本文關(guān)鍵詞：環(huán)境振動下工程結(jié)構(gòu)模態(tài)辨識方法改進(jìn)與軟件系統(tǒng)研發(fā)　出處：《重慶大學(xué)》2014年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 模態(tài)參數(shù)辨識 改進(jìn)的EMD分解 改進(jìn)的NExT法 軟件研發(fā)

【摘要】：工程結(jié)構(gòu)模態(tài)辨識和損傷識別作為健康監(jiān)測與安全性評估核心技術(shù)和理論基礎(chǔ)，已經(jīng)成為了土木工程領(lǐng)域關(guān)注的焦點和研究的熱點。鑒于工程結(jié)構(gòu)具有結(jié)構(gòu)尺寸大、約束條件復(fù)雜、造型復(fù)雜等特點，對工程結(jié)構(gòu)進(jìn)行人為激勵以及對激勵信號進(jìn)行有效的測量變得非常困難，從而傳統(tǒng)的基于輸入輸出信號模態(tài)參數(shù)辨識理論和方法在工程結(jié)構(gòu)中難以適用，而環(huán)境激勵下的結(jié)構(gòu)模態(tài)參數(shù)辨識方法具有其自身突出的優(yōu)點：不需要施加人為激勵、不需要測量激勵信號、測量費(fèi)用較低、測量時不影響結(jié)構(gòu)的正常工作、更加符合實際情況等，在工程界得到了廣泛的應(yīng)用。但現(xiàn)有的模態(tài)參數(shù)辨識方法在精度、魯棒性、效率以及經(jīng)濟(jì)性能指標(biāo)等方面仍然存在許多缺點，，在實際工程中的應(yīng)用尚處于發(fā)展階段，仍需進(jìn)一地步深入研究和不斷完善。 本文針對環(huán)境激勵下工程結(jié)構(gòu)模態(tài)參數(shù)辨識方法進(jìn)行了研究，并針對這些方法存在的不足進(jìn)行了改進(jìn)，進(jìn)一步研發(fā)了模態(tài)參數(shù)辨識的軟件系統(tǒng)。歸結(jié)起來主要內(nèi)容如下： ①在簡要介紹工程結(jié)構(gòu)健康監(jiān)測、安全性評估的重要意義的基礎(chǔ)上，詳細(xì)論述了環(huán)境激勵下工程結(jié)構(gòu)模態(tài)參數(shù)識別的研究背景和意義。對環(huán)境激勵下模態(tài)參數(shù)識別的主要方法進(jìn)行了闡述，最后介紹了本文的主要工作內(nèi)容。 ②針對EMD分解出現(xiàn)的端點效應(yīng)問題和模態(tài)混疊問題，通過實例分別采用了基于支持向量回歸機(jī)抑制端點效應(yīng)的EMD方法和基于Hilbert特性的EMD模態(tài)解混疊方法。實例結(jié)果表明：本文所采用的改進(jìn)方法能夠有效抑制端點效應(yīng)和消除模態(tài)混疊現(xiàn)象。進(jìn)一步運(yùn)用改進(jìn)的EMD方法對四層鋼框架試驗進(jìn)行了模態(tài)參數(shù)的辨識，證明了改進(jìn)EMD方法能夠正確識別結(jié)構(gòu)模態(tài)參數(shù)。 ③針對信號預(yù)處理方法NExT法進(jìn)行了改進(jìn)，并將改進(jìn)的NExT法和五種模態(tài)參數(shù)辨識方法（STD法、ITD法、復(fù)指數(shù)法、ARMA法和ERA法）相結(jié)合來識別結(jié)構(gòu)的模態(tài)參數(shù)。通過同濟(jì)大學(xué)十二層鋼筋混凝土模型振動臺試驗數(shù)據(jù)，作者利用改進(jìn)的NExT法和未改進(jìn)的NExT法，開展了小震作用下和大震作用下的結(jié)構(gòu)模態(tài)參數(shù)識別工作。結(jié)果表明：針對地震作用下結(jié)構(gòu)模態(tài)參數(shù)識別的實例，改進(jìn)的NExT法比未改進(jìn)的NExT法具有更高的精度。 ④利用MATLAB下的GUI平臺，研發(fā)了環(huán)境振動下結(jié)構(gòu)模態(tài)參數(shù)辨識的可視化軟件系統(tǒng)。包括文件讀取模塊，幾何數(shù)據(jù)模塊，振動數(shù)據(jù)模塊（包含數(shù)據(jù)處理，例如濾波，奇異熵去噪等），處理分析模塊（包含各種參數(shù)識別方法，例如隨機(jī)子空間法、HHT法、STD法等），結(jié)果處理模塊�；谒邪l(fā)的軟件系統(tǒng)，對數(shù)值算例鋼桁架懸索橋在環(huán)境激勵下模態(tài)參數(shù)問題進(jìn)行了辨識，結(jié)果表明：整個辨識過程既清晰明了又準(zhǔn)確方便。
[Abstract]:Modal identification and damage identification of engineering structures are the core technology and theoretical basis of health monitoring and safety assessment. It has become the focus and research focus in the field of civil engineering. In view of the large structure size, complex constraints, complex modeling and other characteristics. It is very difficult to carry out artificial excitation and effective measurement of the excitation signal of engineering structure, so the traditional modal parameter identification theory and method based on input and output signal is difficult to apply in engineering structure. The modal parameter identification method under environmental excitation has its own outstanding advantages: no artificial excitation, no need to measure the excitation signal, the measurement cost is low, the measurement does not affect the normal operation of the structure. More in line with the actual situation, has been widely used in engineering, but the existing modal parameter identification methods in the