CFRP层压板缺陷同侧空气耦合超声兰姆波特征成像检测研究

Study on Eigenvalue Imaging of CFRP Plate Defect using Air-coupled Ultrasonic Lamb Waves

为了实现飞机碳纤维增强复合材料(carbon fiber reinforced plastics,CFRP)层压板在役检测,采用同侧空气耦合超声兰姆波特征成像检测的方法对其缺陷进行检测。通过0.4 MHz空气耦合超声换能器在CFRP层压板同侧激励和接收A0模态兰姆波,以2个相互垂直的方向对缺陷部位进行D扫描。基于时域、频域、时频域的方法构建损伤指数,以此作为兰姆波特征成像的特征参量,通过对损伤指数进行全乘数据融合。研究结果证实该方法可以得到CFRP层压板缺陷的特征图像,实现缺陷的定位和定量。

To realize the aircraft carbon fiber reinforced composite (CFRP) plate in service inspection,the eigenvalue imaging based on air-couple ultrasonic lamb waves was used to detect the CFRP plates. The A0 mode lamb wave of the CFRP plate was generated and received by a pair of 0.4 MHz air-coupled ultrasonic transducers at same side. The two D-scans were used to obtain the lamb wave signals for eigenvalue imaging in mutually perpendicular directions. The damage indexs (DI) which represented the characteristic parameter of eigenvalue imaging were established by the method based on the time domain,frequency domain and time-frequency domain. By means of full multiplication fusing,the eigenvalue images were translated into the 2D image which could present the actual position and size of defect.