【摘要】 针对某水下目标的抗水下爆炸试验数据,基于短时Fourier变换、小波包变换进行时频分析比较研究,得到水下爆炸作用下水下目标振动信号的时频分布和能量分布规律。结果表明,短时Fourier变换使用的窗函数固定,分辨率单一,其分析结果只能大致反映信号能量随时间的变化;小波包具有更好的时频特性,可以提取出水下爆炸下冲击波、滞后流和二次压力波三个不同时段的信号进行能量和频率分析,并由此可确定不同时段对目标毁伤的影响。更多还原

【Abstract】 The experiment data of a underwater target subjected to underwater explosion was analyzed in time and frequency domain by means of short time Fourier transform and wavelet packet transform. By using these signals, the time-frequency distributions and the energy distributions of blasting frequency bands were obtained. The analyzed results from short time Fourier transform with fixed window function and single resolving power could only reflect how the signal energy varied with time approximately and results from wavelet packet transform had better features of time-frequency, which can obtain the shock wave signal, the afterflow signal and the second pressure pulse to analyze its energy and frequency component, and the respective influence of the signal in different period on the target could be assessed.更多还原