;近距水下爆炸作用下箱形梁模型中垂破坏试验研究

利用大型室内爆炸筒对两个水面箱形梁模型进行近距水下爆炸试验，用高速摄影记录模型在气泡作用下的运动变形及中垂破坏过程。试验发现，气泡收缩时，近距船底边界阻碍流体运动并在气泡上方产生空化区域，增加了气泡负压的作用强度和作用时间，是模型发生中垂破坏的主要原因。同时，当模型垂向振动频率与气泡脉动频率接近时，冲击波引起的模型垂向振动与气泡负压作用叠加，增加了模型发生中垂破坏的可能。试验研究了爆距的改变对气泡负压作用以及冲击垂向振动幅值的影响。试验结果表明，只有当爆距小于2倍气泡最大半径时，近距边界效应不可忽略。

Sagging damage test of box-beam models subjected to close range underwater explosion

A close range underwater explosion test on two box-beam models was made in blast cube.High speed photography was applied to capture the sagging damage process of the model subjected to bubble movement.Experimental results showed that when the bubble shrinks,the close range hull bottom boundary blocks fluid movement and forms cavities area up the bubble,enhances the bubble's negative pressure effects including intensity and time duration,so the close range boundary effect is the main cause of model's sagging...