基于惯导原理地下管道三维测量系统软件设计

[目的]旨在解决针对传统物探方法诸如管线仪、探地雷达、声波探测仪等受其技术的局限性无法精确测定已有非开挖管线诸如小管径、大埋深、非金属管线得到的空间位置的难点,避免在施工过程中因为无法精确测定管线空间位置导致的事故频发的现象。[方法]针对非开挖管线探测的难题,提出以惯导为原理的探测技术对小管径、大埋深、非金属进行探测,并对以惯导原理为基础的地下管道三维测量系统进行软件设计及试验。[结果]试验成果表明:基于惯导原理地下管道三维测量系统软件结构及功能设计合理,针对非开挖管线测量可实时解算管道实际空间三维轨迹;测量过程中可以现场实时显示管道的空间轨迹俯视图、剖视图及三维空间视图,测量成果数据可存储输出,输出数据格式可根据不同需求进行设置,满足数字化地理信息三维数据管理系统输入要求,测量结果可较好的进行直观展示。[结论]该系统可适用于超埋深、小管径、任何材质的管道探测中,且其探测精度高,为城市疑难管线探测提供了较好的参考依据。     

超高压水晶釜超声相控阵检测技术探讨

针对内外径比0.8的厚壁圆筒结构超高压水晶釜,常规的超声检测技术存在缺陷定位困难、灵敏度不高、釜底螺牙无法检测等难题,且国内外暂无相应的检测标准和成熟工艺可依。通过利用相控阵技术可灵活地实现声束的聚焦和偏转、高分辨力、超声成像等优点,提出采用超声相控阵技术对超高压水晶釜釜体进行检测,能可靠的检测出釜体缺陷的位置、尺寸以及分布成像。     

焊缝相控阵超声检测读谱——ASME规范应用案例

介绍按ASME规范（09增补版）要求,用超声相控阵技术检测承压设备焊缝时,根据相控阵扇形（S-）扫描图像结合相应探测布置截面图,对常见焊接缺陷检测图谱进行识别和评定的应用案例。所涉及的焊接接头为V型坡口单面焊和T型接头组合焊,焊接缺陷包括：焊趾裂纹、焊道下裂纹、内表面开口裂纹、坡口未熔合、根部未焊透、以及密集气孔等。同时,还比较了相控阵检测的定量结果与实际缺陷尺寸。目的是依据规范为焊缝相控阵超声检测图像识别和结果评定提供借鉴。     

探地雷达在隧道衬砌及公路无损检测中的应用研究

针对隧道衬砌及公路铺设质量为研究对象,利用探地雷达方法进行探测,介绍透射剖面法的方法原理,探讨探地雷达的应用范围,结合实验模型及工程实例,探讨探地雷达在在公路质量和隧道衬砌无损检测的应用的可靠性及其技术特点.     

锅炉焊缝相控阵超声检测典型图谱识别

介绍按ASME规范（09增补版）要求,用超声相控阵技术检测锅炉焊缝时,根据相控阵扇形（S-）扫描图像结合相应探测布置截面图,对典型焊接缺陷检测图谱进行识别和评定的应用案例。所涉及的焊接接头为相比于一般X型坡口双面焊是有一定检测难度的V型坡口单面焊和T型接头组合焊,焊接缺陷包括：焊趾裂纹、焊道下裂纹、内表面开口裂纹、坡口未熔合、根部未焊透、以及密集气孔等。同时,还比较了相控阵检测的定量结果与实际缺陷尺寸。目的是依据规范和标准要求,为锅炉焊缝相控阵超声检测图像识别和结果评定提供借鉴。     

