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 105 to 107. 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.