The object of this study is to investigate the interlaminar fracture characteristics of graphite/epoxy composites containing with the interlaminar polyester film. The interlaminar fracture toughness of Gr/Ep composites (Toray prepreg type p-3060, T300 graphite/\#3601 epoxy) were measured by the Arcan test specimens under the opening and shearing mode conditions. The quadratic relation for the mixed mode behavior was compared to the experimental data.
The fracture toughness for Toray p-3060 were shown to be 0.711MPa$\surd$m (647 psi$\surd$in) and 12.8MPa$\surd$m (11600psi$\surd$in) for the opening and shearing modes, respectively. The fracture toughness of the composites with the film was 1.88 times as much as that of the composites without the film for the opening mode. And the test results showed general agreement with the mixed mode failure criterion.
