空气耦合超声斜入射法检测固体火箭发动机脱粘缺陷及成像技术研究  

Research on imaging technology of solid rocket motor debonding defect detection based on air-coupled ultrasonic oblique incidence method

作　　者：李博俊 李剑 艾春安 黄留春 吴超 LI Bojun;LI Jian;AI Chun’an;HUANG Liuchun;WU Chao(Rocket Force Engineering University,Xi’an 710025,China)

机构地区：[1]火箭军工程大学,陕西西安710025

出　　处：《中国测试》2023年第7期139-147,共9页China Measurement & Test

基　　金：国防重点实验室基金项目(61427010203192701001)。

摘　　要：为实现固体火箭发动机复合材料壳体粘接结构的非接触在役检测,该文采用空气耦合超声斜入射反射法进行研究。构建空气耦合超声斜入射检测系统,根据理论和实验确定有效的入射角范围并得出最佳入射角度,使用不同频率的探头在最佳入射角度下进行斜入射横波法反射法C扫描成像,最后用图像处理方法对缺陷进行定量表征,并与穿透法C扫描结果进行对比。结果表明:当遇到缺陷时,信号幅值会增大;两种检测频率下,12°为最佳入射角,且频率越大,信号的衰减越大;使用420 kHz探头检测时获得的C扫描图像质量高于250 kHz。通过混合滤波、改进的区域生长图像分割、Canny算子边缘提取以及形态学平滑处理和细化等方法,有效提取缺陷边缘,可实现缺陷的定量表征,420 kHz探头定量精度明显高于250 kHz,且缺陷尺寸越大,该方法结果与穿透法结果越吻合。In order to realize the non-contact in-service detection of the bonding structure of solid rocket motor composite shell,the air-coupled ultrasonic oblique incident reflection method is used in this paper.Building air coupling ultrasonic oblique incident detection system,according to the theory and experiment to determine the effective angle of incidence and obtain optimal incident angle,using different frequency probe under the optimal incident angle oblique incidence shear wave reflection method C scan imaging,finally using image processing method to quantitative characterization of defects,and comparing with the results through the method of C scan.The results show that the signal amplitude increases when the defect is encountered.Under the two detection frequencies,12°is the best incident angle,and the higher the frequency,the greater the signal attenuation.The C-scan image quality obtained by using the 420 kHz probe is higher than 250 kHz.Through hybrid filtering,improved region growth image segmentation,Canny operator edge extraction,morphological smoothing and refinement methods,the defect edges were effectively extracted,and the quantitative characterization of defects was realized.The quantitative accuracy of 420 kHz probe was significantly higher than that of 250 kHz,and the larger the defect size was,the more consistent the results of this method were with those of the penetration method.

关 键 词：固体火箭发动机 空气耦合超声 斜入射法 横波 缺陷成像 

分 类 号：TB553[理学—物理] TB9[理学—声学]