In order to evaluate the safety of a submerged structure subjected to UNDerwater EXplosion (UNDEX) loads, it is necessary to estimate the structural response accurately.
This paper describes the experimental results and numerical simulation results of UNDEX test using thin and thick cylindrical shells. From this study, fluid-structure interaction effects to peak value, waveform and impulse intensity of surface pressure are discussed. And, it is shown that surface pressure of thin cylindrical shell is strongly influenced by surface cavitation. Further, it is shown that the reasonably modified numerical simulation results have very good agreement with the experimental results, and the mutual comparison between experimental results and numerical simulation results is helpful to estimate the true peak pressure.