Surrogate approaches to predict surface ship response to far-field underwater explosion in early-stage ship design

Abstract

Numerical simulation of a far-field underwater explosion (UNDEX) and its interaction with a large ship structure is a computationally intensive task requiring the discretization of a large fluid domain. This paper explores surrogate non-numerical approaches to approximate surface ship structural response to far-field UNDEX based on a now classic shock factor approach proposed by Keil (Keil 1961). Instead of the entire time domain history, this work focuses on peak structural responses, which may provide valuable information to guide equipment arrangement in early-stage ship design to minimize shock effects. The shock factor response equation as proposed by Keil is refined to improve its performance in predicting peak structural responses at different locations in the ship. This refinement is accomplished by a regression analysis using ship structural responses obtained from numerical simulation and their corresponding shock factor values. The results show that the refined relationship between shock factor and peak structural response is promising. As a result, the shock factor may be employed to approximate peak structural response. Also, the feasibility of using an analytical model to obtain data for regression in replacement of the numerical model is assessed. Lastly, an application example using the shock factor is presented.