Investigation on the coupling damage effects of ships subjected to near-field underwater explosion loads

Near-field underwater explosions generate complex load forms and cause destructive strikes on ships. To investigate the damage characteristics of ships under the combined effect of multiple loads, local and overall damage modes were first investigated through the combination of experimental tests and numerical simulation. Then a series of numerical simulations of full-scale ships subjected to near-field underwater explosions with different stand-off distances, equivalents, and detonation positions were carried out. The damage effects of shock wave, bubble pulsation, after flow, and water jet loads on ships were analyzed. The results show that the combined effects of different loads lead to different damage modes. Shock waves and after flow loads are the main cause of local damage and hogging damage, while pressure difference and bubble adsorption are the main reasons for the hogging damage. Finally, a criterion was proposed to determine the damage modes of ships under near-field underwater explosions.