本文選題：波動(dòng)理論 + 聲發(fā)射傳播��； 參考：《沈陽工業(yè)大學(xué)》2016年碩士論文

【摘要】：隨著經(jīng)濟(jì)的發(fā)展,石油儲罐的安全越來越重要。由于儲存介質(zhì)的特殊性,特別容易引發(fā)罐底板腐蝕而導(dǎo)致安全隱患。聲發(fā)射檢測是檢測儲罐底腐蝕的有效手段。本文主要通過仿真實(shí)驗(yàn),對罐底板聲發(fā)射信號的波形與傳播特性進(jìn)行了研究。本文對聲發(fā)射本質(zhì)與波動(dòng)理論進(jìn)行了歸納,確立使用波動(dòng)理論解決聲發(fā)射問題。針對罐底板這種復(fù)雜結(jié)構(gòu)中的波動(dòng),使用有限元方法并采用COMSOL有限元軟件進(jìn)行仿真。對聲發(fā)射激勵(lì)信號進(jìn)行了總結(jié),對罐底板模型在仿真中參數(shù)選擇進(jìn)行了分析,使用結(jié)構(gòu)力學(xué)-固體力學(xué)模塊,求解采用瞬態(tài)分析方法。運(yùn)用有限元仿真軟件,首先對板中Lamb波進(jìn)行仿真,確立仿真對象與研究重點(diǎn)。再對罐底板分別進(jìn)行二維、三維無焊縫模型、三維有焊縫模型的仿真。選取不同采樣點(diǎn)的應(yīng)力、位移分量,應(yīng)用分段濾波與小波時(shí)頻圖方法進(jìn)行分析。通過上述理論與仿真研究表明,在頻譜段上,聲發(fā)射在低頻信號能量最大,但包含信息較少,在100kHz為激勵(lì)的信號中,20-80kHz信號最為豐富,能量較100kHz以上信號大,信息量較多。50kHz左右信號在波形與小波時(shí)頻圖上也與實(shí)際采集的聲發(fā)射信號最為吻合,說明采集中主要采集的就是聲發(fā)射50kHz左右信號。在激勵(lì)信號上,二維仿真中使用階躍信號產(chǎn)生了多道脈沖,與Lamb實(shí)驗(yàn)相似,在三維仿真中,則使用脈沖信號,信號隨時(shí)間衰減。在方向上,在底板固定的情況下,法線方向能量強(qiáng)度最高,最適合聲發(fā)射采集。同時(shí),底板中焊縫對聲發(fā)射信號傳播影響也很大。
[Abstract]:With the development of economy, the safety of oil storage tanks is becoming more and more important. Because of the particularity of storage medium, it is easy to cause tank floor corrosion and lead to hidden danger of safety. Acoustic emission detection is an effective method to detect tank bottom corrosion. In this paper, the waveform and propagation characteristics of acoustic emission signals from tank floor are studied by simulation experiments. In this paper, the essence of acoustic emission and wave theory are summarized, and the wave theory is used to solve the acoustic emission problem. The finite element method (FEM) and COMSOL finite element software are used to simulate the wave in the complex structure of tank floor. The acoustic emission excitation signal is summarized and the parameter selection of the bottom plate model of the tank is analyzed in the simulation. The structural mechanics solid mechanics module is used to solve the problem and the transient analysis method is used to solve the problem. In this paper, the finite element simulation software is used to simulate the Lamb wave in the plate, and the simulation object and research emphasis are established. Then the tank bottom plate is simulated by two-dimensional, three-dimensional weld-free model and three-dimensional weld model. The stress and displacement components of different sampling points are selected and analyzed by using piecewise filtering and wavelet time-frequency image method. The theoretical and simulation results show that in the frequency spectrum, acoustic emission has the largest energy in the low frequency signal, but contains less information. Among the signals excited by 100kHz, the 20-80kHz signal is the most abundant, and the energy is larger than that of the 100kHz signal. The more information about .50kHz signal is the most consistent with the actual acoustic emission signal on the waveform and wavelet time-frequency diagram, which shows that the main acquisition is the acoustic emission 50kHz signal. In the excitation signal, the step signal is used to generate multi-channel pulse in two-dimensional simulation, which is similar to the Lamb experiment. In three-dimensional simulation, the pulse signal is used, and the signal attenuates with time. In the direction, the normal direction energy intensity is the highest when the bottom plate is fixed, so it is most suitable for acoustic emission acquisition. At the same time, the weld in the bottom plate also has a great influence on the acoustic emission signal propagation.
【學(xué)位授予單位】：沈陽工業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2016
【分類號】：TE988

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 章欣;馮乃章;王艷;沈毅;;鋼軌裂紋傷損聲發(fā)射源的建模仿真與特征分析[J];聲學(xué)學(xué)報(bào);2015年04期

2 邱楓;戴光;張穎;趙永濤;張明宇;;儲罐底板腐蝕聲發(fā)射源的識別定位[J];無損檢測;2015年02期

3 徐渠;;基于超聲Lamb波技術(shù)的儲罐底板缺陷檢測分析[J];宿州教育學(xué)院學(xué)報(bào);2014年06期

4 張志強(qiáng);張國勝;劉艷芳;王軍威;高素梅;;斷鉛試驗(yàn)聲發(fā)射信號處理與損傷源定位研究[J];中國測試;2015年08期

5 陳葦波;鐘舜聰;朱志彬;伏喜斌;;結(jié)構(gòu)聲發(fā)射的數(shù)值模擬及實(shí)驗(yàn)研究[J];機(jī)電工程;2014年05期

6 李忠紅;;儲罐底板聲發(fā)射安全檢測技術(shù)研究[J];石油化工自動(dòng)化;2013年04期

7 剛鐵;劉強(qiáng);;薄板結(jié)構(gòu)中Lamb波的檢測與仿真[J];無損檢測;2013年07期

8 李興霞;趙干;;10萬立方米大型油罐底板的焊接及其變形控制[J];現(xiàn)代焊接;2013年07期

9 黃志強(qiáng);王明波;王維斌;康葉偉;李琴;周已;;基于超聲Lamb波技術(shù)的儲罐底板缺陷檢測[J];科技導(dǎo)報(bào);2013年16期

10 鮑電;;影響220kV輸電線路工程造價(jià)敏感因素分析[J];安徽電氣工程職業(yè)技術(shù)學(xué)院學(xué)報(bào);2012年04期

，

本文編號：1922276