Flexural properties of glass and carbon fiber reinforced epoxy hybrid composites

A study on the flexural properties of hybrid glass and carbon fiber reinforced epoxy composites is presented in this article. Three combinations of the carbon and glass fibers, 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 fibers 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 behavior was also simulated using finite element analysis, and the flexural modulus, flexural strength and strain to failure were calculated. Both the experiments and finite element analysis suggest flexural modulus decreases with increasing percentage of glass fibers. Positive hybrid effects exist by substituting carbon fibers with glass fibers on the compressive surface.