Non-destructive testing of composite plates by holographic vibrometry

Francois Bruno (1) , Jérôme Laurent (1) , Claire Prada (1) , Benjamin Lamboul (2) , Bruno Passilly (2) , Michael Atlan (1)

1 IL - Institut Langevin - Ondes et Images (UMR7587)
2 ONERA - The French Aerospace Lab [Châtillon]

We report on a wide-field optical monitoring method for revealing local delaminations in sandwich-type composite plates at video-rate by holographic vibrometry. Non-contact measurements of low frequency flexural waves is performed with time-averaged heterodyne holography. It enables narrowband imaging of local out-of-plane nanometric vibration amplitudes under sinusoidal excitation, and reveals delamination defects, which cause local resonances of flexural waves. The size of the defect can be estimated from the first resonance frequency of the flexural wave and the mechanical parameters of the observed layer of the composite plate.

Mots clés: laser doppler; vibrometry; heterodyne; holography; surface acoustic waves; COMPOSITE plates; Delamination NONDESTRUCTIVE testing

Domaines: Optique [physics.optics]; Instrumentations et Détecteurs [physics.ins-det]; Physique [physics]; Acoustique [physics.class-ph]

Francois Bruno, Jérôme Laurent, Claire Prada, Benjamin Lamboul, Bruno Passilly, et al.. Non-destructive testing of composite plates by holographic vibrometry. Journal of Applied Physics, 2014, 115 (15), pp.4. ⟨10.1063/1.4871178⟩. ⟨hal-00934264⟩