基于Hilbert-Huang理論斜拉索損傷識(shí)別方法研究
發(fā)布時(shí)間：2018-11-12 17:23
【摘要】：由于斜拉橋所具有的優(yōu)勢(shì),在現(xiàn)代橋梁的建設(shè)中很受工程師和人們的青睞,已成為大跨度橋梁的主要橋型。本文充分利用前人在信號(hào)分析領(lǐng)域研究的成果和實(shí)際服役的斜拉橋,提出了解決Hilbert-Huang變換中的難點(diǎn)問(wèn)題,并與小波分析進(jìn)行對(duì)比,通過(guò)建立有限元模型,系統(tǒng)的研究了基于Hilbert-Huang變換的斜拉橋拉索損傷識(shí)別問(wèn)題。本文主要研究?jī)?nèi)容包括:首先,通過(guò)分析Hilbert-Huang變換理論,給出了EMD結(jié)束準(zhǔn)則,并分析了其理論中不成熟部分,通過(guò)與小波分析方法對(duì)比,給出了其在損傷識(shí)別中的優(yōu)點(diǎn),并引用算例證明了HHT變換較小波分析方法簡(jiǎn)便、有效。其次,基于原始的能量變化曲線來(lái)判別噪聲與信號(hào)的分界點(diǎn)缺乏穩(wěn)定性缺點(diǎn),并根據(jù)信號(hào)與噪聲的不同的統(tǒng)計(jì)特性,提出了新的EMD去噪方法-基于自相關(guān)的函數(shù)特性EMD去噪方法,通過(guò)實(shí)驗(yàn)用該去噪方法與傅里葉變換濾波去噪方法及小波變換去噪方法進(jìn)行比較分析,驗(yàn)證了所提方法的有效性。再次,對(duì)端點(diǎn)效應(yīng)的機(jī)制以及現(xiàn)有處理方法進(jìn)行總結(jié),在其基礎(chǔ)上提出了一種自適應(yīng)的端點(diǎn)相位正弦延拓方法(只對(duì)EMD進(jìn)行端點(diǎn)效應(yīng)處理),仿真分析表明,該方法不僅比目前現(xiàn)有的延拓方法,篩選次數(shù)更少,提高信號(hào)的EMD分解精度,而且有較好的解決信號(hào)端點(diǎn)效應(yīng)的作用,有效減小Hilbert譜的端點(diǎn)效應(yīng)。最后,將改進(jìn)的Hilbert-Huang變換方法結(jié)合有限元分析模型,對(duì)在役斜拉橋拉索進(jìn)行損傷識(shí)別分析討論,通過(guò)實(shí)驗(yàn)分析,各損傷工況下均能有效的識(shí)別出拉索的損傷位置與程度。綜上,本文基于Hilbert-Huang變換的信號(hào)分析處理方法,在對(duì)給出EMD結(jié)束準(zhǔn)則,運(yùn)用提出的基于自相關(guān)的函數(shù)特性EMD去噪方法和自適應(yīng)的端點(diǎn)相位正弦延拓方法,結(jié)合有限元模型,實(shí)現(xiàn)了對(duì)某一在役斜拉橋拉索的準(zhǔn)確損傷定位與程度識(shí)別。
[Abstract]:Because of the advantages of cable-stayed bridges, they are favored by engineers and people in the construction of modern bridges, and have become the main bridge type of long-span bridges. This paper makes full use of the achievements of previous researches in the field of signal analysis and the actual cable-stayed bridge in service, and puts forward a solution to the difficult problem in Hilbert-Huang transform, and compares it with wavelet analysis, and establishes the finite element model. The problem of cable damage identification of cable-stayed bridge based on Hilbert-Huang transform is studied systematically. The main research contents of this paper are as follows: firstly, by analyzing the Hilbert-Huang transform theory, the end criterion of EMD is given, and the immature part of the theory is analyzed. Compared with the wavelet analysis method, the advantages of EMD in damage identification are given. An example is given to prove that the HHT transform is simpler and more effective than the wavelet analysis method. Secondly, judging the boundary point of noise and signal based on the original energy change curve is lack of stability, and according to the different statistical characteristics of signal and noise, In this paper, a new EMD denoising method, EMD denoising method based on autocorrelation function characteristic, is proposed. The proposed method is compared with Fourier transform filtering method and wavelet transform method to verify the effectiveness of the proposed method. Thirdly, the mechanism of endpoint effect and the existing processing methods are summarized, and an adaptive end-point phase sinusoidal continuation method (only the endpoint effect is processed for EMD) is proposed. The simulation results show that, This method not only has fewer screening times than the existing continuation methods, and improves the EMD decomposition accuracy of signals, but also has a better effect on solving the endpoint effects of signals and effectively reducing the endpoint effects of Hilbert spectra. Finally, the improved Hilbert-Huang transform method is combined with the finite element analysis model to analyze and discuss the damage identification of the cable in service cable-stayed bridge. Through the experimental analysis, the location and extent of the cable damage can be effectively identified under each damage condition. In summary, based on the signal analysis and processing method of Hilbert-Huang transform, the EMD end criterion is given, and the proposed EMD denoising method based on autocorrelation and the adaptive end-point phase sinusoidal continuation method are used to combine the finite element model. The accurate damage location and degree identification of a cable in service cable-stayed bridge are realized.
