響到了其對(duì)模態(tài)參數(shù)的識(shí)別。本文對(duì)HHT方法中存在端點(diǎn)效應(yīng)和模態(tài)混疊問題以及對(duì)參數(shù)識(shí)別造成的影響進(jìn)行了分析,闡述了利用鏡像閉合延拓抑制端點(diǎn)效應(yīng)以及利用總體平均經(jīng)驗(yàn)?zāi)B(tài)分解抑制模態(tài)混疊的方法。通過數(shù)值算例證明了鏡像閉合延拓和總體平均經(jīng)驗(yàn)?zāi)B(tài)分解的在抑制端點(diǎn)效應(yīng)以及模態(tài)混疊問題方面的有效性。將改進(jìn)的Hilbert—Huang變換應(yīng)用到地震作用下結(jié)構(gòu)損傷的識(shí)別中。建立了一個(gè)三自由度剪切型剛度退化模型,利用改進(jìn)的Hilbert—Huang變換對(duì)該模型在不同強(qiáng)度地震作用下的響應(yīng)進(jìn)行分析,通過結(jié)構(gòu)瞬時(shí)頻率的變化對(duì)結(jié)構(gòu)是否出現(xiàn)損傷進(jìn)行識(shí)別,提出了一階固有模態(tài)函數(shù)(IMF)能量識(shí)別損傷位置的方法。將改進(jìn)的HHT方法應(yīng)用到對(duì)實(shí)際工程的健康監(jiān)控?cái)?shù)據(jù)的分析中,對(duì)某辦公樓建筑在Northridge地震中獲得的地震響應(yīng)進(jìn)行HHT分析,通過瞬時(shí)頻率以及一階IMF能量變化規(guī)律識(shí)別了該建筑在地震中發(fā)生損傷的情況,證明了改進(jìn)的Hilbert—Huang變換在實(shí)際應(yīng)用中的實(shí)用性。
[Abstract]:With the rapid development of economic strength and science and technology, high-rise buildings have sprung up like bamboo shoots after the rain in China. The health and safety of high building structures are becoming more and more popular in the process of long-term use. Structural damage identification and structural health monitoring have become a hot research direction in the engineering field. The method of structural damage identification and the current research status at home and abroad are reviewed, and the Hilbert Huang transform method (HHT) is introduced. The.HHT method is a new and adaptive time-frequency analysis method, which is widely used in the research of many fields because of its excellent characteristics in dealing with nonlinear and unsteady signals. The Hilbert Huang transformation theory has not been proved in the strict sense of mathematics, and its algorithm itself has some defects, and then it affects its identification of modal parameters. This paper analyzes the existence of endpoint effect and modal aliasing and the influence on parameter identification in the HHT method, and expounds the use of the mirror image. The closed extension suppresses the endpoint effect and uses the overall mean empirical mode decomposition to suppress the modal aliasing. Through numerical examples, the effectiveness of the mirror closed extension and the overall mean empirical mode decomposition in the suppression of endpoint and modal aliasing problems is proved. The improved Hilbert Huang transformation is applied to the earthquake action. In the identification of lower structural damage, a three degree of freedom shear type stiffness degradation model is established, and the modified Hilbert - Huang transformation is used to analyze the response of the model under different intensity earthquakes. The first order inherent modal function (IMF) can be identified by the change of the instantaneous frequency of the structure to identify the damage of the structure. The modified HHT method is applied to the analysis of the health monitoring data of the actual project. The seismic response of an office building in the Northridge earthquake is analyzed by HHT. The damage of the building in the earthquake is identified by the instantaneous frequency and the law of the first order IMF energy change. The practicability of the improved Hilbert - Huang transform in practical application is given.

【學(xué)位授予單位】：長(zhǎng)沙理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：TU317

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 高贊明,孫宗光,倪一清;基于振動(dòng)方法的汲水門大橋損傷檢測(cè)研究[J];地震工程與工程振動(dòng);2001年S1期

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本文編號(hào)：1829292