On the splitting of aspherical structure submitted to an acoustic polarized excitation.
We experimentally show how the deviations from spherical symmetry such as the inhomogeneity, the removal mass or the asphericity affect the frequency spectrum of a single elastic sphere. The recorded spectrograms point out the great influence of the polarization of the source on the splitting and the shift of the peaks. Qualitatively, the results are consistent with the data reported in Geophysics although the present study is concerned with a low degree and low- [Formula: see text] modes in contrast to those usually encountered in seismic investigations. From a practical point of view, this study suggests that Geophysics phenomena could be analyzed through spherical beads reproducing the imperfections encountered in the mantle and in the core of the earth.
de Billy
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Laboratoire Environnement et Développement, Université Paris 7, Tour 33, Boite Postale 70 87, 2 Place Jussieu, 75251 Paris Cedex 05, France. mdebilly@ccr.jussieu.fr
Hladky-Hennion
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