SURFACE SHIP SHOCK MODELING AND SIMULATION - 2-DIMENSIONAL ANALYSIS

The modeling and simulation of the response of a surface ship system t o underwater explosion requires an understanding of many different sub ject areas. These include the process of underwater explosion events, shock wave propagation, explosion gas bubble behavior and bubble-pulse loading, bulk and local cavitation, free surface effect, fluid-struct ure interaction, and structural dynamics. This paper investigates the effects of fluid-structure interaction and cavitation on the response of a surface ship using USA-NASTRAN-CFA code. First, the one-dimension al Bleich-Sandler model is used to validate the approach, and second, the underwater shock response of a two-dimensional mid-section model o f a surface ship is predicted with a surrounding fluid model using a c onstitutive equation of a bilinear fluid which does not allow transmis sion of negative pressures.