Abstract
In this study, effects of water absorption and freezing on mode I interlaminar fracture toughness of CFRP were investigated. Water absorption test was conducted at 90℃ for 24, 100, 250 and 500 hours. After water absorption, the specimens were kept in the -15℃ environment for 24 hours. Static three-point bending and double cantilever beam (DCB) tests were conducted after water absorption and freezing. As a result, the water absorption rate at 500 hour was 1.5%. Bending strength and mode I interlaminar fracture toughness G_<IC> were decreased with increasing water absorption time. Bending modulus of CFRP did not change after water absorption and freezing. And bending strength and mode I interlaminar fracture toughness G_<IC> in frozen CFRP were lower than that of water absorbed CFRP. These result implied that interfacial adhesion of CFRP was decreased by water absorption.