Composites Science and Technology vol:54 issue:2 pages:133-145
The bond between a fibre and the matrix is very important for the mechanical behaviour of CFRP. The quality of the fibre/matrix interface will influence the initiation and development of damage. This is certainly true for interlaminar fracture toughness. The present study is focused in the influence of the interface properties on the fracture toughness of CFRP. Carbon fibres with four different wet oxidative surface treatment levels have been investigated The fibres were embedded in a thermoset resin and in a thermoplastic system. Mode I, mode II and mixed-mode tests were performed to determine critical strain-energy release rates. Results show an important increase in the fracture toughness initiation value with increasing fibre surface treatment level. For tests dominated by mode I loading, however, the propagation value can reach a maximum at intermediate treatment levels as a consequence of fibre bridging effects.