On the measurement of the mechanical properties of acoustic porous materials

Abstract

This paper discusses the measurements and use of the mechanical properties of porous materials. It starts with a review of the classical methods currently used and concentrates in explaining the assumptions, difficulties and limitations of these methods. Next, it concentrates on two methods: a quasi-static approach accounting for the effect of shape factors on the measured properties and a hybrid inverse method similar to the vibrating beam method used for viscoelastic materials. Through full 3-D numerical simulations, both methods are simulated and their main features, assumptions, and limitations are investigated. In particular, the model uses full poro-elastic modeling and boundary element in order to investigate the effect of acoustic radiation damping and viscous damping. Using various types of materials, comparisons between these two methods and experimental data are also discussed.