ACOUSTICAL AND MECHANICAL CHARACTERIZATION OF ANISOTROPIC OPEN-CELL FOAMS

Acoustical (viscous static permeability, tortuosity, and viscous chara cteristic length) and mechanical (skeleton viscoelasticity tensor) par ameters which characterize the behavior of porous media are provided f rom measurements along three perpendicular axes. The measurements are performed on cubic samples of open-cell foams. The longitudinal direct ion is chosen to be parallel to the growth direction of the foam. The results show that the samples tested here exhibit a quasi-axisymmetric al geometry. It appears that a precise description of this type of ret iculated polymeric foam must include its anisotropy, especially for vi broacoustic behavior prediction. (C) 1998 Acoustical Society of Americ a. [S0001-4966(98)02311-X].