Cumulative Damage Effects of Repeated Underwater Explosions on Multi-Cabin Structures

This paper presents experimental and numerical findings regarding complex multi-cabin structures with the goal of elucidating cumulative damage mechanisms and assessing the influence of blast distance on damage characteristics under repeated underwater explosions. The damage characteristics of a multi-cabin structure were analyzed through single and repeated explosion tests employing equal-mass charges. The shockwave loads and structural damage observed during testing were accurately predicted through numerical simulations, which revealed that the structure experienced the combined impact of shockwaves, transmitted pressure waves, and bubble expansion loads during repeated explosions. The findings demonstrate that repeated underwater explosions produce a cumulative damage effect, leading to a significant increase in the extent of depression plastic deformation and deflection of the structure. However, the gain in cumulative damage effects is limited compared to a single explosion with an equivalent charge. A single explosion results in extensive tearing and dent deformation of the structure, causing far more severe damage than repeated explosions.