小波变换在多层复合材料的超声波检测中的应用  

Application of Wavelet Transform in Ultrasonic Detect in Multilayer Composite Materials

作　　者：朱建峰[1] 郭伟剑[1] 刘俊邦[1] 华鹏翔 

机构地区：[1]武汉军械士官学校,武汉430075

出　　处：《四川兵工学报》2014年第7期67-70,共4页Journal of Sichuan Ordnance

基　　金：国家自然科学基金项目(50805145)

摘　　要：针对多层复合材料深层界面脱粘检测中回波信号信噪比低和难以分辨的难题,将小波变换引入到回波信号的超声波检测中来;分析了小波变换及多分辨率分析的理论依据,针对回波信号首先进行小波去噪,然后提取小波变换后各频段的信号能量作为特征,为缺陷分析及识别提供依据;实验结果表明:小波阈值去噪算法的改进方案明显要比单纯的硬阈值和软阈值方法降噪效果好,信号分析方法并可有效提取信号的特征,并将缺陷识别、定位。Aiming at the problem of low signal-to-noise and serious overlap of the echo signals from multilayer composite materials deep-seated interface non-felt detection,the wavelet transform method was introduced to ultrasonic detection of echo signals.Theory of wavelet transform and multi-resolution analysis was analyzed,aiming at echo signals,wavelet denoising firstly,than the energy which were extracted from detection echoes in different frequency range after wavelet transform.The results show that the improved method of wavelet de-noising threshold is better than traditional threshold strategy in de-noising,the signals analysis method is effective for the extraction of signal information and it also can identify and locate defects.

关 键 词：多层复合材料 小波变换 超声波检测 阈值去噪 特征提取 

分 类 号：TP274.2[自动化与计算机技术—检测技术与自动化装置]