抄録
GFRP has excellent corrosion resistance, so it has been employed widely such as acid tanks and drainpipes. However, in rare cases, GFRP products are failed by the stress corrosion cracking(SCC)of fiber under acid environment. It is considered that SCC is caused by degradation of interfacial strength, except for thermal stress between fiber and resin, or expansion and reduction due to the water absorption and discharge. In this study, interlaminar fracture toughness of GFRP whose fiber surface was treated with different agent was measured. Specimens were set up in acid solution bath with various temperature or time. As a result of experiment, in the case of the specimen of weak interfacial strength, fracture toughness KI decreased with increase of time or temperature. On the other hand, KI hardly decreased in the case of the specimen of strong interfacial strength. However, results of crack growth rate of both specimens were scattered at 323 K. It is considered that this scattering is caused by the change of damage mechanism, e.g., from single crack to multiple cracks, from interlaminar delamination to interfacial debonding and occurring of fiber bridging.
