本文選題：損傷識別 + 傳遞率函數(shù)��； 參考：《青島理工大學(xué)》2013年碩士論文

【摘要】：大型土木工程結(jié)構(gòu)長時(shí)間服役將受到各類載荷的作用以及各種不確定外在因素的影響而面臨結(jié)構(gòu)損傷的問題，一旦發(fā)生破壞將導(dǎo)致災(zāi)難性的后果。結(jié)構(gòu)損傷識別可以快速而準(zhǔn)確的判別結(jié)構(gòu)損傷與否、損傷的位置和損傷的程度，從而能夠及時(shí)地提醒人們采取有效的措施進(jìn)行補(bǔ)救，避免重大工程事故的發(fā)生。結(jié)構(gòu)損傷識別方法通常需要已知激勵(lì)信息，而激勵(lì)信息一般難以準(zhǔn)確測得，基于加速度傳遞率函數(shù)的結(jié)構(gòu)損傷識別方法不需要已知激勵(lì)信息，不需要進(jìn)行模態(tài)分析。本文利用加速度傳遞率函數(shù)對結(jié)構(gòu)進(jìn)行損傷識別研究，主要內(nèi)容如下： （1）介紹了結(jié)構(gòu)損傷識別的研究背景及意義，綜述了基于振動(dòng)的結(jié)構(gòu)損傷識別發(fā)展與研究現(xiàn)狀。 （2）介紹了傳遞率函數(shù)的概念與主成分分析的基本理論。利用加速度傳遞率函數(shù)和主成分分析進(jìn)行結(jié)構(gòu)損傷預(yù)警。首先，對加速度響應(yīng)進(jìn)行傅里葉變換構(gòu)造傳遞率函數(shù)，并形成傳遞率函數(shù)原始數(shù)據(jù)矩陣。然后，利用主成分分析法對傳遞率函數(shù)矩陣進(jìn)行降維，通過判斷結(jié)構(gòu)健康狀態(tài)和未知狀態(tài)下前兩階的主成分二維PCA空間散點(diǎn)圖來判別結(jié)構(gòu)是否發(fā)生損傷。同時(shí)，文中利用主成分置信度對結(jié)構(gòu)進(jìn)行了損傷預(yù)警。海洋平臺數(shù)值模擬和振動(dòng)臺實(shí)驗(yàn)證明了這兩種方法是有效的。 （3）利用傳遞率函數(shù)的特性定義了新的結(jié)構(gòu)定位損傷指標(biāo)，求出結(jié)構(gòu)中相鄰連點(diǎn)間的損傷指標(biāo)，通過比較相鄰兩點(diǎn)間的損傷指標(biāo)的大小來判斷海洋平臺中支撐的損傷位置。海洋平臺數(shù)值模擬和振動(dòng)臺實(shí)驗(yàn)證明了該方法是有效的。 （4）介紹了馬氏距離的概念。利用結(jié)構(gòu)在健康和損傷情況下的實(shí)測傳遞率函數(shù)數(shù)據(jù)分別建立原始數(shù)據(jù)矩陣。對原始數(shù)據(jù)矩陣進(jìn)行主成分分析，，分別求出結(jié)構(gòu)在健康和損傷情況下的主成分。計(jì)算健康狀態(tài)和損傷狀態(tài)下傳遞率函數(shù)主成分?jǐn)?shù)據(jù)間的馬氏距離，根據(jù)計(jì)算出的馬氏距離的大小對結(jié)構(gòu)的損傷程度進(jìn)行評估。海洋平臺數(shù)值模擬和振動(dòng)臺實(shí)驗(yàn)證明了該方法是可行的。
[Abstract]:Long time service for large civil engineering structures will be faced with structural damage due to the effect of various loads and the influence of various uncertain external factors. Once the damage occurs, it will result in disastrous consequences. It is timely to remind people to take effective measures to remediate and avoid major engineering accidents. The method of structural damage identification usually requires known excitation information, and the incentive information is generally difficult to accurately measure. The structural damage identification method based on the acceleration transfer rate function does not need the known incentive information and does not need modal analysis. In this paper, the acceleration transmissibility function is used to study the damage identification of structures.
(1) introduces the research background and significance of structural damage identification, and summarizes the development and research status of structural damage identification based on vibration.
(2) the concept of transfer rate function and the basic theory of principal component analysis are introduced. The structure damage warning is made by using the acceleration transfer rate function and principal component analysis. First, the Fourier transform is used to construct the transfer rate function to the acceleration response, and the original data matrix of the transfer rate function is formed. Then, the principal component analysis method is used for the transfer rate. The function matrix is reduced to determine the damage of the structure by judging the structure health state and the first two order PCA space scatter plot of the principal component in the unknown state. At the same time, the damage early-warning is made by using the principal component confidence. The two methods are proved to be effective by the numerical simulation of the offshore platform and the shaking table experiment.
(3) a new damage index of structural location is defined by the characteristics of the transfer rate function, and the damage index between adjacent links in the structure is calculated. The damage position of the support in the offshore platform is judged by comparing the damage index between two adjacent two points. The numerical simulation of the offshore platform and the shaking table experiment prove that the method is effective.
(4) the concept of Mahalanobis distance is introduced. The original data matrix is established using the measured transfer rate function data of the structure under the condition of health and damage. The principal component analysis is carried out on the original data matrix, and the principal components of the structure under the condition of health and damage are calculated respectively. The main fraction of the transfer rate function in the health state and the damage state is calculated. According to the martensitic distance, the damage degree of the structure is evaluated according to the calculated martensitic distance. The numerical simulation of the offshore platform and the shaking table experiment prove that the method is feasible.
【學(xué)位授予單位】：青島理工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2013
【分類號】：TU317

【引證文獻(xiàn)】

相關(guān)碩士學(xué)位論文 前1條

1 徐東鋒;基于振動(dòng)傳遞率函數(shù)和統(tǒng)計(jì)假設(shè)檢驗(yàn)的海洋平臺結(jié)構(gòu)損傷識別研究[D];青島理工大學(xué);2015年

本文編號：2085865