accuracy, robustness, efficiency and economic performance indicators still have many shortcomings. The application in practical engineering is still in the developing stage, which needs further research and improvement. In this paper, the identification methods of modal parameters of engineering structures under environmental excitation are studied, and the shortcomings of these methods are improved. The software system of modal parameter identification is further developed. 1 on the basis of brief introduction of the importance of engineering structure health monitoring and safety assessment. The research background and significance of modal parameter identification of engineering structures under environmental excitation are discussed in detail. The main methods of modal parameter identification under environmental excitation are described. Finally, the main work contents of this paper are introduced. 2 for the end point effect problem and modal aliasing problem of EMD decomposition. EMD method based on support vector regression machine to suppress endpoint effect and EMD mode de-aliasing method based on Hilbert characteristic are used by examples. The results show that:. The improved method in this paper can effectively suppress the end-point effect and eliminate the phenomenon of modal aliasing. Further, the improved EMD method is used to identify the modal parameters of the four-story steel frame test. It is proved that the improved EMD method can correctly identify the structural modal parameters. (3) the signal preprocessing method (NExT) is improved, and the improved NExT method and five modal parameter identification methods (NExT method and complex exponent method) are introduced. ARMA method and ERA method are combined to identify the modal parameters of the structure. The shaking table test data of 12 story reinforced concrete model of Tongji University are used. The author uses the improved NExT method and the unimproved NExT method. The identification of structural modal parameters under the action of small earthquakes and large earthquakes is carried out. The results show that the identification of structural modal parameters under earthquake action is an example. The improved NExT method has higher accuracy than the unimproved NExT method. 4 using the GUI platform under MATLAB, a visual software system for structural modal parameter identification under ambient vibration is developed, including file reading module and geometric data module. Vibration data module (including data processing, such as filtering, singular entropy denoising, etc.) processing and analysis module (including a variety of parameter identification methods, such as random subspace method / HHT / STD method). Based on the developed software system, the modal parameters of steel truss suspension bridge under ambient excitation are identified. The results show that the identification process is clear, accurate and convenient.
【學(xué)位授予單位】：重慶大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TP311.52;TU317

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