Ultrasonic attenuation as a measure of void content in carbon-fibre reinforced plastics

Abstract The authors describe a technique for determination of the void content of carbon-fibre reinforced plastics (cfrp) from its effect on the attenuation of ultrasound. They describe briefly the fabrication of cfrp laminates and the defects which cause an increase in ultrasonic attentuation. The article concentrates on the effect of voids and shows that void content and ultrasonic attenuation are directly related. This attenuation increases with frequency. The authors establish a close correlation between ultrasonic attenuation and interlaminar shear strength. Finally, the authors describe difficulties in the application of the technique and suggest where further investigation is needed.