Dynamic response of hull girder subjected to combined underwater explosion and wave induced load

Abstract

Underwater explosion (UNDEX) is one of the major threats to the vitality and sustained combat ability of the warship in the marine military confrontation with both attack and defense. Although there have been plenty of researches focusing on the UNDEX load and its damage effect, the failure mechanism of the structure under the combined UNDEX and wave induced load, especially in extreme sea conditions, is still unrevealed. In this paper, a method for calculating the dynamic response of the hull girder subjected to the combined UNDEX and wave induced load is proposed, in which the acoustic–structure interaction method was employed for determining the UNDEX load, and the wave induced response of hull girder was derived by using hydrodynamic to structure (HTS) calculation procedure. The synergistic effect of the combination of different levels of wave induced load and the underwater explosion was analyzed. It is found that the hull girder is more dangerous under the combined UNDEX and wave induced load, especially in the severe wave level. The damage severity of the hull girder will be underestimated without considering the synergistic effect of the combined loads.