Study on structural response of water-back plate under the combined action of shock wave and bubble loads generated by cylindrical charge in deep-water environment

Abstract

The structural response of the water-back plate under the combined action of shock wave and bubble loads at water depths of 1–300 m is investigated numerically using an arbitrary Lagrange–Euler method. The accuracy of the numerical model is verified by a comparison with the shallow-water experimental results and theoretical results. Specifically, the influences of the water depth and length-to-diameter ratio of the cylindrical charge on the combined damage effect of the shock wave and bubble loads are analysed. The following conclusions are drawn. As water depth increases from 1 m to 300 m, the plastic deformation energy of the water-back plate decreases, meanwhile the permanent deformation mode of a water-backed plate changes from convex to concave under the combined action of shock wave and bubble loads; when the charge has large length-to-diameter, the plastic deformation energy of radial plate under combined action of the shock wave and bubble loads is higher than that of axial plate at water depths of 1–300 m, and both difference decrease with increasing water depth; the combined damage effect of the shock wave and bubble loads can be enhanced in the radial direction by increasing the length-to-diameter ratio in deep-water environments. When the length-to-diameter ratio increases from 1:1 to 8.2:1, the plastic deformation energy of the radial plate gradually increases by 7.58 % from 10.68 to 11.49 J.