Evaluation Of Interface Fracture Energy For Single-Fibre Composites

Raman and luminescence spectroscopy have been used for the first time to determine the interface fracture energy for single-fibre composites. By using the measured fibre stress distributions in single-fibre fragmentation composite specimens and a simple energy-balance scheme, the energy for the initiation of interfacial debonding has been estimated for carbon (T50) and alpha-alumina (PRD-166 and Nextel 610) fibres embedded in epoxy resins. It has been found that the interface fracture energy shows good sensitivity to changes in the level of fibre/matrix adhesion clue to surface treatment and sizing of the fibres. It is also found that the values of interface fracture energy correlate well with measured values of interfacial shear strength determined for the same fibre/matrix systems. (C) 1998 Elsevier Science Ltd. All rights reserved.