基于Hilbert-Huang变换的船舶结构冲击响应研究

针对水下爆炸时船舶结构遭受的冲击响应信号具有非线性非平稳的特点,提出将Hilbert-Huang变换用于船舶结构冲击响应信号处理.Hilbert-Huang变换是基于经验模态分解(EMD)和Hilbert谱的一种信号处理方法,用EMD分解把时间序列信号分解成不同特征时间尺度的固有模态函数(IMF),然后对IMF分量进行Hilbert变换,从本质上分析船舶结构冲击响应信号的组成成分及特点.与FFT变换和小波变换相比,Hilbert-Huang变换体现出自适应性和先进性,可以有效提取船舶冲击响应信号的时频特征,揭示船舶结构自身的动态特性对冲击响应的影响.

Research on Impulse Response Signal of Ship Structures Based on Hilbert-Huang Transform

Since impulse response signals of ship structures subjected to underwater explosion are characteristics of nonlinear and non-stationary, a new method of Hilbert-Huang transform (HHT) is proposed to analyze this impulse response signals of ship structures. The HHT is a novel signal processing method based on Empirical Mode Decomposition (EMD) and Hilbert transform. The EMD decomposes the original times series data in several Intrinsic Mode Functions (IMF), then the characteristics of the impulse response signals of ship structures are analyzed essentially by using Hilbert transform for every IMF. Comparing with traditional FFT transform and wavelet transform in analytical process, the HHT is found to be self-adaptive and superior in performance, and can effectively extract time-frequency characteristics of impulse response signals of ship structures. The influence of the intrinsic properties of ship structures on shock response is also discussed.