Effects of moisture absorption on the dynamic interlaminar fracture toughness of carbon/epoxy composites

Effects of moisture absorption on the dynamic mode II interlaminar fracture behavior of two different kinds of carbon/epoxy composites at a low impact rate of 0.9 m/s were studied. ENF specimens were preconditioned under thre e different environmental conditions, that is, dry, 80 degrees C-90% RH and 80 degrees C-wet. Mode II interlaminar fracture toughnesses, G(IIC), of th e composites were then evaluated under quasi-static and dynamic loading. Th e results showed that moisture absorption had an influence on the G(IIC) va lues of the composites. The experimental results also exhibited that the im pact loading condition tended to decrease the G(IIC) values. Scanning elect ron micrography was also performed to characterize the micromechanisms of m ode II interlaminar fracture. Effects of moisture absorption on the mode II interlaminar fracture behavior were then discussed on the basis of the res ults of the interlaminar fracture testing and microscopic studies.