Dynamics of a Submerged Ring-Stiffened Spherical Shell

The transient response of a ring-stiffened spherical shell to a sudden pressure increase in the surrounding acoustic medium is investigated. A modal expansion approach is used to analyze the shell, while the acoustic field equation is solved by invoking the Helmholtz integral. Coupling of the two fields occurs through the enforcement of continuity of the velocity components at the shell-fluid interface. Two solutions to the same problem are obtained by using plane and cylindrical wave approximations of the acoustic field. These approximate solutions fail to predict the transient behavior for the shell configuration analyzed. The result of this study indicates that a large dynamic factor must be assumed in the design of submerged, stiffened, spherical shell structures, if explosive loads are likely to be encountered.