基于“能量-缺陷”的金属基复合材料缺陷信号特征提取

Extraction of Defect Features of Metal Matrix Composite Based on 'Energy-Defect'

将小波包多分辨率分析与能量谱相结合,提出了一种复合材料缺陷特征提取的方法-“能量-缺陷”法;首先将检测到的复合材料缺陷超声信号进行3层小波包分解,在通频带范围内得到分布在不同频段内的分解序列,进而分别求出各频段的总能量,选取最能反映缺陷特征的参数-“能量特征向量”作为特征参数,进行缺陷的识别;以金属基复合材料超声信号为例,运用“能量-缺陷”法进行了缺陷信号特征提取,试验表明此方法是一种行之有效的新方法,为复合材料缺陷检测与识别开拓了新的思路。

A method of extraction of defect features of metal matrix composite by combining multi-resolution signal decomposition of the wavelet packet with energy spectrum in suggested. The method is called＇energy-defect＇, Firstly, the defect signal is decomposed by the three-layer wavelet packet, and a set of decomposition sequences distribution in different frequency intervals are obtained in frequency domain, then respectively calculate the total energy of every frequency interval. Finally, the energy characteristic vector, which is the best parameter that reflects the defect features, is chosen as characteristic parameter for defect recognition. As a example, the defect signal of metal matrix composite is processed with the method and its features are extracted by using the method of ＇energy-defect＇ and it is shown that the method is effective for extraction and recognition. The method develops a new direction for extraction and recognition of the defect of composite material