外文翻译-相控阵列对比相控阵列-波束扫描对比编码数据采集

XX大学毕业设计文献翻译与原文题目： 相控阵列对比相控阵列-波束扫描对比编码 数据采集 学 院： 测试与光电工程学院专业名称： 测控技术与仪器班级学号： 学生姓名： 指导教师： 二Oxx 年 四 月 中文翻译相控阵列对比相控阵列-波束扫描对比编码数据采集J. 马克戴维斯1 与 迈克尔莫尔斯2 2加拿大奥林巴斯无损检测 ，加拿大，安大略省，多伦多，电话：(416) 831 442网络传真：(905) 248 -3546，邮箱：M,网址: 1J. 马克戴维斯, 戴维斯无损评价有限责任公司., 美国，亚拉巴马州,伯明翰, 电话:(205) 733 -0404，邮箱：, 网址:摘要本文描述了手动和编码相控阵列设备之间的不同。仅增加一个编码器在技术上不难实现，那么软件需求和优化的性能变得更为重要。由于规范或技术限制，很多无损检测应用领域无法用手动（或“波束扫描”）相控阵列装置来完成。引言人们有充分的理由相信，相控阵列是现今无损检测方向最热门的技术之一。与传统的超声波技术相比，相控阵列技术拥有明显的优势： 速度；对于焊缝，锈蚀和其他部件，线性（线路扫描）扫描可以大幅地提高扫描速 度（并且因此减少开支）。 成像；S-扫描，E-扫描和其他2D及3D成像能提供更好和更容易判断的缺陷评估。 灵活性；相控阵列可以对很多不同类型的部件所存在的多种多样的缺陷进行多种扫 描（1）。 数据存储；完整的甚或部分的数据存储和显示能容许更好的缺陷判读，外加可以用 于存档目的。 可重复性；尽管还未曾被第三方实验证实过，但使用同样的带有相控阵列的设备和 程序能比使用带有手动超声波的设备和程序提供更多的可重复性结果。然而，目前市场上可用的相控阵列设备远不止一种。除了早已应用了数十年的一款体积庞大且不方便携带的装置，仍有很多制造商生产便携式设备。便携式相控阵列设备本身可以划分成两类：手动的和编码的，两者的区别和性能很值得注意。本文描述了各种各样的特征和性能，并且提到了一些可以使用手动和编码设备的不同类型的应用领域。相控阵列技术在综述里提及，因此本文不会再详细描述。对物理成分，硬件，软件和应用样本的广泛评估，参见（1）波束扫描相控阵列设备波束扫描设备，如手动设备，操作起来就像也能扫描波束的高档单晶体设备一样。这些设备使用手动握持阵列，与手动探测器使用方式一样，例如，阵列在焊缝和部件上来回扫描，操作者通过屏幕观察缺陷。主要的不同之处在于观察者也可以看见S-扫描（参见图1和图3示例）或者E-扫描，这些扫描可以辅助缺陷分析。总之，尽管屏幕显示可以存储和报告，数据并不被采集。一些手动设备可以使用时基数据采集来收集扫描数据；然而，跟编码数据相比这种数据本质上是不可靠的，因为所测量的缺陷长度将会取决于操作者的扫描速度，且其长度无法校准。时基扫描，或者波束扫描，尤其不能被诸如美国工程师协会规范案例2235（2）之类的自动超声波测试规范所接受。为什么购买波束扫描设备?以下是几种可能的原因。如果这设备能每次展现多重A-扫描（如美国焊接协会D1:1检查标准的45,60和70o-参见参考文献3),那么潜在地,操作者可以扫描得更快.(当然,此设备标准必须符合美国工程师协会或者其他规范。)如上所提，在某些情况下2D成像可以提高缺陷评估和数据存储水平。对于一些应用领域诸如氢致裂纹，一套波束扫描设备可能足够了。而且花费也比较低。波束扫描设备实际上所不能做的就是储存完整数据，同时地执行多重功能和进行线性扫描。以下均会涉及到。很多不同的制造商都有波束扫描设备，图1显示的是一个典型的手动相控阵列设备。图1：商用波束扫描（或手动）相控阵列设备：Olympus 无损检测 全方位扫描M（“手动”相控阵列版）。注意其他制造商也生产波束扫描设备。编码相控阵列设备编码相控阵列设备能用编码器收集和储存扫描数据，并探测位置数据。虽然这听上去没什么大不了-毕竟，往电子设备上添加一个编码器理论上并不难-真正的重点在于其软件。编码相控阵列设备可以收集完整的A-扫描波形数据，存储和处理显示，以提供“顶部，侧边，底部”视图，并处理此数据。换句话说，编码相控阵列设备是便携式的，花费低的AUT（自动超声波测试）系统，而波束扫描相控阵列设备是重要的单晶体设备。扫描的数据可以在线下数据分析中重复播放。编码相控阵列设备为焊缝等部件提供主要的时间和成本优势。图2a展示了传统的光栅检测过程，用探测器向着焊缝来回移动。另一方面，图2b展示了利用“线性扫描”进行的焊缝检测，例如，在列阵进行光栅扫描时用单程平行扫描焊缝进行检测。波束扫描相控阵列设备进行光栅扫描（图2a），而编码相控阵列设备也能进行线性扫描（图2b）。图2a（左），常规光栅扫描。图2b(右)线性扫描。线性扫描在速度方面提供了重要优势，或许比单晶体检测速度高达5至10倍。除了采集和显示所有的缺陷，一些编码相控阵列设备能同时进行多方位扫描，例如，它们能在一个单程扫描中完成编码要求，此过程需要阵列在焊缝任意一侧进行（参见图3).更先进的设备还能够进行诸如衍射时差法超声检测之类的额外扫描。图3：来自编码扫描全方位扫描MX的多组屏幕显示. 注意其他制造商也生产编码便携式相控阵列设备。自然，带有编码器性能，数据存储，显示器（影像）再现，更多频道和某些信号处理功能，这样的编码相控阵列设备相对于波束扫描相控阵列设备更昂贵。编码相控阵列设备使用者需要更多培训。然而，对于正确合适的应用领域来说，编码数据收集是一个更好更有效的解决方案，而且在大多数情况下也是唯一的相控阵列解决方案（参加以下样本应用）。图3 列举了一个编码相控阵列设备的案例。相控阵列规范兼容性尽管相控阵列技术还很新颖，但巨大的市场需求要求相控阵列能与各种各样的规范兼容。幸运的是，大多数主流美国规范诸如美国工程师协会（4）和美国焊接协会(3)本身就将相控阵列看做一门技术，但是需要证明被提及的此技术和程序符合规范。此证明可以通过多种途径进行，例如，美国工程师协会第五章第十四条款(5),或者通过美国工程师协会规范案例2235(2).检查编码数据是否符合美国工程师协会规范案例2235要求是非常重要的。当前，可以说美国工程师协会是编纂相控阵列技术规范的领头羊。规范案例2541早已付梓(6),其他规范还在编纂中。相控阵列一个值得注意的特征就是即将到来的校准要求。美国工程师协会把S-扫描和E扫描解释为多重波形，每一种都需要校准符合规范。美国工程师协会关于创建相控阵列的新标准惯例采取了同样的方法：要求全角度校准增益 (ACG)和时间校准增益(TCG)。样本应用波束扫描相控阵列设备对需要手动操作和成像的应用领域大有裨益，典型的是一些工作状态中的应用。这里，要求的裂缝尺寸或者缺陷表征，和应力腐蚀裂纹或者氢致裂纹一样。很明显，好的数据分析性能和一些成像存储是有益处的，但大多数波束扫描设备能满足这些最小要求。其他应用领域诸如螺栓可以用波束扫描设备进行检测，但用机械化和编码扫描能更好的检测。如果设备能被准确地校准，焊缝的检测可以使用波束扫描，但不如编码扫描速度快，而且数据也不能存储。航空航天应用领域的检测视具体情况而定。编码相控阵列设备对任何需要重复和存储数据的检测来说都是很有益处的。这包括了代码类型焊缝检测，制造，锈蚀测绘，高速检测，远程应用和精准检测(1)；基本上任何目前自动超声波测试所记载的应用领域。波束扫描设备还是编码相控阵列设备？答案取决于应用领域。对于一些有限的应用，波束扫描设备可能就足够了，但是购买者需要确认此设备能满足任何规范。