新千年的无损检测技术：从罗马会议看无损检测技术的发展方向

介绍在罗马召开的15届世界无损检测会议（WCNDT）的概况,简要阐述无损检测技术未来的发展方向。     

第17届世界无损检测会议欢迎您

2008年8月27-31日，第17届世界无损检测会议暨展览会将在上海召开。会议由国际无损检测委员会主办，中国机械工程学会无损检测分会承办。第17届世界无损检测大会暨展览会在我国召开，是中国无损检测界的骄傲，是老一辈无损检测工作者的多年夙愿，也是新一代无损检测工作者的热切心愿。     

高温作用后C20混凝土强度的无损检测

C20混凝土试块在450℃高温下持续不同时间后自然冷却，再对其进行超声、回弹综合法及标准抗压强度试验，以探讨同一高温不同时间作用后混凝土强度的变化规律，分析无损检测与标准抗压强度试验之间的关系。     

土木工程中的无损检测技术及其应用

土木工程中无损检测（简称ＮＤＴ－ＣＥ）有着广泛的应用和广阔的前景,ＮＤＴ－ＣＥ不仅用来对新建的建筑物进行质量监测,而且可对已有的建筑物结构的寿命进行评估,保养和修理。从应用的角度对ＮＤＴ－ＣＥ中常用的振动分析、冲击回波法、超声脉冲回波法、声发射、雷达、激光干涉以及红外线成像等技术的原理、应用局限性和发展前景作了简要介绍。     

第11届亚太地区无损检测会议概况

1　会议简介第11届亚太地区无损检测会议(11thAPC NDT)于11月3～7日在韩国济州岛召开,同时还举办国际无损检测仪器展览会。参加会议和展览的有来自15个国家和地区的400余代表和展商。学会组织了18人代表团参加会议,加上自行前往的代表,中国和日本一样,是外国代表中最大的群体。大会组织非常出色,所有安排都井井有条。针对目前无损检测的热点和前沿课题,大会邀请了一些知名专家作专题报告(如JRose,RBThompson和JAchenbach等),受到欢迎。会议报告非常守时,人们可以按时到不同会场听取自己需要的报告。大会还组织了一场以济州岛火山爆发…     

超声无损检测的应用研究与进展

对当前国内外超声无损检测技术的应用与研究进行了总结,展望了今后的发展趋势与前景。     

第17届世界无损检测会议暨展览会写真

金秋十月的上海展览中心迎来了第17届世界无损检测会议暨展览会隆重召开。在2008年10月24—28日,上海展览中心彩旗飘舞,气球悬空,红色拱门,长廊地毯,处处洋溢着盛大庄严的会议气氛。世界无损检测盛会终于如期而至,这里有中国无损检测人的企盼与自豪,有海外无损检测人的向往与遐想!四海无损检测人终于欢聚一堂,相会在中国,相会在上海,相会在上海展览中心!     

从APCNDT九届年会看声和超声检测技术的进展

本文简要介绍了今年三月在美国召开的亚洲和太平洋地区无损检测九届年会和同时召开的ＡＳＮＴ１９９８春季讨论会和第七届ＮＤＥ技术研讨会上,有关声和超声检测技术的进展情况。     

第十届亚太无损检测会议情况综述

介绍在澳大利亚召开的第10届亚太无损检测会议的概况，简要阐述了会议所揭示的一些无损检测技术未来发展动态。     

Application of neuro-fuzzy techniques in oil pipeline ultrasonic nondestructive testing

This paper presents a novel approach to the problem of nondestructive pipeline testing using ultrasonic imaging. The identification of the flaw type and its dimensions are the most important problems in the pipeline inspection. Unlike typical methods, a decision based neural network is used for the detection of flaws. We train a generalized regression neural network to determine the dimensions of the corrosions and generate the whole image of both the internal and external walls of the oil pipeline. As an improvement to the detection algorithm, we introduce fuzzy decision-based neural network algorithms for the detection and classification of the corrosions. The simulation and experimental systems results show that these new methods outperform the existing methods.     

New technique of nondestructive assessment of concrete strength using artificial intelligence

A new technique of nondestructively assessing the compression strength of concrete, which employs artificial neural networks, is presented. A data set based on results of testing concretes (with a 28-day strength of 24–105 MPa) by different nondestructive methods was used to train and test an artificial neural network. The methodology of neural identification of the strength is described. The obtained results, including those of the practical verification of the technique, are reported.     

