水下爆炸载荷下舰船双层底部结构的毁伤特性

To study the damage characteristics of a ship’s double bottom structure subjected to underwater explosion. Experiments on the interaction between the electric spark bubble and the ship’s double bottom structure with a hole are carried out. The pulsation characteristics of the bubble are captured by a high-speed camera, and the experiment is simulated by LS-DYNA to verify the effectiveness of the numerical model. Then, the finite element model of the full-scale cabin is established. By changing the explosion distance and water level between the double bottoms and designing 15 simulation scenarios, the damage characteristics of the double bottom structure subjected to shock wave and bubble loads are analyzed. The results show that: when the explosion distance is small, the outer bottom is broken, and the expansion of the "inner bubble" intensifies the tearing of the outer bottom and causes the plastic deformation of the inner bottom; when the explosion distance is large, the outer bottom only deforms and contacts with the inner bottom, driving the deformation of the inner bottom at the same time; when the water level between the two bottoms is low, the shock wave load attenuation is large with a small damage to the inner bottom, and the expansion of the "inner bubble" plays a major role in the deformation of the inner bottom; when the water level between the two bottoms is high, the shock wave load attenuation is small, the shock wave and bubble pulsation loads propagate through the water medium and act on the inner bottom, whose combined action causes its deformation.