对于更先进的应用，更好的灵活性要求，很明显编码相控阵列设备是很好的选择。一个可行的方案就是购置一台能升级的设备，因此操作者可以根据需要从波束扫描升级到编码扫描，或者新手操作者想提升自己的发展水平。参考文献1. R/D科技，相控阵列超声波科技应用简介-R/D科技参考，出版公司R/D科技 责任有限公司，2004.1. 美国工程师协会 锅炉和压力容器规范，规范案例2235-9,2005年10月11日, 应用超声波检测代替放射线照相术。3. 美国焊接协会，AWS D1.1，结构焊接规范，2006.4. 美国工程师协会第五章第四款，美国工程师协会 锅炉和压力容器规范， 2001,2003修订版，美国工程师协会，纽约。5. R.G.Ginzel, E.A.Ginzel, J. Mark Davis, S. Labb and M.D.C.Moles， 美国工程师协会第五章便携式相控阵列合格证书，2006年美国工程师协 会压力容器和管道大会会议记录，7月23-27日，2006年；加拿大，哥伦比 亚省，温哥华，PVP2006-ICPVT11-93566。6. 美国工程师协会 锅炉和压力容器规范，规范案例2541,2006年1月19日， 第五章使用手动相控阵列检测。7. 美国工程师协会，评价相控阵列超声波检测仪器和系统性能特征标准参考， E-2491-06， 美国测试和材料协会，2006年6月。翻译原文Phased Arrays vs. Phased Arrays-Beam Sweeping vs. Encoded Data CollectionJ. Mark Davis1 and Michael Moles22Olympus NDT Canada, Toronto, ON, Canada, Tel: (416) 8314428, eFax: (905) 248-3546, Email: M, Web site: 1J. Mark Davis, Davis NDE, Inc., Birmingham, AL, USA, Tel: (205) 733-0404, Email: , Web site: Abstract This article describes the differences between manual and encoded phased array units. While merely adding an encoder may not seem technically demanding, the software requirements and improved capabilities are significant. Many NDT applications cannot be performed by manual (or “beam sweeping”) PA units due to code or technical limitations.IntroductionPhased arrays are one of the hot technologies in NDT at this time, with good reason. Compared with conventional ultrasonics, phased arrays offer significant advantages: l Speed; for welds, corrosion and other components, linear (or line scanning) scanning can increase scanning speed (and hence reduce costs) significantly. l Imaging; S-scans, E-scans and other 2D and 3D imaging can give much better and more interpretable defect assessments. l Flexibility; phased arrays can perform a wide variety of scans, for a wide variety of defects on many different types of components (1). l Data storage; full or even partial data storage and display allows better defect interpretation, plus can be used for archive purposes. l Reproducibility; though not demonstrated yet by third party trials, using the same set-up and procedure with phased arrays gives much more reproducible results than with manual ultrasonics.However, there is more than one type of phased array instrument available on the market. Besides the large, non-portable units which have been available for a decade, there are portable units available from several manufacturers. The portable units themselves can be divided into two categories: manual and encoded, and the differences and capabilities are significant. This article describes the various features and capabilities, plus mentions some of the different types of applications that can be performed with manual and encoded units. Phased arrays are quite well referenced in the literature, so this paper will not describe them. For a broad assessment of the physics, hardware, software and sample applications, see (1).The beam sweeping units, i.e. the manual units, operate like upscale monocrystal units that can also sweep the beam. These units use a manually-held array in much the same manner as a manual probe, i.e. the array is rastered toward and