title: Dispersion of circumferential waves on evacuated, water-loaded spherical steel shells.
abstract: The phase-velocity dispersion curve of the A0 Lamb wave on a free plate tends to zero at the vanishing frequency while on an evacuated, free spherical shell, it turns upward. On a fluid-loaded shell, and for the analogous circumferential A0 wave, it again tends to zero, however, while a new A-wave (Scholte-Stoneley wave) which gets added due to fluid loading, is the one whose dispersion curve turns upward. This phenomenon is studied here for a thin stainless-steel shell on the basis of dispersion curves calculated from 3D elasticity theory, or obtained from the calculated shell resonances, and is explained by the physical nature (shell-borne or fluid-borne) of appropriate circumferential wave portions. We also establish connections with the previously found partial dispersion curves.
authors.affiliation: Department of Industrial Acoustics, Technical University of Denmark, Lyngby.
authors.forename: H
authors.initials: H
authors.lastname: Uberall
authors.forename: I K
authors.initials: IK
authors.lastname: Bjørnø
authors.forename: L
authors.initials: L
authors.lastname: Bjørnø
mesh_terms: D000162:Acoustics