Numerical study on dynamic buckling of a cylindrical shell subjected to underwater explosion

Dynamic buckling of a submerged cylindrical shell subjected to underwater explosion (UNDEX) is numerically investigated by coupled acoustic-structural analysis with ABAQUS/Explicit. The total wave algorithm is adopted due to cavitation induced by fluid-structure interaction, and the critical buckling load is predicted by the Budiansky-Roth criterion. Three failure modes closely related to the immersion depth and charge mass are observed, and numerical results indicate shock wave and bubble pulsation generated by UNDEX lead to completely different buckling modes of the cylindrical shell. For the small immersion depth and charge mass, shock wave results in local buckling near both ends of the shell due to stress concentration and stress wave propagation. With the increase of the charge mass or the immersion depth, the local buckling observed in the shock wave stage evolves to global buckling in the middle region of the shell during the subsequent bubble pulsation stage. However, the further increase of the immersion depth results in a significant increase in the bubble pulsation load. Then, although the shock wave below the critical buckling load can not cause local buckling of the shell, the subsequent bubble pulsation directly results in global buckling in the middle region of the shell.