A reanalysis of the acoustic scattering from elastic spheroids

The elastic response of fluid‐loaded, elastic spheroids to an end‐on incident acoustic wave is analyzed for a variety of aspect ratios and material properties. The focus of this analysis is the nature of the elastic excitations of the target, and, to a lesser extent, the nature of the inelastic background. It is concluded that the low kL/2, resonant response of the target is closely related to a bar wave, propagating at nearly one and one‐half times the shear speed at low frequencies and that the rigid body solution with recoil is the appropriate background choice for all materials. Bistatic scattering calculations are also studied, and it is concluded that the lobe structure of the elastically reradiated signal cannot be used to characterize a resonance without a priori knowledge of the target. The results contradict recent, but more phenomenologically oriented, studies.