INTERFACIAL STUDIES ON MODEL COMPOSITES BY LASER RAMAN-SPECTROSCOPY

A new technique for the determination of fibre strain in composites has been developed over the years. The strain-sensitive property of high-performance fibres is a vibrational frequency which can be measured by laser Raman spectroscopy (LRS). The application of this technique for performing interfacial studies on model short- and long-fibre composites will be reviewed in this paper. By subjecting these composites to various degrees of mechanical deformation a number of parameters, such as the transfer length, the stress transfer efficiency and the initiation of fibre debonding or matrix yielding, can be assessed. Finally, by simply balancing the tensile and the shear forces acting along the interface, the interfacial shear stress distribution at each level of applied load can be obtained.