Damage Characteristics of Box-like Beam as a Bulk Subjected to Underwater Explosion in Near-field.

When warship acts against underwater near-field explosion and coupling resonant motion takes place, the damage characteristics of the warship deserves an advanced research. A box-like beam was designed as an object floating on water, and a numerical simulation method was presented to study on the dynamic response of the beam subjected to underwater explosion located closely. Finally, experiments were carried out to verify the simulation method. The results show that numerical results agree well with experimental ones, and it proves the method reasonable. When the first-order mode frequency of beam is close to that of underwater explosion bubble oscillation, with the increase of the ratio of stand-off to maximum bubble radius, the response mode of beam will take a change from plastic bending in sagging condition into elastic whipping motion. [ABSTRACT FROM AUTHOR]