摘要
随着焊接技术的飞速发展,焊接结构越来越多的应用于现代工业的连接和密封,焊接接头的可靠性将直接影响整体结构的质量和安全。由于焊接接头往往承受高温,高压或者兼有腐蚀的严酷环境,因此很可能在服役期内便发生应力集中甚至失效断裂。为了避免灾难的发生,世界各国都非常重视对大型结构件进行无损检测和在役焊缝的寿命评估。由于现场检测时仍然存在着:检测数据难以存储,容易发生漏检,缺陷定位困难和检测结果因人而异等问题。因此,开发出一套能够克服以上困难的便携式数字化超声检测系统成为了科研人员的研究热点和难题。
本文以解决上述实际工程问题为出发点,开发一套超声波检测系统。此系统通过USB接口与移动电脑互联实施现场检测,这大大的扩展了其使用范围。从结构上,本系统分为超声波信号采集和超声波换能器定位传感两部分;从功能上,本系统通过调用接口函数将采集到的超声波信号和探头位置信号有机结合起来,不仅能够在检测过程中实时显示超声探头的行走路径,而且可以自动生成缺陷俯视图和侧视图。这些功能较好的解决了检测中缺陷信息的获取问题,并且实现了直观的缺陷的定位和形貌描述。此外数字化存储功能为数据的后续处理和焊缝的寿命评估提供了可靠的依据。
为了验证系统精度和实际应用价值,利用组建起的超声检测系统分别对人工缺陷和实际焊缝进行了扫查。人工缺陷检测结果表明系统精度满足检测要求;分析对比了实际焊缝缺陷的X射线检测图像、超声衍射时差及本系统检测的图像,表明本研究的检测系统能够实现缺陷的检测与定位,并能在一定程度上弥补射线法和TOFD法的不足,具有很好的实际应用价值。
With the development of welding technology, welded structure is being widely used in connection and seal situation of modern industry. The quality of holistic structure depends on the reliability of welded seam. Usually welded seam bears high temperature, high press and even corrodent environment; therefore it might stress concentration or even collapsing during attended time. In order to avoid disaster happens, developed countries pay much attention to proceed NDT to large-scale structure and longevity evaluation of in-service welded beam. Unfortunately many problems still exist during field detection: save defect data; undetected; defect allocation and so on.
To solve these problems, this article will develop an ultrasonic detect and defect allocation system. This system can proceed field detection when connected with a note-book through USB interface, this pattern extend the applicability. And it is composed by two parts. One is ultrasonic signal collection device; another part is ultrasonic probe allocation transducer device. The function of this system as follows: display the motion route of the probe in real-time; generate the top view and side view of the defect automatically. These functions solve the problem that how to obtain the defect information during detection very well; further more the two views realize defect allocation and pattern description. Data saving provide a reliable foundation for data manipulation and welded beam lifetime evaluation later.
To certificate the precision and application value, we scan artificial defect and real welded beam respectively by using the ultrasonic defect system we developed. The result of artificial defect scan shows that the precision of the system meet detect request. By scanning a real welded beam and comparing X-Ray image, TOFD view and defect view given by our detect system, this detect system represent high theory significance. In a word, the portable type digital ultrasonic defect system this article developed implements defect detection and defect allocation.
引文
1李生田,刘志远.焊接结构现代无损检测技术.机械工业出版社, 2000, 46(5):1~85
2 Bevan Bfaithwaite. Collaboration between TWI and CWI. JOM. 2007, 44(7):15~23
3赵熹华.焊接检验.机械工业出版社. 1992:1~2
4 N. Nielsen. P-scan system for ultrasonic weld inspection. British Journal of Non-Destructive Testing, 1981, 23(2):63~69
5 G. A. Georgiou, M. Blackmore, R. K. Chapman, et al. The application of geometrical theory of diffraction to modeling pulsed ultrasonic inspection: a system model. British Journal of Non-Destructive Testing. 2004, 31:551~561
6 M. Dubresson, M. Chauveaux. Application of mechanical scanning systems to the ultrasonic inspection of welds. Ultrasonic Imagine For Weld Inspection. 2005, 49(8):15~23
7 ASNT. Directory of educational institutions offering courses in nondestructive testing. Materials Evaluation. 2008, 5(3):288~296
8 G.M. Van, J. Boogaard. NDT reliability a way to go. Proceeding 13th World Conference NDT. 1992:95~98
9 J.W. Probabilistic fracture mechanics and reliability. Matinus Nijhoft Publishers. Dordrecht, 2005:39~42
10 M. F. Kanninen, C. H. Popelar. Advanced fracture mechanics. Oxford University Press, 2001:9~10
11张家骏.无损检测技术的发展及其对国民经济发展的影响.无损检测. 2003, 15(2):31~35
12张立权,李平瑾,王兵等.压力容器的焊接和无损检测技术进展.中国锅炉压力容器安全. 2007, 14 (2):11~17
13袁易全,陈思中.近代超声原理与应用.南京大学出版社, 2006: 440~462
14金长善.超声工程.哈尔滨工业大学出版社, 1999:105~125
15蒋危平,王务同.超声波探伤仪发展简史.无损检测. 2002, 19(1):24~25
16何凤歧.第13届世界无损检测会议仪器展览见闻.无损检测. 2003, 15(4):115~116
17郭成彬.智能超声探伤仪的现状和前景.无损检测. 1991, 13(1):1~4
18 J. Ronald Botsko, Yasunobu Horiguchi. Digital ultrasonic non-destructive testing in the United States. Journal of JSNDT, 1996, 45(9):649~656.
