Titre :

PZT array for passive guided wave tomography of extended defects using ambient elastic noise cross-correlations

Auteur(s) :

Druet, Tom [Auteur]
Transduction, Propagation et Imagerie Acoustique - IEMN [TPIA - IEMN]
Chapuis, Bastien [Auteur]
Manfred, Jules [Auteur]
Laffont, Guillaume [Auteur]
Moulin, Emmanuel [Auteur]
Transduction, Propagation et Imagerie Acoustique - IEMN [TPIA - IEMN]
Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 [IEMN]

Titre de la manifestation scientifique :

7th International Symposium on NDT in Aerospace

Ville :

Bremen (GERMANY)

Pays :

Allemagne

Date de début de la manifestation scientifique :

2015-11-16

Titre de l’ouvrage :

Proceedings of 7th International Symposium on NDT in Aerospace

Discipline(s) HAL :

Sciences de l'ingénieur [physics]

Résumé en anglais : [en]

Structural health monitoring (SHM) consists in embedding sensors in astructure like an aircraft or a naval ship in order to detect defects (for examplecracks or corrosion in metallic materials or delamination in composite ...
Lire la suite >Structural health monitoring (SHM) consists in embedding sensors in astructure like an aircraft or a naval ship in order to detect defects (for examplecracks or corrosion in metallic materials or delamination in composite materials)before a serious fault occurs in the structure. Guided elastic waves emitted by asensor and propagating to another one are often used as the physical way ofdetecting the defect. However, the implementation of SHM systems is restricted inmany situations by the necessity to store or to harvest the electric energy necessaryto emit the waves.A promising way to tackle this constraint is to use techniques based on thecross-correlations of the ambient acoustic noise in place in the structure. It has beenshown that, under certain conditions, transient response between two sensors can beestimated from cross-correlation of ambient noise, with purely passivemeasurements.The idea is to take advantage of the elastic noise naturally present in thestructure (due to engine vibrations or aero-acoustic turbulences on the fuselage of anaircraft for example) in order to avoid the emission of the elastic waves by the SHMsystem. The complexity of the embedded SHM system is therefore reduced.We present here studies of noise cross-correlation techniques that have beenconducted with the aim of doing passive tomography of extended defects (such ascorrosion or delamination) using an array of piezoelectric (PZT) transducers. Noiseis generated by spraying compressed air on the surface of an aluminum plate.Passive measurements are compared to active signals to demonstrate theconvergence of the cross-correlation technique to the Green function of the system.Experimental results which come from tomographic time-of-flight imagingalgorithms will also be described. Finally, an extension of this technique usingpurely passive guided wave sensors such as Fiber Bragg Grating (FBG) will bepresented.Lire moins >

Langue :

Anglais

Collections :

• Institut d'Électronique, de Microélectronique et de Nanotechnologie (IEMN) - UMR 8520

Source :

Harvested from HAL