本文關(guān)鍵詞：基于小波包分析的含水巖石破裂前兆研究　出處：《東北大學(xué)》2014年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 聲發(fā)射 含水飽和度 小波包分析 信號奇異性 破裂前兆

【摘要】：材料在應(yīng)力作用下的變形與裂紋擴展是結(jié)構(gòu)失效的重要機制,當(dāng)材料局部區(qū)域產(chǎn)生應(yīng)力集中現(xiàn)象時,能量會被瞬間快速釋放。因此,從能量的角度來研究含水巖石失穩(wěn)破壞的性質(zhì)是切實可行的。然而,當(dāng)這種能量以聲發(fā)射信號的方式被接收到的過程中,由于其非平穩(wěn)性,使得利用傳統(tǒng)的信號分析技術(shù)難以對獲得的聲發(fā)射信號進(jìn)行全面、系統(tǒng)、有效的解讀。因此,通過何種方法能更為行之有效的解讀與含水巖石破壞過程如影相隨的能量變化便成了各國專家與學(xué)者爭相研究的熱點問題。論文首先在實驗室內(nèi)通過對不同飽和度的巖石進(jìn)行單軸壓縮試驗,獲取其破壞過程中的聲發(fā)射數(shù)據(jù),然后,研究了隨著飽和度的變化,砂巖聲發(fā)射事件數(shù)的變化規(guī)律。其次,利用小波包變換對聲發(fā)射信號進(jìn)行處理,在比較了利用小波分析和小波包分析兩種降噪方法的優(yōu)劣性的同時較為有效的對信號進(jìn)行了降噪。通過對小波包能量頻帶的分析,研究了含水巖石聲發(fā)射信號的能量頻帶分布特點,比較了在破裂前后能量頻帶的變化規(guī)律,尋找到了含水巖石破壞過程中的主頻帶。再次,根據(jù)能量原理,依據(jù)時間序列,利用信號奇異性,通過小波包分解與重構(gòu),計算Lipschitza值,將最小α值對應(yīng)的時間序列中的時間點作為含水巖石破裂的時間,較為有效地提取到了含水巖石破裂的時間信息。最后,根據(jù)一個矩陣可由它的所有特征向量完全表示,而每一個向量所對應(yīng)的特征值,就代表了矩陣在這一向量上的貢獻(xiàn)率的理論,基于當(dāng)信號發(fā)生變化時,信號的各頻率成分間會產(chǎn)生不同的抑制或增強作用,與非破裂的信號相比,破裂前一小段時間內(nèi)的信號上的某些頻帶的能量會激增,某些頻帶上的能量會驟減的思想,將聲發(fā)射信號進(jìn)行小波包分解并重構(gòu)得到小波包結(jié)點系數(shù),以小波包結(jié)點系數(shù)為特征向量,求得小波包結(jié)點系數(shù)特征值,通過特征值的突變來預(yù)測含水巖石的破裂。雖然實驗室內(nèi)的巖樣與工程中的巖體的聲發(fā)射信號的能量間有所差別,但是萬變不離其宗,本文對含水巖石的損傷過程和發(fā)展趨勢及破裂預(yù)測具有現(xiàn)實的指導(dǎo)意義。
[Abstract]:The deformation and crack propagation of materials under stress is an important mechanism of structural failure. When the stress concentration occurs in the local region of materials, the energy will be released instantly and quickly. It is feasible to study the instability and failure of water-bearing rock from the angle of energy. However, when this energy is received as acoustic emission signal, it is due to its non-stationarity. It is difficult to use the traditional signal analysis technology to interpret the acoustic emission signal comprehensively, systematically and effectively. What method can be used to understand the energy change with the destruction process of water-bearing rock has become a hot issue for experts and scholars all over the world. The uniaxial compression test was carried out for the rock of degree degree. The acoustic emission data in the process of destruction are obtained, and then the change rule of the number of sandstone acoustic emission events with the change of saturation is studied. Secondly, the wavelet packet transform is used to process the acoustic emission signal. The advantages and disadvantages of wavelet analysis and wavelet packet analysis are compared. The characteristics of energy band distribution of acoustic emission signal of water-bearing rock are studied. The variation law of energy frequency band before and after rupture is compared and the main frequency band in the process of failure of water-bearing rock is found. Thirdly, according to the principle of energy. According to the time series and signal singularity, the Lipschitza value is calculated by wavelet packet decomposition and reconstruction, and the time points in the time series corresponding to the minimum 偽 value are taken as the time of water-bearing rock fracture. Finally, according to a matrix can be completely represented by all its eigenvector, and each vector corresponding to the eigenvalue. This theory represents the contribution rate of matrix on this vector, based on the fact that when the signal changes, the frequency components of the signal will have different suppression or enhancement effects, compared with the non-broken signal. The energy of some frequency bands will surge in a short period of time before rupture, and the energy in some frequency bands will be suddenly reduced. The acoustic emission signal will be decomposed into wavelet packets and reconstructed to obtain the wavelet packet node coefficients. The eigenvalue of the wavelet packet node coefficient is obtained by using the wavelet packet node coefficient as the eigenvector. Although the energy of acoustic emission signals of rock samples in laboratory is different from that of rock mass in engineering, the variation of rock samples is not different from that of rock samples in engineering. This paper has practical guiding significance for damage process, development trend and fracture prediction of water-bearing rock.
【學(xué)位授予單位】：東北大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TU45

【共引文獻(xiàn)】

相關(guān)期刊論文 前10條

1 呂軍;呂勇;;雙向正交共軛濾波器的構(gòu)造[J];安康學(xué)院學(xué)報;2012年03期

2 成麗波;;小波分析方法在圖像壓縮中的應(yīng)用[J];長春理工大學(xué)學(xué)報(自然科學(xué)版);2011年04期

3 劉江利;陳健;謝永興;;基于小波分析的濁度傳感器故障診斷研究[J];傳感器與微系統(tǒng);2011年08期

4 殷文彥;黃聲享;刁建鵬;;超高層傾斜建筑周日變形監(jiān)測數(shù)據(jù)分析[J];測繪信息與工程;2008年02期

5 劉曉安;王金文;王海偉;;基于小波分析的月徑流ARIMA預(yù)測方法[J];水電自動化與大壩監(jiān)測;2006年04期

6 史曉峰;顧海燕;馬曉劍;;基于Marr小波在水文中的應(yīng)用[J];東北林業(yè)大學(xué)學(xué)報;2008年06期

7 張曉冰;崔家瑞;梁原華;王慕坤;;畸變信號條件下有功功率的計量方法分析[J];電測與儀表;2006年12期

8 王東舉;周浩;;高壓輸電線路故障定位綜述[J];電氣應(yīng)用;2007年04期

9 王曉，

本文編號：1425340