title: Sound pulse broadening in stressed granular media.
abstract: The pulse broadening and decay of coherent sound waves propagating in disordered granular media are investigated. We find that the pulse width of these compressional waves is broadened when the disorder is increased by mixing the beads made of different materials. To identify the responsible mechanism for the pulse broadening, we also perform the acoustic attenuation measurement by spectral analysis and the numerical simulation of pulsed sound wave propagation along one-dimensional disordered elastic chains. The qualitative agreement between experiment and simulation reveals a dominant mechanism by scattering attenuation at the high-frequency range, which is consistent with theoretical models of sound wave scattering in strongly random media via a correlation length.
authors.affiliation: Université Paris-Est, Laboratoire Géomatériaux et Environnement (EA 4508), UPEM, F-77454 Marne-la-Vallée, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Langlois
authors.affiliation: Institut Langevin, ESPCI ParisTech, CNRS UMR 7587, 1 rue Jussieu, 75005 Paris, France and Université Paris-Est, 5 bd Descartes, 77454 Marne-la-Vallée Cedex 2, France.
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Jia