Research Progress of Ultrasonic Testing and Evaluation Technology for Fiber Buckling Defects of Laminated Structure of Advanced Resin Matrix Composites
XU Guirong 1 , MA Tengfei 2 , LI Yang 3 , XIAO Peng 4 , ZHOU Zhenggan 2
1. AVIC Harbin Aircraft Industry Group Co., Ltd., Harbin 150066, China;
2. Beihang University, Beijing 100191, China;
3. Ningbo Institute of Technology, Beihang University, Ningbo 315800, China;
4. COMAC Composites Center, Shanghai 201324, China
Abstract：In recent years, to meet the new requirements of nondestructive testing and evaluation of fiber buckling in aircraft industry, many researchers have carried out NDT&E research on fiber buckling defects using ultrasonic. Unlike typical defects such as delamination, porosity and inclusion, fiber buckling defects resulting in less acoustic impedance mismatch to reflect the transmitted ultrasonic wave, it is difficult to characterize fiber buckling defects by ultrasonic A-scan signal. The main research progress of ultrasonic nondestructive testing and evaluation technology of fiber buckling defects has been introduced from three aspects including detection principle, ultrasonic transducer parameter selection and ultrasonic data post-processing method. In the meantime, the shortcomings of current research and its future development trends have also been discussed. In terms of detection principle, the structure characteristics of CFRP laminates, the different ultrasonic responses caused by the local structural changes caused by the out-of-plane/in-plane fiber buckling defects, and the detection scheme of the fiber buckling defects by using different ultrasonic response characteristics are introduced. In the aspect of parameter selection of ultrasonic transducer, the selection criteria of using half-wave resonance to maximize the interlayer echo energy are introduced. In the aspect of ultrasonic echo data post-processing, the methods are presented that the instantaneous phase method and average scattering coefficient matrix are used to detect the out-of-plane fiber buckling defects, the angle spectrum distribution and local image operator are used to detect the in-plane fiber buckling, and the three-dimensional direction of the carbon fiber is measured by the image structure tensor. Finally, the shortcomings of the current research work and the future development trend are analyzed in the aspects of acoustic mechanism, detection ability, types of detectable defects and types of inspected structural parts.
2021, 
