Mode I fracture characterization of a hybrid cork and carbon–epoxy laminate

In this work fracture characterization under mode I loading of a hybrid laminate composed by a unidirectional carbon–epoxy composite and cork was performed using the Double Cantilever Beam test. An equivalent crack length procedure based on specimen compliance and Timoshenko beam theory applied to the composed beam was adopted to evaluate the fracture energy. The procedure revealed to be quite effective and it was validated numerically by means of finite element analysis including cohesive zone modelling. The analysis of the experimental results has shown that an increase of 32% of mode I toughness relative to monolithic carbon–epoxy laminate was obtained, which proves that hybridization using cork results in a quite effective procedure to increase interlaminar toughness of composite laminates.