本文選題：聲發(fā)射 + 管道結(jié)構(gòu)��； 參考：《大連理工大學(xué)》2015年碩士論文

【摘要】：管道結(jié)構(gòu)作為一種廣泛應(yīng)用的工程結(jié)構(gòu),其承擔(dān)著重要的生產(chǎn)使命,需要長時間服役。管道結(jié)構(gòu)失效破壞,產(chǎn)生嚴(yán)重的負(fù)面影響甚至導(dǎo)致災(zāi)難發(fā)生,保證管道結(jié)構(gòu)的安全意義重大,對管道結(jié)構(gòu)進(jìn)行健康監(jiān)測是保證管道工程正常使用的最有效手段。管道結(jié)構(gòu)失效的最主要原因之一是管道腐蝕破壞,其不僅導(dǎo)致管道結(jié)構(gòu)承載能力的降低,甚至還直接導(dǎo)致管道結(jié)構(gòu)的腐蝕穿孔泄漏,是各類管道工程事故防范的重點。本文通過聲發(fā)射檢測技術(shù)對管道結(jié)構(gòu)腐蝕損傷進(jìn)行監(jiān)測研究,主要的內(nèi)容包括：(1)開展了鋼制管道腐蝕破壞聲發(fā)射監(jiān)測實驗研究。介紹了管道腐蝕機(jī)理,設(shè)計了鋼制管道加速電化學(xué)腐蝕實驗,整個實驗過程進(jìn)行了聲發(fā)射動態(tài)監(jiān)測,獲取了管道腐蝕損傷全過程聲發(fā)射監(jiān)測信號。通過聲發(fā)射信號特征參數(shù)分析,得出了管道腐蝕聲發(fā)射信號的特性,并將管道腐蝕過程劃分成腐蝕孕育期、腐蝕加速期、腐蝕穩(wěn)定期、腐蝕基本停滯期四個階段。通過波形分析,區(qū)分出了不同峰頻所對應(yīng)信號的波形特征和頻譜。(2)為了確定管道腐蝕損傷不同的聲發(fā)射源,對管道腐蝕聲發(fā)射信號進(jìn)行了聚類分析。首先進(jìn)行了管道腐蝕聲發(fā)射信號數(shù)據(jù)主成分分析,降低了信息冗余量。然后采用K均值算法和模糊C均值算法對管道腐蝕聲發(fā)射信號進(jìn)行了聚類分析并進(jìn)行了比較分析。通過二者的有效性分析確定了最佳聚類類別數(shù)。二者對管道腐蝕聲發(fā)射信號分類識別的結(jié)果完全一致,有效識別了管道腐蝕過程中的損傷源和噪聲源。根據(jù)各類信號的相關(guān)特征參數(shù)累積曲線,揭示了各類信號的發(fā)生發(fā)展過程,得到了管道腐蝕損傷源對應(yīng)的聲發(fā)射信號類別。(3)利用聲發(fā)射技術(shù)對管道腐蝕穿孔泄漏進(jìn)行了定位研究。首先研究了管道聲發(fā)射信號衰減特性,證實聲發(fā)射信號在鋼制管道上傳播特性良好。通過模擬天然氣管道泄漏過程,設(shè)計了高壓管道氣體泄漏檢測和定位實驗。分析了不同管道壓強下泄漏聲發(fā)射信號的特征；利用小波分析技術(shù)對泄漏信號進(jìn)行降噪處理,通過互相關(guān)函數(shù)法對去噪后的泄漏信號進(jìn)行了時延估計,采用時差定位法對泄漏源進(jìn)行了定位計算,取得了良好的定位精度。
[Abstract]:As a widely used engineering structure, pipeline structure takes on important production mission and needs long service. The failure and failure of pipeline structure have serious negative effects and even lead to disaster. It is of great significance to ensure the safety of pipeline structure. The most effective means to ensure the normal use of pipeline engineering is to monitor the pipeline structure healthily. One of the main causes of pipeline failure is pipeline corrosion, which not only reduces the bearing capacity of pipeline structure, but also directly leads to corrosion, perforation and leakage of pipeline structure, which is the key point of all kinds of pipeline engineering accident prevention. The main contents of this paper are as follows: (1) the experimental research on acoustic emission monitoring of steel pipeline corrosion damage is carried out. The corrosion mechanism of pipeline is introduced, and the accelerated electrochemical corrosion experiment of steel pipeline is designed. The acoustic emission dynamic monitoring is carried out in the whole process of the experiment, and the acoustic emission monitoring signal of the whole process of pipeline corrosion damage is obtained. By analyzing the characteristic parameters of acoustic emission signal, the characteristics of corrosion acoustic emission signal of pipeline are obtained, and the corrosion process of pipeline is divided into four stages: inoculation period, accelerated period, stable stage and stagnation stage. Through waveform analysis, the waveform characteristics and spectrum of the signals corresponding to different peak frequencies are distinguished. (2) in order to determine the different acoustic emission sources of pipeline corrosion damage, the pipeline corrosion acoustic emission signals are analyzed by cluster analysis. Firstly, the principal component analysis of pipeline corrosion acoustic emission signal data is carried out to reduce the information redundancy. Then K-means algorithm and fuzzy C-means algorithm are used to cluster and compare the corrosion acoustic emission signals of pipeline. The optimal number of clustering categories is determined by the validity analysis of the two methods. The results of classification and identification of acoustic emission signals of pipeline corrosion are consistent with each other, and the damage and noise sources in the corrosion process of pipeline are effectively identified. According to the cumulative curve of the characteristic parameters of all kinds of signals, the occurrence and development process of all kinds of signals are revealed. The acoustic emission signals corresponding to the corrosion damage source of pipeline are obtained. (3) the location of corrosion and perforation leakage of pipeline is studied by acoustic emission technology. Firstly, the attenuation characteristics of acoustic emission signal in pipeline are studied, and it is proved that the acoustic emission signal propagates well on steel pipe. By simulating the leakage process of natural gas pipeline, the gas leakage detection and location experiment of high pressure pipeline is designed. The characteristics of leakage acoustic emission signal under different pressure of pipeline are analyzed, the noise reduction of leakage signal is carried out by wavelet analysis technology, and the time delay of de-noised leakage signal is estimated by cross-correlation function method. The time difference method is used to locate the leakage source, and good positioning accuracy is obtained.
【學(xué)位授予單位】：大連理工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：U178

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本文編號：2083927