David C. Ricks
Henrik Schmidt
Dept. of Ocean Eng., MIT, Cambridge, MA 02139
A multi-layered cylindrical shell is modeled with the direct global matrix approach (DGM). The DGM approach allows the shell to have multiple viscoelastic layers, which are modeled with the full 3-D equations of elastodynamics. The DGM formulation is numerically stable for the wave types of interest (membrane compression, membrane shear, and flexural waves). The shell also contains a thin elastic bulkhead, which is modeled with the Mindlin thin plate theory. This coupled system is excited by obliquely incident plane waves in a fluid medium that surrounds the shell. The scattering caused by the bulkhead is computed. The effects of viscoelastic layers are investigated. [Work supported by ONR.]