Experimental study of damage to double-hull structure by underwater explosions of three charge types - blasting, shaped, and linear shaped charges

Abstract

In recent years, due to the improvement in ship protection capabilities, near-field underwater explosions no longer pose fatal damage to ships. Since stiffened plates are typical structures in ships, studying the impact of underwater explosions with different types of explosives on ships is of great significance. This experiment investigated the damage characteristics of blasting, shaped, and linear shaped charges on the same type of stiffened plate. The experimental results indicate that linear shaped charges can create larger penetration holes on target plates, but they suffer from insufficient flight capability. In contrast, shaped charges exhibit stronger penetrating power, yet they lack sufficient damage capability against target plates. Although the penetration capability of blasting charges is inferior to the first two, its overall deflection of the plate frame exceeds that caused by shaped charges and linear shaped charges by 1.6 % and 5.7 %, respectively. To further investigate the penetration process and the load characteristics of the penetrator, a finite element model was established in this paper. The numerical results show that there is no significant difference in jet length and velocity between the two models, but the shapes of the jet tips differ, and the computational results are in good agreement with the experimental results, confirming the validity of the Arbitrary Lagrangian-Eulerian (ALE) method.