基于MATLAB的超声无损评价系统

信号２技术用于超声无损检测及评价，能大大提高检测的可靠性。本文建立了一个基于ＭＡＴＬＡＢ的集成化的超声波无损检测和无损评价系统，该系统休信号采集、分析、处理、评价于一体，还有典型缺陷库，用于超声波无损检测和评价时十分方便。系统不但具有常规信号处理功能，如滤波、频谱分析，而且能处理超声无损检测中的各种噪声，此外还能进行小波分析和小波包分析。该系统基于ＭＡＴＬＡＢ和Ｗｉｎｄｏｗｓ９５，有很强大的数值运     

定量无损检测不确定度的软校准方法

常规无损检测具有的不确定性难以满足工程实际中无损评价和可靠性安全分析的基本要求。采用测量不确定度评定方法、逆回归分析、无损检测模糊理论和数据融合方法建立了无损检测测量不确定度评定的软校准方法。针对工程实例进行的计算和分析表明,在无损检测仪器系统准确度不变的情况下,软校准方法能够使检测结果的随机不确定度大幅度降低、系统不确定度明显降低,弥补常规"硬校准"的部分缺点,明显提高数据品质,满足无损评价和可靠性安全分析、风险与寿命的设计基本要求。     

无损检测质量管理

对各种无损检测方法共同涉及到的无损检测质量管理问题进行了详细论述，包括如何建立无损检测质量管理体系，无损检测质量管理的职责，无损检测的资源管理及无损检测的过程管理等。     

无损检测仪器的可靠性预计

为了实现无损检测仪器研制阶段的可靠性评价，在样机设计及研制过程中开展了可靠性预计方法的探索，通过进行可靠性建模和数学计算，获得了可靠性预计值。结果表明，可靠性预计可以实现可靠性指标符合性的初步评估，进而为仪器研制阶段的可靠性设计优化提供参考。     

模糊理论在焊缝缺陷质量等评定的中应用研究

初步分析无员检测缺陷的质量等极评定中存在的模糊性。应用模糊理论，建立不同质量等极的隶属函数，并对具体无损检测结果作定量分析和评定。     

无损检测可靠性的评估方法

在分析影响无损检测可靠性因素基础上,介绍了无损检测可靠性的评估方法及提高无损检测可靠性的途径。     

海底管道无损检测技术评定中人工缺欠的制作

人工缺欠是无损检测技术评定研究的重要依据,人工缺欠的制作质量直接决定了无损检测技术评定结果的准确性和可靠性。研究了海底管道无损检测技术评定过程中所使用的人工缺欠的制作方法,通过预埋异物、改变焊接参数、机械加工等方法模拟在焊接过程中产生的自然缺欠,较精确地控制了人工缺欠的尺寸、位置及走向,提高了人工缺欠制作的合格率,并通过衍射时差法,射线检测以及破坏性试验等手段验证了缺欠的质量,从而为无损检测技术的评定提供高质量的人工缺欠试块。     

扩散连接接头质量评价现状

回顾扩散连接接头质量无损检测与评价的现状，介绍目前研究较多的超声反射法、超声信号处理、超声成像及实时监控等方法。由于扩散连接接头无损检测的复杂性，大多数检测技术还处于实验室研究阶段，因此，深入研究超声波与扩散连接界面的相互作用和先进的信号分析处理方法，对扩散连接接头质量的评价具有重要意义。     

发展无损检测中等职业技术教育的工作实践

随着工业生产的发展,无损检测技术已在愈来愈多的行业得到了广泛的应用。由于它在保证产品质量及机械设备运行可靠性方面的重要作用,已使这项技术在各国引起普遍重视,从某种意义上讲,无损检测技术水平的高低已代表了一个国家工业发展的水平。由于无损检测技术大多是采取相对测量或间接测量方法,由无损检测人员对检测结果做出解释、分析、评定与判断,人的因素直接影响无损检测结果的有效性。因此,大力培养受过正规、系统的专业基础理论和实践技能教育的无损检测人才,以提高无损检测人员的素质和技术水平,已成为进一步发展无损检测技术的必然。 目前,我国无损检测高等教育,经过十几年的发展,已经解决了有关问题,专业建设取得了很大的成绩。国内已有30多所高等院校和科研单位从事无损检测高级人才的培养工作。相比之下,国内无损检测专业的中等职业技术教育则十分薄弱,整个无损检测教育呈现倒金字塔形。因此,大力开展无损检测中等职业技术教育,为生产第一线培养更多的无损检测中等技术人才,已是势在必行。     

电子错位照相技术及其在材料无损检测中的应用

介绍了电子错位照相技术的基本原理、加载方法、相移技术、电子错位照相技术在材料无损检测中的发展及应用状况，并从检测的灵敏度、可靠性、检测效率等方面与其他传统无损检测方法进行了比较，说明电子错位照相技术是传统无损检测方法的一种有效补偿手段，最后提出了电子错位照相技术未来的发展趋势将是与专家系统相结合实现智能检测。     

Defect assessment on radiant heaters using infrared thermography

A non-destructive testing and evaluation technique (NDT&E) for the assessment of defects on radiant heaters is proposed in this paper. It is based on the analysis of infrared thermography images. Processing the images makes the location of defects easier and also allows its classification. Furthermore, using morphing algorithms, an automatic detection and evaluation of the defects is achieved. The technique can be used to perform an on-line fabrication quality control.     