管道渗漏区探地雷达响应特征分析

探地雷达在供水管道渗漏区探测方面具有广阔的应用前景。为增强渗漏区探地雷达响应特征的认识，提高渗漏区定位精度，基于时域有限差分法，模拟金属管道底部渗漏的探地雷达响应特征，并提取“三瞬”地震属性进行分析。结果表明，渗漏区上边界信号易识别，内部信号存在多次反射和震荡现象；渗漏区瞬时振幅属性与原始剖面反映效果相似，瞬时相位属性同相轴错断明显，瞬时频率属性明显衰减；瞬时相位属性和瞬时频率属性对渗漏区的存在及微弱信号反映效果较好，故渗漏区瞬时属性分析时优选瞬时相位属性和瞬时频率属性。结果可为探地雷达管道渗漏区探测图像解译和实际工程应用提供参考。     

承压设备焊缝超声相控阵检测读谱

介绍按ASME法规最新版（2009增补版）要求，用超声相控阵技术检测承压设备焊缝时，根据相控阵扇形（S－）扫描图像结合相应探测布置截面图，对典型焊接缺陷检测图谱进行识别和评定的应用案例．所涉及的焊接接头为相比于一般X型坡口双面焊是有一定检测难度的V型坡口单面焊和T型接头组合焊，焊接缺陷包括：焊趾裂纹、焊道下裂纹、内表面开口裂纹、坡口未熔合、根部未焊透、以及密集气孔等。同时，还比较了相控阵检测的定量结果与实际缺陷尺寸。目的是依据相关法规和标准要求，为承压设备焊缝相控阵超声检测图像识别和结果评定提供有用借鉴。     

基于BIM技术的混凝土面板堆石坝脱空检测与加固

在混凝土面板堆石坝施工和使用过程中,砼面板与垫层料两种不同特性材料之间可出现脱空缺陷。为优化混凝土面板堆石坝脱空缺陷的探测与加固技术,提出了一种基于探地雷达探测图像生成精确BIM模型的新方法。依据白云混凝土面板堆石坝的脱空缺陷探测与加固工程,应用BIM建模与Revit二次开发,结合探地雷达对混凝土面板堆石坝进行了全断面、全方位覆盖探测,生成了脱空病害分布的三维图,统计出脱空区域总体积,为治理混凝土面板堆石坝脱空病害提供了三维可视化的展示与精确的数据支撑,进而制定了有效的加固措施,并取得了良好的加固效果。     

超声相控阵技术对小口径接管座角焊缝检测研究

针对小口径接管座常规超声检测中的缺陷波识别难度大和内部缺陷易漏检的特点,在小口径接管座角焊缝检测中采用了超声相控阵检测技术,主要在超声相控阵检测角焊缝优势、相控阵探头选择、试块选择、聚焦法则设置、距离-幅度曲线的制作、角度增益补偿、声束覆盖模拟、缺陷图像数据分析以及工程应用方面进行了研究。结果表明:超声相控阵检测装置操作简单、灵活,小口径接管座角焊缝相控阵检测技术能够比较直观的显示缺陷的特性,为缺陷定性提供了技术依据,保证了小口径接管座角焊缝质量安全。     

混凝土结构内部缺陷超声波CT检测图像特征

根据超声波CT原理,通过试验研究了混凝土内部不同尺寸、形状缺陷的检测效果以及不同的测试方法和不同的测线密度情况下对混凝土缺陷CT图像的影响。试验结果表明,在合理布置测线的情况下,超声波CT可精确、直观地反映出混凝土的内部缺陷;另外在相同布置方式下,增加射线密度图像重建效果明显改善。     

Simulation of ultrasonic phased array technique for imaging and sizing of defects using longitudinal waves

Phased array ultrasonics can be used as a rapid tool for imaging and sizing crack-like defects. This paper reports the simulation of phased array ultrasonic wave interaction with the defects using the finite-difference time domain (FDTD) method. Experiments were conducted to validate modeling results for pulse–echo simulations of the phased array transducer on a mild-steel (MS) pipe sample with circumferential internal surface notches of three different sizes. Experiments were carried out on the MS pipe specimen using a conventional ultrasonic technique with a 5 MHz transducer at 45° refracted angle within the specimen and the defects were imaged and sized using the relative arrival time technique (RATT). The experimental B-scans obtained using the conventional ultrasonic techniques were compared with the experimental B-scans obtained using the phased array instrument. Simulation studies were also carried out by steering the beam to the requisite angles by the phased array transducer to study the effect of various angles of incidence on the defect definition, i.e., with respect to imaging and sizing, using the RATT.     

