Flexural properties of glass and carbon fiber reinforced epoxy hybrid composites

A study on the flexural properties of hybrid glass and carbon fibre reinforced epoxy composites is presented in this paper. Three combinations of the carbon and glass fibres, i.e. S-2&T700S, S-2&TR30S and E&TR30S, were chosen to make hybrid composite specimens. Specimens were made by the hand lay-up process in an intra-ply configuration with varying degrees of glass fibres added to the surface of a carbon laminate. These specimens were then tested in the three point bend configuration in accordance with ASTM D790-07 at a span to depth ratio of 32. The failure modes were examined under an optical microscope, and it was found that the dominant failure mode was compressive failure. The flexural behaviour was also simulated using finite element analysis (FEA), and the flexural modulus, flexural strength and strain to failure were calculated. Both the experiments and FEA suggest flexural modulus decreases with increasing percentage of glass fibres. Positive hybrid effects exist by substituting carbon fibres with glass fibres on the compressive surface