A ultrasonic vibrative cleaning method is introduced and it′s cleaning mechanism is analyzed theoretically, some points for attention in choosing ultrasonicparameter are expounded.
The wavelet coefficient of the feature band was regarded as the feature parameter of the Acousto Ultrasonic signal and it can distinguish defects from the adhesively bonded joints.
以此特征频带的小波变换系数作为声-超声信号特征参数，可分辨出胶接区域的缺陷信号。
3
We reported the main progress made in China in recent years of the study of ultrasonic tissue characterization-propagation velocity, attenuation, scattering and nonlinearity parameter, etc.