基于时间反转导波的管道缺陷检测研究

发布时间：2018-04-03 20:28

本文选题：管道检测　切入点：超声导波　出处：《哈尔滨工业大学》2015年硕士论文

【摘要】：管道普遍存在于海洋工程、电力、化工、城市建设等行业中。在长期运营过程中,不可避免的会出现各种各样的缺陷,造成安全隐患,需要对管道定期进行检测。超声导波技术具有检测距离长、效率高、成本低的特点,可用于工业管道损伤检测。本文基于空心圆管柱面导波基本理论,采用理论分析、数值模拟以及实验验证的方法,运用时间反转导波方法对管道缺陷检测检测进行研究,主要内容如下:运用有限元软件ABAQUS对管道周向裂纹缺陷和圆孔型通透型缺陷进行时间反转导波检测。结果表明,与直接导波检测相比,时间反转导波可以检测更小的缺陷;在时间转导波检测中,截取缺陷回波信号的窗宽是影响时间反转导波检测能力的重要因素。研究了缺陷反射率随周向裂纹缺陷的深度、周向长度和圆孔型缺陷的半径的变化规律。搭建了基于Labview虚拟仪器的管道超声导波缺陷检测系统,实验验证了时间反转导波可显著提高缺陷检测能力,可以检测更小的缺陷。对不同尺寸的槽型缺陷和圆孔缺陷进行了实验研究,得到了缺陷反射率随周向裂纹缺陷的深度、周向长度和圆孔型缺陷的半径的变化规律。运用基于激励波形的匹配追踪算法对单缺陷和双缺陷的缺陷回波进行了分解重构。结果表明,根据分解原子的系数正负号的异同可识别出单缺陷与双缺陷,原子的时间间隔准确反映了单缺陷的轴向宽度和双缺陷的轴向间距。
[Abstract]:Pipeline widely exists in marine engineering, electric power, chemical industry, urban construction and other industries.In the long-term operation process, there will inevitably be a variety of defects, resulting in hidden safety problems, the pipeline needs to be tested regularly.Ultrasonic guided wave technology has the characteristics of long detection distance, high efficiency and low cost, so it can be used in industrial pipeline damage detection.In this paper, based on the basic theory of cylindrical guided wave of hollow pipe, the method of theoretical analysis, numerical simulation and experimental verification is used to study the detection of pipeline defects by time-reversal guided wave method.The main contents are as follows: using the finite element software ABAQUS to detect the circumferential crack defect and the circular hole permeable defect in time reversal guided wave.The results show that time reversal guided wave can detect smaller defects than direct guided wave detection, and the window width of intercepting defect echo signal is an important factor that affects the detection ability of time reversal guided wave in time transduction wave detection.The variation of defect reflectivity with the depth of circumferential crack defect, circumferential length and radius of circular hole defect is studied.An ultrasonic guided wave defect detection system based on Labview virtual instrument is built. The experimental results show that the time reversal guided wave can significantly improve the ability of defect detection and can detect smaller defects.In this paper, the groove and circular hole defects of different sizes are experimentally studied, and the variation of defect reflectivity with the depth of circumferential crack defect, circumferential length and radius of circular hole defect is obtained.A matching tracking algorithm based on excitation waveform is used to decompose and reconstruct the defect echo of single defect and double defect.The results show that the single defect and the double defect can be identified according to the differences and similarities of the coefficients of decomposition atom, and the time interval of the atom accurately reflects the axial width of the single defect and the axial spacing of the double defect.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U178

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