连续小波分析法在船体波激振动分析中的应用

Application of continuous wavelet transform in the investigation of ship hull springing

小波分析法特别适用于非平稳信号的分析和处理,针对船体波激振动的响应特征,简单介绍了连续小波变换的基本理论,提出了用Morlet小波分析船体响应的方法和步骤。重点运用小波分析分析了不规则遭遇波浪和船体弯矩响应的时频特征,并且与傅立叶变换结果进行了对比,研究了波浪与弯矩的相关特征,提出了波激振动产生原因的新的解释,有利于船舶响应的预报理论和结构设计方法的进一步发展。

Wavelet transform might be one of the most suitable approaches for the analysis of non-stationary signals. In this paper, the basic wavelet theory is first briefly introduced, then, considering the characteristics of wave loading responses of ships and different wavelet functions,the Morlet wavelet is selected and its application procedure is recommended for the analysis of recorded signals.The main effort of the application is to get the high-quality wavelet coefficient maps of the irregular waves and the corresponding bending moments of the ship.By comparing time-frequency features of these two signals,and comparing with the results of Fourier transformation,a new source of the ship hull springing in irregular waves is pointed out, which might be beneficial for the optimal design of ship structures.