Dynamic failure of clamped metallic circular plates subjected to underwater impulsive loads

The dynamic response and failure of monolithic metallic plates subjected to water-based impulsive loads are investigated experimentally. The analysis focuses on the effects of plate thickness, fluid-structure interaction parameter, and patch size of loading area on deformation and failure modes in clamped solid 5A06 aluminum alloy plates under air-backed and water-backed loading conditions. The plates are subjected to impulsive loads of different intensities using a projectile-impact based underwater non-contact explosive simulator. 3D digital imaging correlation method is used to capture the dynamic response of plates to make comparison with postmortem analysis. Depending on the loading rate, the inelastic deformation is the primary failure mode of the plates. The different linear relationships between deflection resistance and applied impulse are identified experimentally, considering the influences of the effects of plate thickness, fluid-structure interaction parameter, and patch size of loading area. The results show that the effect of loading area is the most influential factor on transverse deflection. The results affirm that the plate under water-backed condition shows a 53% reduction in the maximum plate deflection compared with the plate under air-backed condition. Quantitative structure-load-performance relation is carried out to facilitate the advanced study on metallic structures and provides guidance for structural design.