水下近距爆炸作用下船体梁的动态响应特性

为研究舰船在水下近距爆炸作用下的结构响应及损伤模式,以相似准则为基础,设计了船体梁模型,选用4种不同能量结构的炸药,将其置于模型中部正下方爆炸,通过改变药量和爆距,实验研究了船体梁在近距爆炸作用下的动态响应特性。利用高速摄影技术观察了模型的整个运动过程,结合实验数据定量分析了结构的应变和加速度响应特性,比较了冲击波和气泡脉动对结构的损伤特点。研究发现:近距爆炸气泡脉动会使结构下方形成一个低压流体区,该低压区的存在会使模型受到中垂弯矩作用,并可能使其发生中垂弯曲破坏;随着爆距的增大,爆炸能量与损伤效果之间的相关性变得明显;近距条件下,为了发挥爆炸气泡的最大破坏作用,爆距应该接近于最大气泡半径。

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.