Damage response of submerged imperfect cylindrical structures to underwater explosion

The effect of the initial geometric imperfections to the damage response of submerged structures is investigated. The type of the submerged structure investigated is the ring-stiffened long circular cylinders submerged in the fluid. The strain hardening mild steel is used in the analysis. The type of the loading is the underwater shock induced by underwater explosions. The modal imperfection concept has been used to simulate the initial geometric imperfections. The numerical analyses were performed to look into the details of damage response of ring-stiffened cylindrical shells. The following models were considered: (i) three-dimensional infinite ring-stiffened cylinder model, and (ii) three-dimensional finite ring-stiffened cylinder model. A finite element hydrocode was used to numerically predict model responses.