A spectral-element/finite-element analysis of a ship-like structure subjected to an underwater explosion

The practicability of an improved procedure for simulating the response of a surface ship to an underwater explosion is demonstrated by examining transient responses for a 31,000-degree-of-freedom finite-element model of ship-like structure. The fluid model employs spectral elements of various order, and models the cavitating fluid as a nonlinear acoustic medium with a bilinear bulk modulus. The number of fluid degrees of freedom ranges from 10 5 to 10 7. Also studied is the viability of dramatic mesh truncation, which is essential to the feasibility of the procedure. The results indicate that useful simulations may be performed on a modern PC when all of the resource-conserving improvements are fully exploited.