Vibration of Hemi-Ellipsoidal Axisymmetric Domes Submerged in Water

Ten thin-walled domes, of hemi-ellipsoidal form, were vibrated in air and while partially and fully submerged in water. The domes varied in shape from oblate ones of aspect ratio (AR) 0.25 to prolate ones of aspect ratio 4. The fundamental modal patterns for the oblate domes tended to be of axisymmetric form, while the fundamental modal patterns of the hemispherical and prolate domes tended to be of asymmetric or lobar form. The theoretical analysis was carried out by the finite element method, where the motion of the shell structure was represented by three different types of element and the motion of the water was represented by a solid annular element. Comparison between theory and experiment was found to be good.