两装药水下爆炸毁伤目标振动信号时频分析

针对某水下目标抗水下爆炸试验数据，研究两装药水爆炸下冲击波的相互作用及气泡脉动的相互作用现象，分析非平稳结构响应信号时频特征，分别提取前爆冲击波、后爆冲击波及前爆气泡脉动三个不同时段信号进行能量与频率分析，并由此确定不同时段对目标毁伤的影响。结果表明，后爆冲击波能量最大，前爆冲击波与后爆冲击波均处于较宽频率范围，主要作用在780 Hz以上，前爆气泡脉动能量主要作用在100～400 Hz内。与结构自振频率频段重合，因此前爆气泡脉动作用不可忽视。

Time-frequency analysis of vibration signal of underwater target by underwater explosion between two explosive charges

For the experiment data of a underwater target subjected to underwater explosion, the interaction of the shock wave and the bubble pulsation of the explosion in two charges were investigated and the time-frequency characteristic of the structure response being a non-stationary random process was analyzed. The first shock wave, the second and the first pressure pulse were extracted from the signal, and their energy distribution was analyzed and the respective influence of the signal in different period on the target could be assessed. Results from the investigation show that the main frequency components of the first shock wave and the second shock wave are higher than 780Hz which were in a wide frequency range and the second shock wave has the largest energy, and the main frequency components of the first pressure pulse was between 100Hz and 400Hz which may also cause the damage of the underwater structure because the natural frequency of the structure is also in this frequency band.