基于压电超声导波能量分析法的管道结构腐蚀损伤监测研究

发布时间：2018-01-16 18:33

本文关键词：基于压电超声导波能量分析法的管道结构腐蚀损伤监测研究　出处：《沈阳建筑大学》2015年硕士论文　论文类型：学位论文

【摘要】：管道结构在石油、电力、化工行业以及在城市供水系统中发挥着重要的作用。在铁路、水路、公路、民航、管道运输等五大运输方式中,管道运输以低成本、大运量、少污染为优势,逐渐成为五大运输业之首。现如今,我国大部分的石油和天然气都由管道运输,因此管道运输业在经济建设及城市供水等方面起着重要的作用。但随着使用年限的增加以及环境的腐蚀因素,管道结构逐渐发生裂纹或者腐蚀损伤,由此引起的泄漏爆炸事件在近年来逐渐增加。这不仅给人民生命安全带来了危害,还会造成严重的环境污染。由此可见,定期对在役管道进行定期安全检查迫在眉睫。针对常规检测方法无法对长距离、大范围的管道结构进行全面检测的缺点,一种新的无损检测方法——利用压电陶瓷的超声导波检测方法被发展起来,并受到广泛关注。本文将理论分析、试验验证和数值模拟相结合,并在此基础上,对无损伤空心钢管以及具有腐蚀损伤的空心钢管结构进行了检测研究。首先,对空心圆管结构中的导波理论进行了推导,得出了柱面导波和周向导波的频散方程,并利用Matlab软件对导波的频散方程进行求解,绘制出所需尺寸管道的群速度和相速度频散曲线；然后,对管中传播导波的多种模态进行分析,确定了适宜在管中传播的超声导波模态及激励频率,尽可能使导波的频散最小,以削弱管道回波信号分析时的复杂性,为管道检测时导波信号的选取提供了理论依据。其次,根据脉冲回波法,本文对空心钢管进行了验证性试验。通过对激励信号的分析发现,随着信号周期数目的增大,频带逐渐窄,这更有利于控制信号频率,但另一方面,在时域内信号持续时间较长,波形容易叠加,综上所述,本文选用经Hanning窗调制的7周期的正弦叠加信号作为实验的激励信号。利用智能材料——压电陶瓷作为信号的激励与信号的接收装置,建立了一套快捷有效的试验系统。利用这套试验系统,分别对无损管道以及具有腐蚀性损伤的管道进行检测,探究其规律。最后,本文利用ABAQUS软件分别对无损管道、具有腐蚀损伤管道进行了数值模拟。给出导波在管道中的能量衰减规律,并且分析了腐蚀损伤径向深度及轴向长度的变化对管道损伤程度的影响。结果表明,管道的损伤程度与腐蚀损伤径向深度及轴向长度基本成线性变化。将模拟结果与试验结果进行对比验证,表明两者基本吻合,从而验证了数值模拟以及试验方法的准确性、实用性。
[Abstract]:Pipeline structure plays an important role in petroleum, electric power, chemical industry and urban water supply system. Among the five modes of transportation, such as railway, waterway, highway, civil aviation and pipeline transportation, pipeline transportation is of low cost. Nowadays, most of the oil and gas in our country are transported by pipeline. So pipeline transportation plays an important role in economic construction and urban water supply, but with the increase of service life and environmental corrosion factors, pipeline structure gradually crack or corrosion damage. The leakage and explosion caused by this has increased gradually in recent years, which not only brings harm to people's life and safety, but also causes serious environmental pollution. It is urgent to carry out regular safety inspection on the pipeline in service on a regular basis. In view of the shortcoming that the conventional inspection method can not carry on the comprehensive inspection to the long-distance, large-scale pipeline structure. A new nondestructive testing method, ultrasonic guided wave detection method using piezoelectric ceramics, has been developed and widely concerned. In this paper, theoretical analysis, experimental verification and numerical simulation are combined, and on this basis. The non-damage hollow steel tube and the hollow steel tube structure with corrosion damage are tested and studied. Firstly, the guided wave theory in the hollow circular pipe structure is deduced. The dispersion equations of cylindrical guided waves and circumferential guided waves are obtained, and the dispersion equations of guided waves are solved by Matlab software, and the dispersion curves of group velocity and phase velocity are drawn. Then, by analyzing the various modes of guided wave propagation in the tube, the mode and excitation frequency of ultrasonic guided wave which is suitable for propagation in the tube are determined, so as to minimize the dispersion of the guided wave as far as possible. In order to reduce the complexity of the pipeline echo signal analysis, it provides a theoretical basis for the selection of the guided wave signal in pipeline detection. Secondly, according to the pulse echo method. Through the analysis of the excitation signal, it is found that with the increase of the number of signal cycles, the frequency band is gradually narrow, which is more conducive to the control of the signal frequency, but on the other hand. In the time domain, the signal duration is longer, and the waveform is easy to superposition. In this paper, the sinusoidal superposition signal modulated by Hanning window is selected as the experimental excitation signal, and the intelligent material-piezoelectric ceramic is used as the excitation and signal receiving device. A set of fast and effective test system is established. Using this test system, the non-destructive pipeline and the pipeline with corrosive damage are tested, and the rules are explored. In this paper, the numerical simulation of pipeline with corrosion damage and non-destructive pipeline is carried out by using ABAQUS software, and the law of energy attenuation of guided wave in pipeline is given. The influence of radial depth and axial length of corrosion damage on the damage degree of pipeline is analyzed. The damage degree of pipeline basically changes linearly with the radial depth and axial length of corrosion damage. The accuracy and practicability of numerical simulation and test method are verified.
【学位授予单位】：沈阳建筑大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU990.3;TU317

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