Material characterization and resonant scattering by cylinders

The resonant scattering of a plane acoustical wave in normal incidence by penetrable cylinders and tubes is considered. A numerical investigation of the dependence of the resonance parameters (frequency and width) on the bulk properties of the scatterer (density, shear and longitudinal velocities) has been carried out. The results offer the possibility of an acoustical spectral determination of the material composition of the target. A technique, called MECA, is given for determining the bulk wave velocities of cylindrical scatterers, using only the resonance frequencies which are easy to obtain with good accuracy. In the case of thin shells, the MECA is used to determine the thickness and the shear velocity, independently of the thickness. The technique is tested on experimental data