Abstract:Both the shock wave and the bubble load from underwater explosion can destroy the structures. In order to study the plastic displacement of the stiffened plates subjected to underwater explosion bubble, the dynamic plastic response of the model were simulated by using FEM software Abaqus/Explicit. The underwater explosion load was calculated by use of the Geers-Hunter model. The material was simulated by Johnson-Cook conditions. The simulation results were coincident with the experimental ones. The results show that the effect to the plastic displacement of the stiffened plates subjected to underwater explosion bubble relates to the standoff distance. In the near field explosion, the effect of the bubble is more important. Therefore, the plastic displacement induced by bubble load can’t be neglected in the near field explosion.