Eur. Phys. J. AP 9, 69-73 (2000)
https://doi.org/10.1051/epjap:2000202

Shearographic visualization of lamb waves in carbon epoxy plates interaction with delaminations^*

ONERA, Department of Solid Mechanics and Damage, B.P. 72, 29 avenue du Général Leclerc, 92332 Châtillon Cedex, France

Corresponding authors: taillade@onera.fr krapez@onera.fr lepoutre@onera.fr balageas@onera.fr

Received: 26 May 1999
Revised: 13 September 1999
Accepted: 23 September 1999
Published online: 15 January 2000

Abstract

This article presents an application of a speckle interferometry technique with video doubling, called "shearography". This technique can be used for near real time imaging of Lamb waves in continuous or burst modes, revealing the presence of delaminations in a carbon epoxy plate. The amplitude of the displacements is measured with a typical uncertainty of the order of 1 nm. The nominal Lamb wave can be suppressed from the shearographic image by optical filtering, to show only the wave interaction with any defects that may exist in the plate. This method is especially advantageous for non-destructive testing.