Ultrasonic nondestructive evaluation of graphite epoxy composite laminates

Quantitative ultrasonic techniques are summarized with applications to the measurement of frequency-dependent attenuation and backscatter and to the NDE of composite laminates. Results are listed for the ultrasonic NDE of graphite-epoxy composite laminates including impact and fatigue damage as well as porosity. The methods reviewed include transmission measurements of attenuation, reconstructive tomography based on attenuation, estimating attenuation from backscattered ultrasound, and backscatter approaches. Phase-sensitive and -insensitive detection techniques are mentioned such as phase cancellation at piezoelectric receiving transducers and acoustoelectric effects. The techniques permit the NDE of the parameters listed in inhomogeneous media and provide both images from the transmission mode and in the reflection mode.