摘要
利用超声衍射时差法(TOFD)对厚壁管道实施周向扫查时,曲率表面与直通波路径不重合,引起倾斜裂纹长度和角度定量误差。为实现深层裂纹检测,提高探头中心距(PCS)进一步增加检测误差。考虑管道外壁曲率半径、PCS与裂纹端点深度之间的几何关系,开展厚壁管道倾斜裂纹精准定量研究。推导厚壁管道TOFD检测周向扫查时,裂纹长度和倾斜角度定量公式,并对比优化前后检测误差。仿真研究表明,对壁厚30.0 mm,外壁曲率半径148.0 mm的碳钢管道内,长度4.0 mm,倾斜角度10°~50°的裂纹实施检测时,长度和倾斜角度定量误差分别下降可达0.10 mm和1.58°。实验针对碳钢管道试块中长度4.0 mm,倾斜角度30°的裂纹,长度和倾斜角度定量误差从0.30 mm和2.74°,降低至0.27 mm和0.28°。所述方法可适用于不同曲率管道内部倾斜裂纹定量检测,应用范围较广。
When the circumferential scanning for thick-walled pipe is carried out with ultrasonic time of flight diffraction(TOFD), the ray path of lateral wave is inconsistent with the curved surface, which leads to the quantitative errors of length and angle for inclined cracks. To achieve deep crack detection, the probe center spacing(PCS) may be increased, which further increases the measurement errors. In this paper, considering the geometrical relationship among the curvature radius of pipe outer wall, PCS and crack tip depth, the accurate quantification study of the inclined cracks in thick-walled pipes is conducted. The quantitative formulas for the crack length and inclined angle are deduced for the detection of thick-walled pipes with circumferential scanning of TOFD, and the measurement errors before and after optimization are compared. The simulation results show that the quantitative errors of crack length and inclined angle are reduced by 0.10 mm and 1.58°, respectively for the crack with crack length of 4.0 mm and inclined angle of 10°~50° in the carbon steel pipe with wall thickness of 30.0 mm and curvature radius of outer wall of 148.0 mm. Experiment on a carbon steel pipe specimen was conducted. In the experiment, the quantitative errors of crack length and inclined angle are reduced from 0.30 mm and 2.74° down to 0.27 mm and 0.28°, respectively for the crack with crack length of 4.0 mm and inclined angle of 30°. The proposed method is suitable for the quantitative detection of inclined cracks in pipes with different curvature radii, and has wide application fields.
引文
[1] 代真,王昕,敬尚前,等.核电厚壁承压容器内壁缺陷TOFD检测优化研究[J].核动力工程,2014,35(2):79- 83.DAI ZH,WANG X,JING SH Q,et al.Optimization of TOFD detection for inner wall defects of nuclear power thick wall pressure vessels[J].Nuclear Power Engineering,2014,35(2):79- 83.
[2] 李东升,王昌明,施祖康,等.管道壁缺陷超声波在役检测的量化分析研究[J].仪器仪表学报,2002,23(2):131-134.LI D SH,WANG CH M,SHI Z K,et al.Research on quantification of wall-loss defects for on-line pipeline inspection with ultrasonic method[J].Chinese Journal of Scientific Instrument,2002,23(2):131-134.
[3] CARVALHO A A,REBELLO J M A,SOUZA M P V,et al.Reliability of non-destructive test techniques in the inspection of pipelines used in the oil industry[J].International Journal of Pressure Vessels & Piping,2008,85(11):745-751.
[4] 詹湘琳,陈世利,张宇,等.超声相控阵在管道缺陷检测中的优化设计[J].仪器仪表学报,2006,27(增刊2):1581-1582.ZHAN X L,CHEN SH L,ZHANG Y,et al.Optimum design of ultrasonic phased array in flaw detection of pipeline[J].Chinese Journal of Scientific Instrument,2006,27(Suppl.2):1581-1582.
[5] 丁宁,金士杰,张东辉,等.基于波型转换的TOFD近表面盲区抑制研究[J].机械工程学报,2017,53(16):120-124.DING N,JIN SH J,ZHANG D H,et al.Research on near surface dead zone reduction of TOFD based on mode-converted theory[J].Journal of Mechanical Engineering,2017,53(16):120-124.
[6] MANJULA K,VIJAYAREKHA K,VENKATRAMAN B.Quality enhancement of ultrasonic TOFD signals from carbon steel weld pad with notches[J].Ultrasonics,2017(84):264- 271.
[7] 陈建,孙晓颖,林琳,等.基于单周期互相关滤波的超声波TOF检测方法[J].仪器仪表学报,2014,35(3):664- 669.CHEN J,SUN X Y,LIN L,et al.Accurate ultrasonic TOF measurement method based on monocycle cross-cor-relation filtering[J].Chinese Journal of Scientific Instrument,2014,35(3):664- 669.