【學(xué)位授予單位】：東華理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：U446
本文編號(hào)：2327725
[Abstract]:Because of the advantages of cable-stayed bridges, they are favored by engineers and people in the construction of modern bridges, and have become the main bridge type of long-span bridges. This paper makes full use of the achievements of previous researches in the field of signal analysis and the actual cable-stayed bridge in service, and puts forward a solution to the difficult problem in Hilbert-Huang transform, and compares it with wavelet analysis, and establishes the finite element model. The problem of cable damage identification of cable-stayed bridge based on Hilbert-Huang transform is studied systematically. The main research contents of this paper are as follows: firstly, by analyzing the Hilbert-Huang transform theory, the end criterion of EMD is given, and the immature part of the theory is analyzed. Compared with the wavelet analysis method, the advantages of EMD in damage identification are given. An example is given to prove that the HHT transform is simpler and more effective than the wavelet analysis method. Secondly, judging the boundary point of noise and signal based on the original energy change curve is lack of stability, and according to the different statistical characteristics of signal and noise, In this paper, a new EMD denoising method, EMD denoising method based on autocorrelation function characteristic, is proposed. The proposed method is compared with Fourier transform filtering method and wavelet transform method to verify the effectiveness of the proposed method. Thirdly, the mechanism of endpoint effect and the existing processing methods are summarized, and an adaptive end-point phase sinusoidal continuation method (only the endpoint effect is processed for EMD) is proposed. The simulation results show that, This method not only has fewer screening times than the existing continuation methods, and improves the EMD decomposition accuracy of signals, but also has a better effect on solving the endpoint effects of signals and effectively reducing the endpoint effects of Hilbert spectra. Finally, the improved Hilbert-Huang transform method is combined with the finite element analysis model to analyze and discuss the damage identification of the cable in service cable-stayed bridge. Through the experimental analysis, the location and extent of the cable damage can be effectively identified under each damage condition. In summary, based on the signal analysis and processing method of Hilbert-Huang transform, the EMD end criterion is given, and the proposed EMD denoising method based on autocorrelation and the adaptive end-point phase sinusoidal continuation method are used to combine the finite element model. The accurate damage location and degree identification of a cable in service cable-stayed bridge are realized.
【學(xué)位授予單位】：東華理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：U446
【參考文獻(xiàn)】
相關(guān)期刊論文 前1條
1 李忠獻(xiàn),楊曉明,丁陽(yáng);應(yīng)用人工神經(jīng)網(wǎng)絡(luò)技術(shù)的大型斜拉橋子結(jié)構(gòu)損傷識(shí)別研究[J];地震工程與工程振動(dòng);2003年03期
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