Dynamic response of spherical shells subjected to the underwater impulse

The dynamic response of spherical shells under impact loads is investigated experimentally. The analysis focuses on the effects of flyer velocity, shell thickness, and shell curvature radius on shell deformation. The spherical shells are subjected to underwater shock waves of different intensities using a projectile-impact-based underwater shock tube. The dynamic response of the spherical shell is captured by the method of three-dimensional digital image correlation with high-speed photography. The response mechanism of the spherical shells is analyzed by the method of experiment and numerical simulations. The results show that the residual displacement of the center point of the target plate has a nonlinear relationship with the thickness and curvature radius of the target plate under the same underwater impact load. The slope of the residual displacement-curvature radius curve of the center point of the target plate increases with the decrease of the thickness under the same thickness, and the slope of the residual displacement-thickness curve of the center point of the target plate increases with the increase of the curvature radius under the same curvature radius. Quantitative structure–load–performance relation is carried out to facilitate the advanced study of metallic structures and guide the impact resistance design of spherical shells in marine structures.