19徐永昌,郭成彬.第14届世界无损检测会议概况.无损检测. 1997, 19(2):31~ 44
20吴明复.焊缝的无损检测技术.航天工艺. 2001, 10(6):50~53
21 A. David Stubbs, P. Larry Zawada. Detection of porosity in glass ceramic matrix composites using an ultrasonic multiple-gate C-scan technique. Materials Evaluation, 1996, 54(7):827~831
22王裕文,刘大文,侯成刚等. JTUIS系列超声成像检测系统.航天工艺. 2000, 2: 53~55
23 W. P. Motzer. Ultrasonic B-scan system used to inspect composite airplane parts. WCNDT. 1996, 14: 2099~2102
24沈建中.超声成像技术及其在无损检测中的应用.无损检测. 2004, 16(7):202~206
25 N. Neilson. P-scan system for ultrasonic weld inspection. British Journal of DNT. 2001, 5:63~69
26郑中兴.便携式超声波P扫描成像系统软件的设计.无损检测. 1996, 18(12):333~336
27 R. J. Liou, K. C. Kao, C. Y. Yeh, et al. Flaw detection and sizing of ultrasonic images using wavelet transform and SAFT. Proceedings of 2004 International Symposium on Intelligent Signal Processing and Communication Systems. 2004:106~110
28 E. Biagi, L. Masotti, I. Rossi, et al. Synthetic aperture technique for echo graphic focusing based on pulse compression. IEEE Ultrasonic Symposium, 2004:1425~1427
29 K. C. Oliver, H. Christian, K. Patrick, et al. Ultrasonic imaging of sheet metal forming. Ultrasonic. 2004, 42(1-9):989~992
30 S. Martin, J. Winifred. Synthetic aperture focusing for defect reconstruction inanisotropic media. Ultrasonic. 2003, 41(2):125~131
31孙宝申,张凡,张建中.合成孔径聚焦成像时域算法研究.声学学报. 1997, 22(1):42~49
32 M P Hayes, P T Gough. Broad-band synthetic aperture sonar, IEEE Jour. Of Oceanic Engineering. 2007, 17(l):80~94
33黄剑哲,兰从庆,刘政林等.数字聚焦超声反射CT成像初步研究.声学技术. 1998, 17(4):159~162
34 Ning Zhu, Rong Qiu, Seizo Kato. Ultrasonic CT measurement of temperature inside a vessel. Fire Safety Science. 2002, 11(1):24~31
35 A. A. Carvalho, J. M. A. Rebello, R. R. Silva, et al. Reliability of the manual and automatic ultrasonic technique in the detection of pipe weld defects. Insight: Non-Destructive Testing and Condition Monitoring, 2006, 48(11):649~654
36 S. Baby, T. Balasubramanian, R. J. Pardikar, et al. Time-of-flight diffraction (TOFD) technique for accurate sizing of surface-breaking cracks. Insight: Non- Destructive Testing and Condition Monitoring, 2003, 45(6):426~430
37 Y. Murai, K. Saito, N. Suzuki, et al. Ultrasonic testing of welded joint models for bridge construction based on the TOFD method. Research and Development Kobe Steel Engineering Reports, 1999, 49(2):45~47
38 F. H. Dijkstra, J. A. Raad, T. Bouma. Time of flight diffraction and acceptance criteria: A perfect team. Materials Evaluation, 1998, 56(3):395~398
39 J. William, A. José, A. Glenn. Crack Measurement in Steel Plates Using TOFD Method. Journal of Performance of Constructed Facilities, 2000, 14(2):75~82
40 J. Verkooijen. TOFD used to replace radiography. Insight: Non-Destructive Testing and Condition Monitoring, 1995, 37(6):433~435
41 J. Harry, W. Jan, G. Paul, et al. Improved plant availability by advanced condition based inspections. Pressure vessels and piping, 2004, 81:491~497
42 J. William. Crack measurement in steel plates using TOFD method. Journal of Performance of Constructed Facilities. 2000, 14(2):75~82
43 M. Barry. M. Yarmuch, F. Corp. Novel High Resolution Defect Detection for Thermoplastic Butt-welds. Pipeline and Gas Journal. 2003, (3):7~33
44 Lawrence Azar, Shi-Chang Wooh. Experimental characterization of ultrasonicphased arrays for the nondestructive evaluation of concrete structures. Materials Evaluation. 1999, 57(2):134~140
45 Jessica Green. Materials Evaluation. Pipeline and Gas Journal. 2007, 55(2): 26~28
46 Steve Mahau.用动态自适应超声聚焦系统确定缺陷特性,无损检测, 1998, 20(8) :236~238
47 T. Ikeda, H. Karasawa, S. Satonaka, et al. Development of new ultrasonic inspection technique for spot welds with matrix arrayed probe and saft. Welding in the World. 2006, 50(5-6):3~13