近场脉动气泡作用下船体梁模型动响应试验研究

Experimental study on dynamic response of a ship-like model subjected to near field underwater explosion bubbles

水中兵器在舰船附近爆炸时,爆炸气泡对船体结构的整体毁伤作用不能忽视.将炸药置于船体梁模型中部正下方爆炸,通过改变爆距来研究船体模型在近场脉动气泡作用下的动态响应特性.利用高速摄影技术观察模型在气泡作用下的运动过程,结合应变和加速度测量数据,定量分析了模型的总体振动响应.试验发现:近场作用下,气泡脉动压力对结构的冲击作用明显;在大气压和气泡内压力作用下,试验模型受到向下的分布载荷,被叠加一中垂弯矩,爆距越小,此中垂弯矩越大.

When underwater anti-warship weapons explode near warship, explosion bubbles impose a significant impact on the whole hull. In order to understand how the distance of explosion bubbles affect a hull, an experimental study was carried out using a small-scale ship-like model. The model was floating in a tank and subjected to explosions near the mid-span of the model, thus creating bubble effects. The dynamic response of the hull was investigated by changing the distance of the explosions. In tests, high-speed photography was applied to capture the whole process of the response to bubbles. Simultaneously, data of strain and acceleration were recorded to allow a quantitative analysis. Experimental results showed that, bubble impulsion has a remarkable impact on objects which the bubbles are located nearby. Due to difference between atmospheric pressure and inner bubble pressure, the model is subjected to a downward distributed load, equivalent to a bending moment at mid-span. The shorter the explosion distance, the greater the mid-span bending moment.