CAJ | 학술논문

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。
침대다층복합재료심층계면탈점검측중회파신호신조비저화난이분변적난제，장소파변환인입도회파신호적초성파검측중래；분석료소파변환급다분변솔분석적이론의거，침대회파신호수선진행소파거조，연후제취소파변환후각빈단적신호능량작위특정，위결함분석급식별제공의거；실험결과표명：소파역치거조산법적개진방안명현요비단순적경역치화연역치방법강조효과호，신호분석방법병가유효제취신호적특정，병장결함식별、정위。
Aiming at the problem of low signal-to-noise and serious overlap of the echo signals from multi-layer composite materials deep-seated interface non-felt detection,the wavelet transform method was intro-duced to ultrasonic detection of echo signals.Theory of wavelet transform and multi-resolution analysis was analyzed,aiming at echo signals,wavelet de-noising firstly,than the energy which were extracted from de-tection 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 de-fects.