away from the weld or component, and the operator watches the screen for defects. The main difference is that the operator also sees an S-scan (see Figures 1 and3 for examples) or E-scan, which can assist in defect analysis. In general, data is not collected, though screen displays can be saved and reported. In some manual units, it is possible to collect scans using time-based data collection; however, this data is inherently unreliable compared with encoded data since the measured defect length will depend on the operators scanning speed, and the lengths are not calibrated. Time-based scanning, or beam sweeping, is specifically not acceptable for AUT codes such as ASME Code Case 2235 (2).Why buy a beam sweeping unit? There are several possible reasons. If the unit can display multiple A-scans at one time (e.g. 45, 60 and 70for AWS D1:1 inspections see ref 3), then potentially the operator can scan faster. (Of course, the unit must be calibrated to the meet the ASME or other Code.) As mentioned above, under some circumstances 2D images can improve defect assessment and data storage. For some applications, e.g. Hydrogen Induced Cracking, a beam sweeping unit maybe adequate. And the cost is lower. What beam sweeping units cannot realistically do is store full data, perform multiple functions simultaneously, and perform linear scanning. These are covered below. Beam sweeping units are available from various manufacturers, and Figure 1 shows a typical manual PA unit.Figure 1: Commercial beam sweeping (or manual) PA unit: Olympus NDTs OmniScan M (the “manual” PA version). Note that other manufacturers also produce beam sweeping units.Encoded PA Units Encoded phased array units have the capability of using an encoder for collecting and storing scan data and probe position data. While this may not sound like a big difference after all, adding an encoder to an electronic unit is theoretically not a big deal the real story is in the software. Encoded PA units can collect full A-scan waveform data, store and manipulate displays to give “top, side, end” views and process this data. In other words, encoded PA units are a portable, low cost AUT (Automated Ultrasonic Testing) system, whereas beam sweeping PA units are glorified monocrystal units. Scanned data can be replayed for offline data analysis.Encoded PA units offer major time and cost advantages for components like welds. Figure 2a shows the traditional raster inspection process, with the probe being moved back and forth towards the weld. Figure 2b, on the other hand, shows weld inspections using “linear scanning”, i.e. inspecting using a single pass parallel to the weld while the array performs the rastering. Beam sweeping PA units perform raster scanning (Figure 2a), while encoded PA units can perform linear scanning (Figure 2b) as well.Figure 2a (left), conventional raster scanning. Figure 2b (right) linear scanning.Linear scanning offers significant advantages in speed, maybe up to a factor of five or ten times over monocrystal inspections. Besides collecting and displaying all the defects, some encoded PA units can perform multiple