Damage Characterization of Multi-cabin Structure by Near-Surface Underwater Explosion

In order to investigate the influence of the free liquid surface’s boundary effect and the blast load’s intensity on the damage and destruction characteristics of the multi-cabin structure under the near-surface underwater explosion conditions. In this paper, we conducted the underwater explosion test of the multi-cabin structure under typical conditions. The test conditions are reproduced using a structure-arbitrary Lagrange–Euler (S-ALE) coupled numerical simulation method. At the same time, according to the numerical simulation results, the characteristics of pressure load transfer and distribution in the flow field, the dynamic response, and failure characteristics of the structure under the condition of explosion near the water surface are analyzed. The results show that shear rupture, tensile tearing, and depressed plastic deformation regions are generated in the outer plate of the multi-cabin structure. The damaged form of the outer plate of the structure interferes with the transfer diffusion of the underwater blast load, leading to the asymmetric expansion motion of the blast bubble, which affects the load distribution characteristics of the cabin within the structure. Moreover, based on the numerical simulations of different blast equivalents and distances for multiple working conditions, the damage mechanism, the dynamic response characteristics, and damage and destruction modes of the multi-cabin structure are acquired.