해수 열화 및 원공 손상 CF/Aramid 복합재의 패치 부착이 굽힘거동에 미치는 영향

• Published in: 한국안전학회지 Vol. 38; no. 3; pp. 20 - 26
• Main Authors: 권우덕, 권오헌, 윤유성, Woo Deok Kwon, Oh Heon Kwon, Yu Seong Yun
• Format: Journal Article
• Language: Korean
• Published: 한국안전학회 01.06.2023
• Subjects: 안전공학; hole; flexural test; repaired patch; seawater aging; CF/Aramid composite; acoustic emission
• ISSN: 1738-3803; 2383-9953

Fiber-reinforced composite materials with carbon, glass, and aramid fibers are widely applied to industrial field structures due to their excellent properties. However, carbon fibers are vulnerable to external impacts, whereas aramid fibers degrade when exposed to water. This study evaluated carbon/aramid fiber composites degraded and damaged by high-temperature saline environments using acoustic emission (AE). The test specimen was molded using an autoclave and immersed in seawater at 70 ℃ for 224 days. In order to imitate the damage, a 3-mm-diameter hole was drilled using a diamond drill. Additionally, the specimen with the perforation was repaired by patch attachment processing. Three-point bending was used to conduct the flexural experiment, and an AE sensor with a 150-kHz resonance frequency was attached to evaluate the damage and the effect of patch attachment. AE accumulative counts obtained at the maximum load were 69.2, 67.1, and 91.2 for a high-temperature seawater deteriorated condition, a hole specimen, and a repaired patch specimen, respectively. Furthermore, the maximum amplitude of AE was detected at low values of 28 dB, 31.3 dB, and 30.3 dB.