In recent years

 to meet the new requirements of nondestructive testing and evaluation of fiber buckling in aircraft industry

 many researchers have carried out NDTE 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.