Numerical study on improvement of signal-to-noise ratio of surface acoustic waves based on laser array
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1.
Jincheng College, Nanjing University of Science and Technology, Nanjing 211156, China;
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2.
Ordnance Test, Nanjing University of Science and Technology, Nanjing 210094, China;
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3.
College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
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Received Date:
2010-10-16
Accepted Date:
2010-11-24
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Abstract
In order to improve the signal-to-noise ratio (SNR) of surface acoustic waves (SAWs) in laser ultrasonic test, laser array, obtained by the temporal and spatial modulation of the line sources, was used to irradiate on the aluminum plate, and the physical processes, including the generation of SAWs (giant SAWs) with huge displacement amplitude and the interactions between the giant SAWs and the surface breaking crack were simulated by means of the finite element method. The numerical results demonstrate that the displacement amplitude of the giant SAWs generated by the laser array increases in proportion with the number of laser array elements. Besides, the amplitude of the reflected SAWs, generated by the interactions between the giant SAWs and the surface breaking crack, is also increased as the numbers of the line sources increased. The results can provide some hints for the utilization of the thermoelastic laser array to improve SNR of the SAWs.
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References
|
[1]
|
WAGNER J W,DEATON J B,MCKIE A D W,et al.Laser ultrasonics:generation and detection considerations for improved signal-to-noise ratio[J].Proceedings of SPIE,1990,1332:491-501. |
|
[2]
|
STECKENRIDER J S,MURRAY T W,WAGNER J W,et al.Sensitivity enhancement in laser ultrasonics using a versatile laser array system[J].Journal of the Acoustical Society of America,1995,97(1):273-279. |
|
[3]
|
CHENU C,NOROY M H,ROYER D.Giant surface waves generated by a multiple beam laser:application to the detection of surface breaking slots[J].Applied Physics Letters,1994,65(9):1091-1093. |
|
[4]
|
LIU Y H,WU T T,LEE C K.Application of narrow band laser ultrasonics to the nondestructive evaluation of thin bonding layers[J].Journal of the Acoustical Society of America,2002,111(6):2638-2643. |
|
[5]
|
NOROY M H,ROYER D,FINK M.Transient elastic wave generation by an array of thermoelastic sources[J].Applied Physics Letters，1993,63(24):3276-3278. |
|
[6]
|
YANG J,UME C.Performance evaluation of fiber array for NDE application[J].Research in Nondestructive Evaluation,1994,5(3):175-190. |
|
[7]
|
MURRAY T W,BALDWIN K C,WAGNER J W.Laser ultrasonic chirp source for low damage and high detectability without loss of temporal resolution[J].Journal of the Acoustical Society of America,1997,102(5):2742-2746. |
|
[8]
|
WANG H Ch,FLEMING S,LEE Y Ch.Simple,all-optical,noncontact,depth-selective,narrowband surface acoustic wave measurement system for evaluating the Rayleigh velocity of small samples or areas[J].Applied Optics,2009,48(8):1444-1451. |
|
[9]
|
WAGNER J W,DEATON J B,SPICER J B,et al.Laser generation of narrowband and directed ultrasound for noncontact ultrasonic testing [J].Ultrasonics Symposium,1990,2:661-665. |
|
[10]
|
HUANG J,KRISHNASWAMY S,ACHENBACH J D.Laser generation of narrow-band surface waves[J].Journal of the Acoustical Society of America,1992,92(5):2527-2531. |
|
[11]
|
ZHAO Y,YAN W,SHEN Zh H,et al.Numerical simulation of elastic acoustic wave interaction with surface-breaking defects[J].Laser Technology,2010,34(1):91-94(in Chinese). |
|
[12]
|
ROYER D,CHENU C.Experimental and theoretical waveforms of Rayleigh waves generated by a thermoelastic laser line source[J].Ultrasonics,2000,38(9):891-895. |
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