Interfacial bonding and thermal expansion of fibre-reinforced composites

The present work examines the effect that the fibre-matrix bond strength has on longitudinal and transverse thermal expansivities of unidirectional glass fibre and carbon fibre-reinforced epoxies. It is shown that the weakening of the interfacial bond results in an increase of the longitudinal coefficient of thermal expansion, and a decrease of the transverse one. The results are explained in terms of the reinforcement efficiency factor, according to a theory proposed elsewhere.