Electrical resistivity measurement applied to cracking assessment on reinforced concrete structures in civil engineering

Non-destructive evaluation appears more and more important in the civil engineering economic stakes. In this context electrical resistivity measurements get sensitivity to parameters allowing to assess concrete structures conditions. This article analyses the ability of the resistivity measurement to study cracks in concrete. Its ability to detect and to locate cracks and spalling is shown with on site measurements on a damaged slab. Then specific studies on such disorders allow to distinguish the influence of their characteristics.The sensitivity of the method to cracks depth, according their moisture conditions, is assessed by computation. Experimental works on a reinforced concrete beam, ideally cracked, confirmed these results.Some assumptions based on measurements realised on a size-one structural component allow to assess the general influence of crack opening and bridging degree between crack lips.Qualitative results show the similar effects on measurement of various cracking parameters. Prospective works presented in the paper lead us to say that electrical resistivity method applied to civil engineering structures is a relevant tool for the assessment of structural damage.     

隧道衬砌裂缝深度检测中填充物影响的研究

在隧道衬砌裂缝深度检测及修补后的复检中,裂缝中往往会存在水、砂、水泥浆及裂缝灌浆树脂等填充物,有可能会对检测结果产生干扰。文章以德上高速第三方试验检测中心检测裂缝深度的试验模型及工程实例检测数据为基础,研究了裂缝中各种可能的填充物对检测结果的影响,对提高裂缝修补前后深度及饱满度检测结果的准确性,具有一定的参考价值。     

水冷壁管漏磁/超声无损检测机器人设计

根据电站锅炉水冷壁管的缺陷特征和运行环境,研究了管壁内外表面缺陷和壁厚减薄的磁性与超声波融合的无损检测方法。研制了一种能在管壁表面自动爬行的高效无损检测机器人系统,开发了相关的爬行机器人、磁化装置、检测装置、控制系统和缺陷数据分析与可视化软件。试验证明,磁性检测装置能完成锅炉在役管道的普查和缺陷定位,超声检测能有效实现局部缺陷的定量检测。该检测机器人系统具有很大的实用和推广价值。     

对工程项目中第三方无损检测工作模式的思考

介绍了实行第三方无损检测的优势与必要性,阐述了实际工作中实行第三方无损检测存在的问题与不足,提出了改进的措施。     

Optoelectronic nondestructive testing techniques of cocoon properties and applications

In this paper, cocoon properties are examined, spectral characteristics and mathematical expressions that define cocoon shell's absorption and reflection of light in various wavelengths are obtained and given in graphical form. Finally, optoelectronic methods and systems that determine cocoon properties are designed and explained.     

Utilization of two-directional AC current distribution for enhancing sizing ability of electromagnetic nondestructive testing methods

This paper proposes a novel method for accurately evaluating the depth of a defect using electromagnetic phenomena. The novel method induces AC currents inside a conductive medium and detects the disturbance of the currents. Whereas the principle itself has been utilized in conventional methods, the uniqueness of this new method lies in realizing a current distribution in which there is a region where currents near the surface and those deeply inside the specimen flow opposite to each other. The novel method provides a clear indication corresponding to the depth of the inspected defect. In addition, it enables one to evaluate the depth of a defect that is much deeper than the depth of penetration. After the physical background of this new method is explained, the results of experimental verifications and subsequent numerical simulations are presented.     

Online nondestructive testing for fine steel wire rope in electromagnetic interference environment

The diameter of fine steel wire rope (FSWR) is generally a few millimeters. Its magnetic flux leakage (MFL) signal is weak, and the number of magnetic sensors installed for defect detection is limited because of the small diameter. In FSWR production workshops, different kinds of machinery work together, deteriorating the power quality and making the spatial electromagnetic environment complex; the weak MFL is thus interfered with further. It is difficult to carry out online nondestructive testing (NDT) of FSWR in the process of manufacturing. In this paper we present a novel MFL method for FSWR NDT in a strong electromagnetic interference environment. We use a three-dimensional finite element method (FEM) to analyze the MFL signals. A simplified magnetic circuit is presented to excite the FSWR; the circuit comprises two half-sized radial magnetizing ring NdFeB magnets, and because there is no need for a magnetic yoke, the device is simple and light. A single Hall sensor is used to measure the flux leakage field. A stable performance power system is designed for the NDT power supply, which is not only resistant to voltage sags, but also has very low output noise. To enhance the signal-to-noise ratio (SNR) of the MFL defects signal, a signal conditioning and processing circuit are designed to enhance the detectability of signals in MFL data. The novel and small FSWR NDT system realizes on-line testing in an environment of strong electromagnetic interference, and for the experiment with a 1.5-mm-diameter wire rope twisted by 19 wires, the minimum damage of a pit on half of a wire can be identified.