Hydrodynamic and structural responses of air-cushion vehicle skirt exposed to underwater explosions

• Response of an air-cushion vehicle skirt to underwater explosion is examined. • Coupled hydrodynamic and structural skirt behaviours are characterised. • Detonation distance deterministically affects plough-in occurrence. The skirts of air-cushion vehicles (ACVs) are subjected to highly nonlinear loads, which can compromise their stability and strength when exposed to underwater explosions. However, only a few studies have investigated the scenario of ACV skirts subjected to slamming loads or treated them as rigid bodies. Therefore, the aim of this study was to examine the hydrodynamic and structural responses of an ACV skirt under underwater explosion conditions. A numerical model was developed by coupling the control volume approach with the arbitrary Lagrangian–Eulerian method to examine these responses and was validated through a benchmark experiment. The results show that the occurrence of the plough-in phenomenon is governed by the detonation distance rather than charge weight. Given the complexity of the load, deformation, and maximum principal stress profiles, the corresponding numerical results should be used for evaluating the stability and strength of ACVs without simplification. The results of this study offer valuable guidelines for ACV design and navigation.