Synergistic fibre strengthening in hybrid composites

Abstract

The theoretical stress-strain behaviour of a three component hybrid composite consisting of a brittle fibre and a “matrix” composed of a binder and less brittle fibre is described, and the conditions required for a synergistic strengthening of the brittle fibres are compared for the limiting assumptions of a frictional and elastic bond. The theory is tested using a dispersed type I carbon-glass-epoxy hybrid and it is shown that increases in effective fibre strength of around 100% can be obtained. Finally, the economic and structural advantages of using a hybrid in place of a conventional carbon composite of the same modulus are discussed.