Quantitative validation of Eddy current stimulated thermal features on surface crack

Thermography is an established technique in Non-Destructive Testing and Evaluation (NDT&E) for detecting and visualizing defects. The acquired thermal image sequences contain valuable information in the spatial, time and frequency domains. Many thermal feature extraction methods have been previously proposed to detect and quantify defects. However, the quantitative assessment and error analysis remain as challenges. In the present work, a quantitative analysis strategy is proposed for validating detection performance of various thermal feature extraction techniques based on Eddy Current Stimulated Thermography. F-score is adopted as a global quantitative evaluation indicator to assess the crack detectability. The quantitative validation is carried out based on a large number of simulations and experiments for cracks on the nonferromagnetic material. The detectability in relation to the variations in crack size and the different thermal feature extraction methods have been critically analyzed. The insights obtained from the present findings can serve as guidelines to other types of thermal-based NDT&E to improve the defect visibility and detectability.     

奥氏体不锈钢小径管焊接接头的相控阵超声检测

针对奥氏体不锈钢小径管焊接接头的检测难点,开展了专用试块设计、检测参数优化、检测能力验证、缺陷分析评定等相关技术的研究,总结形成了一套相控阵超声检测工艺和评定方法.检测工艺适用于外径为32～100 mm,壁厚为4～20 mm的奥氏体不锈钢小径管焊接接头的质量评定,通过在火力发电机组安装和检修工程中的成功应用,验证了该工...     

Non-destructive ultrasonic examination of root defects in friction stir welded butt-joints

As a solid-state welding process, Friction Stir Welding (FSW) offers a variety of advantages over traditional welding processes. Problems that are typically occurring due to the cooling of the liquid phase, such as solidification cracking and formation of porosity, generally do not occur in FSW. Nevertheless, as a result of suboptimal settings of the welding process parameters and certain uncontrollable conditions, FSWs are still associated with a number of specific flaws, e.g. root flaws and wormholes.Ultrasonic non-destructive testing and evaluation techniques (NDT&E) can be used for quality assessment of friction stir welded joints. In this paper, a novel approach for the detection of root flaws is proposed using an immersion ultrasonic testing method in oblique incidence and backscatter mode. The backscattered energy C-scan images obtained after an empirical positioning and proper time gating can be straightforwardly interpreted by direct comparison with typical ‘flaw’ patterns, allowing for identification and localization of the root flaws in the weld. The method is illustrated for FSW butt joints of the AlZnMgCu (7XXX series) alloy.     

Passive RFID sensor systems for crack detection & characterization

A significant requirement of low-cost sensor systems for defect detection and characterization is to bridge the gap of nondestructive testing & evaluation (NDT&E) and structural health monitoring (SHM). This paper introduces an ultra-high frequency (UHF) passive RFID sensor system for crack detection and potential structural monitoring. The working principles and major research challenges are presented for the new concept of NDT&E sensor systems. One novel approach using 3D antenna and kernel principal component analysis (PCA) is investigated and validated in conjunction with two case studies for evaluation of open and closed cracks. This proposed method can partly alleviate the nonlinearity from wireless channel and demonstrate the feasibility of the in-situ motoring through amplitude and phase of tag’s backscattered signals.     

超声相控阵技术的发展及应用

扼要介绍超声相控阵技术的发展历史、原理及特点。着重介绍其最新研究动态及其在核工业无损检测与评价中的典型应用。指出将相控阵技术同其它诸如纵波一发一收（TRL）、声时衍射（TOFD）技术、数字信号处理（DSP）及成像等技术结合起来，将有助于充分发挥其特点，提高其检测能力，促进无损检测与评价的发展及应用。     

Design of a stereoscopic X-ray imaging system using a single X-ray source

The design of a prototype binocular stereoscopic X-ray imaging system for a security screening application is presented. This is based on an innovative technique [Evans JPO, Robinson M, Godber SX. A new stereoscopic imaging technique using a single X-ray source: theoretical analysis. NDT&E International 1996;29(1):27–35] utilising a single X-ray source and a pair of linear X-ray detector arrays. The image data is collected whilst the object under inspection is linearly translated past the X-ray detectors. The machine constructed enables approximately one cubic metre of object space to be imaged in five seconds. The resultant images may also be used for the extraction of three-dimensional coordinate information.     

过程方法管理在无损检测中的应用

介绍了过程方法的定义及管理要素。论述了由于无损检测是鉴别特殊过程产品质量的一种手段,因而在无损检测过程中推行过程方法十分必要。过程方法使无损检测过程要素管理更加科学,过程分析更加严密,过程操作更加规范,业绩考核更加量化,因此能行之有效地确保产品质量和工作质量。     

无损检测广义可靠性及其研究方法

在地常规无损检测（ＮＤＴ）可靠性概念剖析的基础上,提出了ＮＤＴ广义可靠性的概念。针对影响ＮＤＴ广义可靠性的各类不确定因素,对广义可靠性研究的策略和途径进行了分析。重点介绍故障树分析、模糊综合评判以及可靠度类比分析等研究方法。