Research on data diagnosis method of acoustic array sensor device based on spectrogram

Acoustic array sensor device for partial discharge detection is widely used in power equipment inspection with the advantages of non-contact and precise positioning compared with partial discharge detection methods such as ultrasonic method and pulse current method. However, due to the sensitivity of the acoustic array sensor and the influence of the equipment operation site interference, the acoustic array sensor device for partial discharge type diagnosis by phase resolved partial discharge (PRPD) map might occasionally presents incorrect results, thus affecting the power equipment operation and maintenance strategy. The acoustic array sensor detection device for power equipment developed in this paper applies the array design model of equal-area multi-arm spiral with machine learning fast fourier transform clean (FFT-CLEAN) sound source localization identification algorithm to avoid the interference factors in the noise acquisition system using a single microphone and conventional beam forming algorithm, improves the spatial resolution of the acoustic array sensor device, and proposes an acoustic array sensor device based on the acoustic spectrogram. The analysis and diagnosis method of discharge type of acoustic array sensor device can effectively reduce the system misjudgment caused by factors such as the resolution of the acoustic imaging device and the time domain pulse of the digital signal, and reduce the false alarm rate of the acoustic array sensor device. The proposed method is tested by selecting power cables as the object, and its effectiveness is proved by laboratory verification and field verification.     

Study on inserted curved surface coupling phased array ultrasonic inspection of multi-layered steel vessel for high-pressure hydrogen storage

Multi-layered steel vessel (MLSV) for high-pressure hydrogen storage is an important equipment in hydrogen refueling station and periodic inspection is necessary to be carried out on it. Welded joint between the head and thick-walled nozzle of the vessel is the key point of the inspection. In this study, based on structural characteristics of MLSV, a method of inserted curved surface coupling phased array ultrasonic inspection (PAUI) was proposed. In order to achieve effective inspection on the welded joint, acoustic field calculation model of the welded joint by PAUI was established. Influences of various inspection parameters on the acoustic field were analyzed by considering difficulties of far detection distance, wide detection area and large material attenuation systematically to obtain optimized parameters and scanning method. Corresponding probe was subsequently made according to the analysis, and experiment was carried out on test block to prove effectiveness of the method in this study.     

基于视频图像处理技术的火焰识别算法

针对现有的真火训练评估系统难以直接准确评价出实际灭火效果,以及部分真火训练环境比较空旷的特点,提出了一种基于视频图像处理技术识别火焰的算法,该算法能够直接检测出火焰大小,从而实现对训练效果更加直观准确的评估。通过对比分析的方法,确定采用YCbCr彩色模型算法,该算法拥有其自身独特的优点,即减轻改变照明度造成的负面影响并且提高火焰检测的准确率。为提高评估的准确性,针对火灾检测技术的难点和关键点提出了基于视频图像的解决办法,即先对火焰的圆形度、火焰边界的粗糙度和尖角个数分别进行特征提取,再进行动态特征提取,完成数据归一化处理。采取训练集对分类器展开训练,再根据训练集得到的模型对测试集进行预测,最终获取分类识别率。以某实际真火训练的1000张图片为样本,对模型中的火焰图像处理效果进行验证。实验结果表明:基于饱和度的规则和颜色模型能够更准确地体现火焰行为,在不利的照明背景条件下其鲁棒性更强。对比激光束检测、超声波检测和水量检测等方法,基于图像的火焰识别评估方式具有不易变形、定量直观、准确性高及操作方便等优点。     

