Dynamic Response Characteristics of Ship-Like Beam Subjected to Underwater Explosion in Near Field

To study dynamic response and overall damage modes of warship subjected to underwater explosion in near field, a ship-like model was designed based on similarity criterion. The dynamic response was investigated by changing stand-off and weight of explosive in experiments where four kinds of explosives were located closely under the mid-span of the hull girder. In experiments, high-speed photography was applied to obtain the girder's movement process. Simultaneously, the data of strain and acceleration was attained to make a detail analysis on how the object reacts against shock wave and bubble. Experimental results show that there exits a low-pressure fluid zone below the girder due to bubble pulse in near field. The low-pressure area makes the girder undergo a vertical bending moment and possibly suffer an overall bending damage. With the increase of stand-off, the relevance of explosion energy and damage effect gradually increases. If stand-off is close to the maximum bubble radius, the bubble will exert a maximum damage effect on the structure.