Experimental study of the surface notches detection on cylinder bymeans of scanning laser line source
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摘要: 为了研究瑞利波与圆柱表面缺陷的相互作用,并以此作为检测圆柱表面缺陷的理论依据,设计了一套实验装置,该装置采用脉冲激光线源产生超声波,激光干涉仪探测瑞利波信号,通过改变激发源与人工缺陷的相互位置研究了瑞利波与缺陷的相互作用过程。实验中在不同的相互位置得出了不同的瑞利波波形,反射瑞利波的峰-峰值随激光源与缺陷的距离减小而增大,且当激发点位于缺陷边缘处时波形的极性改变。结果表明,当应用本装置时,通过改变人工缺陷与激光光源相对位置,再利用检测峰-峰值的极大值情况和根据接收到的瑞利波的极性可以判断缺陷的位置。Abstract: In order to investigate interaction between Rayleigh waves and the notches on the surface of a cylinder, an experiment setup was designed.By changing the relative position between generation source and the notch, Rayleigh waves were detected by a laser interferometer with applying a pulse laser to generate the signal.Experimental results demonstrated that different Rayleigh waves were obtained at different positions, that peak-to-peak value of reflective Rayleigh waves increased with the decrease of laser source-notch distance, and that the waves'polarity transformed.Therefore, detecting the maximum of peakpeak value can be utilized to judge the position of the notch by rotating the sample while keeping the position of generation source unchanged; the polarity can also be used in further judgments.
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Keywords:
- laser technique /
- notch detection /
- scanning laser line source /
- Rayleigh wave
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[1] YUAN Y Q,CHEN S Z.Principles and applications of ultrasonic in modern times[M].Nanjing:Nanjing University Press,1996:323(in Chinese).
[2] CLORENNEC D,ROYER D.Analysis of surface acoustic wave propagntion on a cylinder using laser ultrasonics[J].A P L,2003,82 (25):4608-4610.
[3] JIAN X,DIXON S,GUO N,et al.Rayleigh wave interaction with surface-breaking cracks[J].J A P,2007,101(6):064906/1-064906/7.
[4] GAO W,GLOBIEUX C.THOEN J.Study ofcircumferential waves and their interaction with defects on cylindrical shells using line-flource laser ultrasonics[J].J A P,2002,91(9):6114-6119.
[5] KROMINE A K,FOMITCHOV P A,KRISHNASWAMY S,et al.Laser ultrasonic detection of surface-breaking discontinuities:scanning laser source technique[J].Materials Evaluation,2000,58(2):173-177.
[6] KROMINE A K,FOMITCHOV P A,KRISHNASWAMY S,et al.Detection of subsurface defects using laser based technique[J].Review of Progress in Quantitative Nondestructive Evaluation,2001,20:1612-1617.
[7] GUAN J F,SHEN Zh H,XU B Q.Spectral analysis of the scattering waveform of the laser-generated ultrasonic waves for detecting the crack in the material[J].Laser Technology,2005,29(3):287-290(in Chinese).
[8] GUAN J F,SHEN Zh H,LU J,et al.Finite element analysis of the scanning laser line aource technique[J].Japan J A P,2006,45 (6A):5046-5050.
[9] SHI Y F,SHEN Zh H,NI X W,et al.Finite element modeling of asoustic field induced by laser line source near sudface defect[J].Optics Express,2007,15(9):5512-5520.
[10] XU B Q,SHEN Zh H,NI X W,et al.Finite element modeling of alser-generated ultrasound in coating-substmte system[J].J A P,2004,95(4):2109-2115.
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