Abstract
Laser ultrasonics is a technique where lasers are used for the generation and detection of ultrasound instead of conventional piezoelectric transducers. The technique is broadband, non-contact, and couplant free, suitable for large stand-off distances, inspection of components of complex geometries and hazardous environments. In this paper, array imaging is presented by obtaining the full matrix of all possible laser generation, laser detection combinations in the array (Full Matrix Capture), at the nondestructive, thermoelastic regime. An advanced imaging technique developed for conventional ultrasonic transducers, the Total Focusing Method (TFM), is adapted for laser ultrasonics and then applied to the captured data, focusing at each point of the reconstruction area. In this way, the beamforming and steering of the ultrasound is done during the post processing. A 1-D laser induced ultrasonic phased array is synthesized with significantly improved spatial resolution and defect detectability. In this study, shear waves are used for the imaging, since they are more efficiently produced than longitudinal waves in the nondestructive, thermoelastic regime. Experimental results are presented from nondestructive, laser ultrasonic inspection of aluminum samples with side drilled holes and slots at depths varying between 5 and 20mm from the surface.
| Original language | English |
|---|---|
| Title of host publication | 43rd Annual Review of Progress in Quantitative Nondestructive Evaluation, Volume 36 |
| Editors | Dale E. Chimenti, Leonard J. Bond |
| Place of Publication | Melville, NY |
| Number of pages | 9 |
| Volume | 1806 |
| DOIs | |
| Publication status | Published - 16 Feb 2017 |
| Event | 43rd Annual Review of Progress in Quantitative Nondestructive Evaluation, QNDE 2016 - Atlanta, United States Duration: 17 Jul 2016 → 22 Jul 2016 |
Conference
| Conference | 43rd Annual Review of Progress in Quantitative Nondestructive Evaluation, QNDE 2016 |
|---|---|
| Country | United States |
| City | Atlanta |
| Period | 17/07/16 → 22/07/16 |
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Keywords
- laser ultrasonics
- non-contact
- array imaging
- full marix capture
- thermoelastic regime
- total focusing method
- shear waves
Cite this
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Full matrix capture and the total focusing imaging algorithm using laser induced ultrasonic phased arrays. / Stratoudaki, Theodosia; Clark, Matt; Wilcox, Paul D.
43rd Annual Review of Progress in Quantitative Nondestructive Evaluation, Volume 36. ed. / Dale E. Chimenti; Leonard J. Bond. Vol. 1806 Melville, NY, 2017. 020022.Research output: Chapter in Book/Report/Conference proceeding › Conference contribution book
TY - GEN
T1 - Full matrix capture and the total focusing imaging algorithm using laser induced ultrasonic phased arrays
AU - Stratoudaki, Theodosia
AU - Clark, Matt
AU - Wilcox, Paul D.
PY - 2017/2/16
Y1 - 2017/2/16
N2 - Laser ultrasonics is a technique where lasers are used for the generation and detection of ultrasound instead of conventional piezoelectric transducers. The technique is broadband, non-contact, and couplant free, suitable for large stand-off distances, inspection of components of complex geometries and hazardous environments. In this paper, array imaging is presented by obtaining the full matrix of all possible laser generation, laser detection combinations in the array (Full Matrix Capture), at the nondestructive, thermoelastic regime. An advanced imaging technique developed for conventional ultrasonic transducers, the Total Focusing Method (TFM), is adapted for laser ultrasonics and then applied to the captured data, focusing at each point of the reconstruction area. In this way, the beamforming and steering of the ultrasound is done during the post processing. A 1-D laser induced ultrasonic phased array is synthesized with significantly improved spatial resolution and defect detectability. In this study, shear waves are used for the imaging, since they are more efficiently produced than longitudinal waves in the nondestructive, thermoelastic regime. Experimental results are presented from nondestructive, laser ultrasonic inspection of aluminum samples with side drilled holes and slots at depths varying between 5 and 20mm from the surface.
AB - Laser ultrasonics is a technique where lasers are used for the generation and detection of ultrasound instead of conventional piezoelectric transducers. The technique is broadband, non-contact, and couplant free, suitable for large stand-off distances, inspection of components of complex geometries and hazardous environments. In this paper, array imaging is presented by obtaining the full matrix of all possible laser generation, laser detection combinations in the array (Full Matrix Capture), at the nondestructive, thermoelastic regime. An advanced imaging technique developed for conventional ultrasonic transducers, the Total Focusing Method (TFM), is adapted for laser ultrasonics and then applied to the captured data, focusing at each point of the reconstruction area. In this way, the beamforming and steering of the ultrasound is done during the post processing. A 1-D laser induced ultrasonic phased array is synthesized with significantly improved spatial resolution and defect detectability. In this study, shear waves are used for the imaging, since they are more efficiently produced than longitudinal waves in the nondestructive, thermoelastic regime. Experimental results are presented from nondestructive, laser ultrasonic inspection of aluminum samples with side drilled holes and slots at depths varying between 5 and 20mm from the surface.
KW - laser ultrasonics
KW - non-contact
KW - array imaging
KW - full marix capture
KW - thermoelastic regime
KW - total focusing method
KW - shear waves
UR - http://www.scopus.com/inward/record.url?scp=85016002099&partnerID=8YFLogxK
UR - http://aip.scitation.org/toc/apc/1806/1?expanded=1806
U2 - 10.1063/1.4974563
DO - 10.1063/1.4974563
M3 - Conference contribution book
SN - 9780735414747
VL - 1806
BT - 43rd Annual Review of Progress in Quantitative Nondestructive Evaluation, Volume 36
A2 - Chimenti, Dale E.
A2 - Bond, Leonard J.
CY - Melville, NY
ER -