Recovery of the effective wavenumber and dynamical mass density for materials with inclusions

Guillaume Lepert , Christophe Aristégui (1) , Olivier Poncelet , Thomas Brunet (2) , Christian Audoly (3) , Patrick Parneix

1 LMP - Laboratoire de Mécanique Physique
2 I2M - Institut de Mécanique et d'Ingénierie de Bordeaux
3 DCNS

For many years, the study of material with locally resonant inclusions has known a great interest. Due to their attractive macroscopic acoustic properties, which do not exist in natural materials, many applications governed by the contrast between the constituent properties can be achieved/expected: cloaking, enhanced absorption, flat plate lens, wave trapping… Such structures containing inclusions are usually modeled as effective homogeneous materials with complex-valued and frequency-dependent effective wavenumber and mass density. In this context, we derived a method for the simultaneous determination of both parameters using an immersed sample. First, its reliability is demonstrated using theoretical input data with simulated measurement noise. Finally, the characterization method is applied to experimental waveforms measured on test panels made with materials designed in order to exhibit cavity resonances over the frequency range of study.

Mots clés: Characterization

Domaines: Acoustique [physics.class-ph]

Guillaume Lepert, Christophe Aristégui, Olivier Poncelet, Thomas Brunet, Christian Audoly, et al.. Recovery of the effective wavenumber and dynamical mass density for materials with inclusions. Acoustics 2012, Apr 2012, Nantes, France. ⟨hal-00811114⟩