부산대학교 도서관

Nondestructive evaluation (NDE) technology has garnered interest as an inspection tool in various industries. In this study, ultrasonic technology was applied to the defect monitoring of carbon fiber reinforced plastic (CFRP) composite materials. By using ultrasonic technology, major ultrasonic reflection signals were observed in sequential order for defect evaluation in unidirectional composites. As ultrasonic waves propagate through the unidirectional CFRP composite, mode conversion, attenuation, and scattering results in a relative decrease in the peak-to-peak amplitude of the reflected ultrasonic signals, indicating the presence of defects. In the pitch-catch mode, three to four ultrasonic reflection signals were observed, and by implementing the beam profile of the reflected signals, we confirmed that the signal-to-noise ratio can be utilized as a key parameter for NDE by providing an effective scanning range of ultrasonic amplitudes.