A mitigation scheme for underwater blast: Experiments and modeling

A novel but relatively easy-to-implement mitigation concept to enforce standoff distance and reduce shock loading on a vertical, partially-submerged structure is evaluated experimentally using scaled aquarium experiments and numerically using a high-fidelity finite element code. Scaled, watertamped explosive experiments were performed using aquariums of different sizes. The effectiveness of different mitigation configurations, including air-filled media and an air gap, is assessed relative to an unmitigated detonation using the same charge weight and standoff distance. Experiments using an airfilled media mitigation concept effectively dampen the explosive response of an aluminum plate and reduce the final displacement at plate center by approximately half. Experiments using an air-gap resulted in a focused water slug hitting the plate, an effect we hypothesize to be due to water encasement of the charge. Finite element simulations used for the initial experimental design compare very well to experiments ...