Damage mechanisms of underwater explosive bubble on water-filled bilayer shells

The study of the dynamic behaviors and load characteristics of underwater explosion bubbles near stationary boundaries may not fully apply to cases involving boundary motion. Numerical simulations were utilized to explore the damage mechanisms induced by an underwater explosion bubble on a mobile water -filled bilayer spherical shell structure. The response characteristics of the structure to underwater blast loads during its journey towards the explosive center were analyzed. The investigation indicates that: An increase in structural velocity can reduce the count of bubble pulsations. The maximum scale and moment of emergence of the bubble exhibit a linear relationship with the sailing velocity. However, the wall pressure caused by pulsating load shows a nonlinear correlation with it. The approach of the structure towards the bubble may trigger the formation of reverse water jet, significantly altering the velocity, width, initiation process, impact position, and load intensity of bubble collapse water jet. Higher structural velocities generally exacerbate shell damage, with a range of sailing speeds identified as efficiently damaging the shell. Reductions in the number of bubble pulsations and earlier breakdowns of bubbles by reverse water jet can intensify the loading of bubble load on the shell and alter the shell's damage mode.