Measurement of interfacial shear strength of carbon fibre/epoxy composites using a single fibre pull-out test

Single fiber pull-out tests were conducted for G34-700/Araldite-F, T700S/Araldite-F and T800H/Araldite-F model composites using an improved experimental set-up to evaluate the interfacial shear strength (IFSS). The modified method made it possible to reduce the formation of resin meniscus and to accurately define the embedded fibre length, and it also provided a practical approach to conveniently estimate the IFSS for comparison of the fibre-matrix adhesion between different composite systems or different fibre surface conditions. A strong interfacial adhesion and unstable debonding process without detectable friction stages were found for all types of model composites with fibres being chemically treated/sized or sizing being removed. The electrochemical oxidation treatment and sizing on the carbon fibres noticeably increase the IFSS of the composites.