局域波法在海洋平台结构声发射信号监测中的应用  

Local wave applied to detect and characterize the offshore structure acoustic emission signals

作　　者：林丽[1] 赵德有[1] 

机构地区：[1]大连理工大学船舶工程系,大连116023

出　　处：《振动与冲击》2009年第6期71-74,共4页Journal of Vibration and Shock

基　　金：国家自然科学基金资助(No.50479060)

摘　　要：将局域波用于分析导管架海洋平台模型的声发射信号,以获得声发射信号的时频特征和频率能量分布。通过局域波分解将声发射信号分解为一组基本模式分量(IMF),对每一个IMF分量进行希尔伯特变换获得信号能量随时间频率的变化;由局域波时频谱得到边际谱,反映声发射信号的能量频率分布特征。通过分析导管架海洋平台模型模拟声发射信号,获得了特征,运用局域波分析方法监测到导管架海洋平台预制裂纹声发射信号的出现。因此,局域波法可以用于分析导管架海洋平台的声发射信号,在声发射信号处理领域将会有广阔的应用前景。The possibility was shown of using local-wave to analyze the time-frequency feature of the acoustic emission signals produced by the crack in the offshore structure model. In the investigation, a local wave decomposition technique was used, allowing time series of acoustic emission signal be decomposed into a small number of intrinsic mode function components (IMF). With the Hilbert transformation process, IMF can be translated into an expression called Hilbert spectra, which exhibits the amplitude-frequency-time distribution of the data. The marginal spectra, which describe the energy-frequency distribution of the data, were obtained by integrating the Hilbert spectra over time. On the basis of local-wave analysis, the appcarance of acoustic emission was monitored and the characteristics of the acoustic emission signals of crack in the offshore structure were obtained. The experimental results show that the proposed approach is able to effectively capture the significant information reflecting the acoustic emission in the offshore structure, and thus has good potential in the field of acoustic emission signal feature extraction.

关 键 词：局域波 声发射 信号处理 海洋平台 

分 类 号：TB52[理学—物理]