Dynamic Response Characteristics of Stiffened Cylindrical Shells Subjected to Deep-Water Explosion

In deep-water environments, the combined effects of hydrostatic pressure, explosion-induced shock waves, and bubble pulsation can produce complex nonlinear dynamic responses and instability in stiffened cylindrical shells. Clarifying these response mechanisms is critical for the safety assessment and blast-resistant design of deep-sea equipment. In this study, an acoustic–structural coupled numerical method was developed for stiffened cylindrical shells subjected to underwater explosion loading and validated using deep-water explosion tests conducted in a pressure vessel. The numerical results show that the relative error between the numerical and experimental wall-pressure impulses on the blast-facing surface is 3.6%, while the relative error in the maximum compressive strain at a representative measurement point on the blast-facing surface is 15.6%, indicating that the established numerical model can reasonably reproduce the pressure impulse and the primary dynamic response of the structure. Based on this validated model, a systematic investigation was conducted to evaluate the effects of hydrostatic pressure, stand-off distance, shell-plate thickness, and stiffener number on the deep-water explosion response of stiffened cylindrical shells. With increasing water depth, the structural deformation mode transitions from localized plastic indentation to global instability and crushing. The findings provide practical guidance for blast-resistant design and parameter optimization of deep-water stiffened cylindrical shells.