基于多层感知器的气液两相流流型识别方法

通过对电阻层析成像数据采集原理和深度学习网络的研究,提出了一种基于阵列电阻值和多层感知器深度学习网络相结合的流型识别方法。利用电阻层析成像系统中的16个电极传感器来获取流型样本数据,并构建出流型识别数据库,然后对多层感知器深度学习网络进行训练,获得可以识别不同流型的网络。实验结果表明,采用阵列电阻值结合多层感知器网络对流型进行学习和识别的方法,流型识别准确率可以达到95%,解决了流型图像生成过程与数据特征预选过程中流型特征损失的问题,流型识别性能得到了提高。     

Frontiers in NDE research nearing maturity for exploitation to ensure structural integrity of pressure retaining components

In this paper, research and developmental efforts that demonstrate high sensitivity detection and characterization of defects and assessment of microstructural degradation, residual stresses and fatigue damage in materials using different non-destructive evaluation (NDE) techniques, have been discussed. Applications of eddy current techniques for quantitative defect characterization and for generalized applications, and remote field eddy current technique for inspection of steam generator and heat exchanger tubes have been discussed. Advanced ultrasonic methods such as time of flight diffraction, synthetic aperture focusing technique, phased array and signal processing for detection, characterization and imaging of defects have been discussed. Applications of ultrasonics and magnetic Barkhausen emission techniques for characterization of microstructures and residual stresses have been discussed. Applications of acoustic emission and infrared thermography techniques for weld quality evaluation of critical nuclear components as part of intelligent processing of materials (IPM) work have been discussed. Application of acoustic emission technique for integrity assessment of pressurized components has been discussed. Development of a software called assets and infrastructure management system (AIMS), for storing and retrieving information for various materials, components and systems, has also been highlighted. The techniques and applications discussed are result of systematic and innovative R&D efforts in the multidisciplinary areas of physics, materials, instrumentation, sensors and softwares for providing solutions to various challenging problems.     

The use of acoustic emission methods as aids to the structural integrity assessment of nuclear power plants

Since it is an integral method permitting continuous monitoring and remote defect location, acoustic emission offers promising benefits for the nuclear industry. Particular potential applications relating to the integrity of the primary pressure boundary of nuclear reactors that are considered in this report are the detection of flaws during pre-service and requalification hydrotests, and continuous monitoring for crack growth and leakage.The correlations between fracture mechanics and acoustic emission are discussed on the basis of certain fundamentals of material emission behaviour. The influence of instrumentation and of aspects related to wave propagation on the detectability and evaluation of acoustic emission signals is considered.The conclusion reached is that at the present time acoustic emission can be used predominantly during hydrotests as a search method for cracks. Although some degree of characterization and sizing of defects may be obtained on the basis of empirical data, a quantitative evaluation of defect severity based on fracture mechanics cannot yet be made satisfactorily. It is expected that a considerable improvement in this respect may be achieved by applying a transfer correction that takes into account the depth position and directivity pattern of the source.The technique of leak detection by acoustic emission shows promising results permitting the location and quantification of leaks. Practical experience and future research work are expected to enhance the accuracy and detection sensitivity.     

混凝土中弹性波传播频漂特性数值仿真与试验分析

为提高声发射技术在混凝土结构损伤检测中的准确度,针对弹性波在混凝土介质中传播出现的频漂现象,采用有限元数值模拟和试验研究了混凝土梁结构中弹性波传播的频漂特性,基于Hilbert-Huang变换中的Hilbert边际谱,分析了仿真和试验结果中不同频率段的频率衰减特性,取得了较好的一致性,即频漂具有自相似性和整体性两大特点,其中自相似性体现为不同宽度频率段的频率成分均近似呈指数型衰减,且频率段频率越高,衰减系数越大;整体性则体现为主频随传播距离的增加快速向低频移动。     

超声相控阵技术在聚乙烯管道电熔接头上的应用

由于聚乙烯材料声波衰减系数大，再加上电熔接头中金属丝信号对检测的干扰，使得传统的超声检测方法并不能有效检出聚乙烯电熔接头中的各类缺陷。笔者采用超声相控阵技术及B扫描实时成像技术，通过足够数量的探头排列和触发时间控制，并选用不同频率范围，可以实现对电熔连接接头缺陷的检测，