6533b82cfe1ef96bd12905c5

RESEARCH PRODUCT

Study of acoustic properties and impact behavior of porous materials homogeneous type metal foams and inhomogeneous

Carlos Javier Sacristán López-mingo

subject

[SPI.ACOU] Engineering Sciences [physics]/Acoustics [physics.class-ph]Macroscopically inhomogeneous materialsImpacts mécaniquesAcoustical propertiesPropriétés acoustiquesMechanical impactsMousses métalliquesParallel transfer matricesMatrices de transfert en parallèleMatériaux macroscopiquement inhomogènesMetallic foams[SPI.MECA.MEMA] Engineering Sciences [physics]/Mechanics [physics.med-ph]/Mechanics of materials [physics.class-ph]

description

This work is concerned with the theoretical and experimental study of the acoustical properties of macroscopically homogenous and inhomogeneous porous media as well as their mechanical response to impacts. The model of Johnson - Champoux - Allard appeared adapted for the acoustical modeling. This model, associated with a recently developed approach involving the concept of parallel transfer matrices has lead to a new approach of macroscopically inhomogeneous porous materials based on “mixtures of materials”. Furthermore, a parametric study of the absorption coefficient as a function of porosity and frequency has been proposed. The maximums of absorption as well as the envelop of the absorption curves have been studied as functions of porosity. First, a theoretical material with independent parameters has been studied. Real materials with nonindependent parameters were then investigated with the help of a model relating their properties to the porosity. Finally, a comparison between the acoustical and mechanical properties has been initiated in view of determining an objective criterion that will allow to propose a trade off between the two fields.

https://theses.hal.science/tel-01257760