Thibault Wassereau

• PhD in acoustics
• Engineer at Sonorhc Technologies

The detection and precise location of threats is a subject of prime importance in both the military and civilian fields. Although requiring a triggering event for detection, acoustic methods can help locate its origin. Conventional acoustics methods are generally very effective in a free or open field, because the acoustic waves generated by a shot...

div class="section abstract"> This paper aims at identifying the flexural and shear complex moduli of a sandwich beam by simply measuring the displacement field and applying an inverse resolution of the Timoshenko beam problem. A first development [ 1 ] employed the RIFF technique (from the french "Resolution Inverse Filtrée Fenêtrée") [ 2 ]. This...

In this article, an improvement of [1] is proposed, in order to identify the flexural and shear complex moduli of a sandwich beam by simply measuring the displacement field. The method described here involves a correction of finite the difference scheme 5

This paper addresses the problem of estimating the local viscoelastic parameters of sandwich beams. An original procedure involving an inverse vibratory method (Force Analysis Technique) and the Timoshenko beam theory is detailed and applied experimentally on a sample presenting a honeycomb core. The major philosophy relies in considering multi-lay...

L’usage croissant des matériaux composites dans l’industrie induit de nouvelles problématiques dans des domaines variés, notamment pour la caractérisation non destructive. Les méthodes courantes comme l’analyse modale ou les éléments finis sont rarement adaptées pour représenter la dynamique vibratoire complexe des structures composites ou quantifi...

This paper describes an optical set-up for measuring density fluctuations associated to acoustic oscillations in a thermoacoustic prime-mover. A time-resolved, full-field holographic interferometry technique is used, which enables to measure the optical phase difference between a reference beam and a probe beam passing through the acoustic resonato...

This work aims at analyzing structures by mean of an inverse vibratory method consisting in an evolution of the Force Analysis Technique. The latter developed by Pézerat et al. firstly allowed localization and quantification of vibratory sources from measurement of the displacement field. In 2012 Ablitzer et al. improved the procedure for character...

Cet article présente un dispositif d’interférométrie holographique avec deux longueurs d’ondes et deux capteurs d’images, dont les cadences d’acquisitions sont différentes, pour caractériser les auto-oscillations générées dans un moteur thermo-acoustique à onde stationnaire. Les résultats expérimentaux devraient permettre une meilleure compréhensio...

This paper proposes a digital holographic set-up with two wavelengths and two image sensors, having different acquisition frame rates, to characterize the acoustic auto-oscillations generated in a standing-wave thermo-acoustic generator.