水下爆炸压力时频分布的小波包分析

Analysis of time-frequency distribution of underwater explosion pressure through wavelet packet transform

为了对舰船结构和设备的冲击环境进行研究,提出了基于小波包分析的水下爆炸压力时频分析方法.研究了短时非平稳水下爆炸压力实验测试信号的时频分布和能量分布规律,从水下爆炸压力时域信号中提取出冲击波,首次和二次气泡脉动压力信号,分析了它们在不同频带的能量分布规律.结果表明,基于小波包的时频分析方法可以提取水下爆炸压力不同时段的信号进行能量和频率分析,水下爆炸压力中以低频成分为主的气泡脉动压力产生的能量接近总能量的一半,是使安装频率为数十赫兹的舰船设备产生冲击振动的主要能源.

In order to study underwater shock environment of ship structure and equipment, a time-frequency distribution analysis method for underwater explosion pressure through wavelet packet transform is proposed. The experimental results of underwater explosion pressure signal are presented, and the time-frequency distributions and energy distributions are also calculated. The shock wave signal, the first air bubble pressure signal, and the second air bubble pressure signal are gotten from underwater explosion pressure signal, and their energy distributions in different frequency bands are also analyzed. The results show that the method of time-frequency distribution analysis through wavelet packet transform can obtain the signal in different period to analyze its energy and frequency component, and the air bubble pressure made up of low frequency component contains nearly 50 percent energy. It is an important energy-source for shock and vibration of ship equipment that has mounting frequency of several decade hertz.