The one-dimensional response of a water-filled double hull to underwater blast: Experiments and simulations

• Laboratory-scale underwater shock experiments and FE simulations were performed.
• Experiments were conducted in a water-filled transparent shock tube.
• Structural responses as well as cavitation processes in the fluid were observed.
• Sandwich construction of the hull can reduce the impulse imparted to the structure.
• Impulse reductions are scarcely sensitive to the thickness of the water layer.

Laboratory-scale fluid–structure interaction (FSI) experiments and finite element (FE) simulations are performed to examine the one-dimensional blast response of double-walled hulls, consisting of two skins sandwiching a layer of water. Both monolithic and sandwich designs are considered for the outer skin. Experiments are conducted in a transparent shock tube which allows measurements of water cavitation and hull response by high-speed photography. Experiments and FE predictions are found in good agreement and allow concluding that the impulse imparted to double hulls by underwater explosions can be dramatically reduced by employing the sandwich construction of the outer skin; such reductions are scarcely sensitive to the thickness of the water layer.