Abstract

CASTRO-COLIN, M; LOPEZ, J.A.  and  OSEGUEDA, R. Identification of Laser - induced Lamb waves. Rev. mex. fis. [online]. 2007, vol.53, suppl.3, pp.12-15. ISSN 0035-001X.

We studied experimentally the ultrasonic propagating modes produced by a laser pulse of 532 nm while impinging on an aluminum plate. The beam, shaped as a line, induced various Lamb modes whose relative power varied with the laser line length. Identification of their mode was performed by detecting the ultrasonic modes with piezoelectric detectors along a propagation direction orthogonal to the line, and using two dimensional fast Fourier transform. Good agreement is observed between theoretical and experimental dispersion curves for the first fundamental symmetric and anti-symmetric modes. Results are shown for 12 and 24 mm laser line-length at 13.6 and 16.8 ns pulse-width.

Keywords : Laser based ultrasound; non-destructive testing; photoacoustic.

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