储罐底板声源辨识及定位方法研究

Research on acoustic source identification and positioning method of simulated tank bottom

储罐底板腐蚀是多声源问题,在不同位置的腐蚀源可能同时发射应力波。这些声源信号有时会重叠被传感器接收,从而影响定位的可靠性。为此本文基于平面声发射源能量定位方法的基本理论,进行了模拟储罐底板定位实验,提出了能量定位系数的修正方法。通过对实验数据分析,发现快速独立分量分析(Fast ICA)方法可以将同种声源混合信号进行有效分离,并且基本保持原有波形特征,相干系数法可以实现对分离后的同源信号进行聚类,进而应用改进能量定位方法对声发射源进行定位,从而对声源辨识,判断事件集中度提供依据。

The acoustic emission due to tank bottom corrosion is characteristic of multiple sources, i.e. the sources of corrosion in different locations may emit stress waves at the same time. The signals of these acoustic sources might be overlapped and received by various channels, and thus the reliability of source location would be affected. Based on the energy planar location theory of acoustic emission source, the positioning experiment of simulated tank bottom was conducted, and coefficient correction method of energy positioning was proposed. At the same time, through the analysis of experiment data, it is found that fast independent component analysis could separate the mixed signals of the same acoustic source, and keep the original waveform character to some degree. Moreover, correlation coefficient method can cluster the homologous signal after separation, and then improved energy positioning method could be applied to locate acoustic emission source, thus the identification of acoustic source and the judgment of events concentration can be directed.