scans simultaneously, i.e. they can fulfill the code requirements in a single pass, with arrayson either side of the weld (see Figure 3). The more advanced units can also perform additional scans like TOFD.Figure 3: Multigroup screen display from OmniScan MX for encoded scanning. Note that other manufacturers also produce encoded portable phased array units.Naturally, with encoder capability, data storage, display reconstruction, more channels and some signal processing, the encoded PA units are more expensive than the beam sweeping PA units. They also require more training. However, for the correct applications, encoded data collection is a much better, more cost-effective solution, and in many cases is the only PA solution (see Sample Applications below). Figure 3 shows an example of an encoded PA unit.PA Code Compatibility Though phased arrays are new, there is a big push from the marketplace to get phased arrays accepted by the various codes. Fortunately, most of the major US codes like ASME (4) and AWS (3) inherently accept phased arrays as a technology, but require demonstration that the proposed technique and procedure fulfill the code. This can be performed through various routes, e.g. ASME Section V Article 14 (5), or through ASME Code Case 2235 (2). It is important to check if encoded data is required, as with ASME CC 2235. At this time, ASME is arguably the leader in codifying phased arrays. Code Case 2541 is already in print (6), and other code cases are in progress. One notable feature for phased arrays are the upcoming calibration requirements. ASME has interpreted an S-scan or an E-scan as multiple waveforms, each of which must be calibrated to Code. The new ASTM standard practice for setting up phased arrays (7) has taken the same approach: full Angle Corrected Gain (ACG) and Time Corrected Gain (TCG) are required.Sample Applications Beam sweeping PA units are good for applications which require manual manipulation and imaging, typically some in-service applications. Here, crack sizing or defect characterization is required, as with stress corrosion cracking or Hydrogen Induced Cracking. Obviously, good data analysis capability and some image storage are beneficial, but most beam sweeping units can fulfill these minimal requirements. Other applications, like bolts, can be performed by beam sweeping units, but these are best performed using mechanized and encoded scanning. Welds can be inspected using beam sweeping, provided the unit can be correctly calibrated, but will not be as fast as encoded scanning, nor will the data be stored. Aerospace applications will depend on the specifics. Encoded PA units will be beneficial for any inspection that requires reproducible, stored data. This includes code-type weld inspections, manufacturing, corrosion mapping, high speed inspections, remote applications, and precision inspections (1); essentially any application that is currently filled by AUT. Beam Sweeping or Encoded PA Units? The answer depends on the applications. For some limited applications, a beam sweeping unit may be adequate, but the purchaser should make sure that t