A novel fluid–structure interaction modelling approach for vibro-acoustic simulation of ship hulls subjected to underwater shock waves

Understanding the dynamic response of naval structures subjected to underwater explosions (UNDEX) is crucial for offshore and marine engineering applications. This study presents a novel fluid-structure interaction (FSI) modelling strategy to simulate the vibro-acoustic response of hull structures impacted by far-field UNDEX, balancing computational efficiency and accuracy. A hybrid 1-D/3-D numerical approach is proposed to simulate far-field pressure wave propagation and near-field effects, FSI and structural response. MSC Dytran is employed for UNDEX simulation and FSI, while Actran VI is used for the subsequent vibro-acoustic analysis. The method enables the assessment of structural deformation, induced vibrations, and structure-borne noise in a representative ship section. The findings highlight the importance of integrating vibro-acoustic evaluations into UNDEX analyses and demonstrate the advantages and limitations of the proposed approach in terms of computational cost and accuracy, discussing future improvements to enhance efficiency and applicability in industrial and research contexts. HIGHLIGHTS: A combined 1-D–3-D model is developed to study far-field UNDEX with reduced computational costs. Structural dynamic analysis is coupled with vibro-acoustic simulation to study UNDEX effect. Structural deformation, Von Mises stress, induced vibrations, and radiated noise are evaluated. Vibration and noise levels are useful for the design of equipment and safety devices for the crew on board. The proposed numerical modelling is reliable and useful in the preliminary engineering design of marine vessels.