[8] DARMON M,CHATILLON S,MAHAUT S,et al.Simulation of Disoriented Flaws in a Tofd Technique Configuration Using Gtd Approach[J].Nondestructive Evaluation,2008,975(1):155-162.
[9] 谢雪,祝美丽,杨会敏,等.合成孔径聚焦技术在超声衍射时差法缺陷长度定量中的应用研究[J].机械工程学报,2015,51(18):20- 25.XIE X,ZHU M L,YANG H M,et al.Research of synthetic aperture focusing technology in the application of crack length sizing by time of flight diffraction techinique[J].Journal of Mechanical Engineering,2015,51(18):20- 25.
[10] 王国庆,杨理践,刘斌,等.基于磁记忆的油气管道应力损伤检测方法研究[J].仪器仪表学报,2017,38(2):271- 278.WANG G Q,YANG L J,LIU B,et al.Study on the testing method of oil-gas pipeline stress damage based on magnetic memory[J].Chinese Journal of Scientific Instrument,2017,38(2):271- 278.
[11] 刘金海,臧东,汪刚.基于Markov特征的油气管道泄漏检测与定位方法[J].仪器仪表学报,2017,38(4):944-951LIU J H,ZANG D,WANG G.Leakage detection and location method of oil and gas pipelines based on Markov features[J].Chinese Journal of Scientific Instrument,2017,38(4):944-951.
[12] FERRAND A,DARMON M,CHATILLON S,et al.Modeling of ray paths of head waves on irregular interfaces in TOFD inspection for NDE[J].Ultrasonics,2014,54(7):1851-1860.
[13] NATH S K,BALASUBRAMANIAM K,KRISHNAMURTHY C V,et al.Sizing of surface-breaking cracks in complex geometry components by ultrasonic time of flight diffraction (TOFD) technique[J].Insight Non Destructive Testing and Condition Monitoring,2007,49(4):200- 206.
[14] 康宝杰,惠兆祥.圆筒面纵向焊缝TOFD检测缺陷定位[J].无损检测,2015,37(4):60- 65,68.KANG B J,HUI ZH X.Flaw localization of the cylinder surface longitudinal weld by TOFD examination[J].Nondestructive Testing,2015,37(4):60- 65,68.
[15] 马有理.倾斜裂纹的应力分布与裂纹面开口位移的关系[J].浙江大学学报(工学版),2009,43(8):1443-1447.MA Y L.Relationship between stress distribution along slant crack and opening displacement on crack-surface[J].Journal of Zhejiang University,2009,43(8):1443-1447.
[16] 迟大钊,刚铁,盛朝阳.超声渡越时差法检测图像中裂纹端部信号的识别[J].机械工程学报,2007,43(10):103-107.CHI D ZH,GANG T,SHENG ZH Y.Method forcrack tip recognition in an ultrasonic time of flightdiffraction image[J].Chinese Journal of Mechanical Engineering,2007,43(10):103-107.
[17] HAN Q,WANG P,ZHENG H.Modified ultrasonic time-of-flight diffraction testing with Barker code excitation for sizing inclined crack[J].Applied Acoustics,2018(140):153-159.
[18] 陈婷婷.基于超声TOFD-LWE检测方法的缺陷识别与研究[D].哈尔滨:哈尔滨工程大学,2011.CHEN T T.Defect Recognition and Research Based on Ultrasonic TOFD-LWE Detection Method[D].Harbin:Harbin University of Science and Technology,2011.
[19] 孙旭,金士杰,张东辉,等.基于自回归谱外推方法的TOFD检测盲区抑制[J].机械工程学报,2018,54(22):15-20.SUN X,JIN SH J,ZHANG D H,et al.Suppression of dead zone in TOFD with autoregressive spectral extrapolation[J].Journal of Mechanical Engineering,2018,54(22):15-20.
[20] 张树潇.厚壁压力容器TOFD检测参数优化与缺陷定量研究[D].大连:大连理工大学,2014.ZHANG SH X.The parameter optimization flaw sizing TOFD testing thick-walled pressure vessel[D].Dalian:Dalian University of Technology,2014.
[21] GANG T,SHENG Z Y,TIAN W L.Time resolution improvement of ultrasonic TOFD testing by pulse compression technique[J].Destructive Testing and Condition Monitoring,2012,54(4):193-197.
[22] 康达,陈尧,金士杰,等.基于相位相干成像的TOFD检测缺陷图像增强处理研究[J].压力容器,2016,33(6):59-66.KANG D,CHEN Y,JIN SH J,et al.Enhancement of defect image in ultrasonic TOFD detection based on phase coherence imaging[J].Pressure Vessel Technology,2016,33(6):59-66.