水下爆炸船体结构壁压信号时频特征分析

Analysis of time-frequency characteristics of wall pressure signals of hull structure subjected to underwater explosion

为了研究水下爆炸条件下船体结构壁压信号时频特征,基于某船体结构模型水下爆炸实验壁压数据,利用小波变换良好的时频局部化性质,对壁压信号进行时频特征分析,得到壁压信号在不同频带上的压力时程曲线和能量分布.结果表明,利用小波变换可以方便地获得壁压信号强度、频率和持续时间等时频细节信息.能量统计表明,壁压信号频带分布很广,超过80%的能量主要集中在20kHz以下,5kHz以下频带能量最大.

With a view to obtaining the time-frequency characteristics of wall pressure signals of hull structure subj ected to underwater explosion,based on the experimental wall pressure data of a hull structure model subj ected to underwater explosion,the time-frequency characteristics of the wall pressure signals were studied by means of wavelet transform characterized with good time-frequency localization. By using these wall pressure signals, the pressure-time curves and the energy distributions in different frequency bands were obtained.The experimental results show that it is easy to get the time-frequency information details of the wall pressure signals by the wavelet transform, such as intensity,frequency and duration,etc..Energy statistics show that frequency bands of the wall pressure signals have a wide distribution,more than 80% of the energy of the wall pressure signals is mainly concentrated in the area of less than 20 kHz and the highest level of energy is below the frequency of 5 kHz.