Defect imaging in carbon fiber composites by acoustic shearography

Abstract

Carbon fiber reinforced polymer (CFRP) composites are increasingly used in aerospace, automobile, marine and power industries due to its good mechanical strength and low material density. The defect detection in CFRP has been challenging because of their complex material configuration and various types of defects. In this paper, we reported the use of acoustic shearography imaging for defect detection in carbon fiber composite materials. CFRP specimens with different levels of defects were prepared by open-hole compression tests according to ASTM standard. These specimens were subsequently tested with acoustic shearography imaging method. It is found that acoustic shearography can successfully image various defects efficiently. By synchronizing the stroboscopic laser with the ultrasonic wave frequency, the defect imaging quality can be significantly improved. Comparison with X-ray computed tomography results shows that acoustic shearography can provide sufficiently good defect imaging results with significantly reduced imaging time.