Experimental comparison of interlaminar toughness of carbon/peek, carbon/epoxy and glass/epoxy composites

Comparative studies of interlaminar toughness G_Ic and G_IIc of carbon/epoxy, carbon/PEEK and unidirectional glass fabric/epoxy and 2/2 twill fabric/epoxy have been carried out with the use of the Double Cantilever Beam and End Notched Flexure methods. Carbon fiber reinforced composites were made from unidirectional prepregs. The glass reinforced composites were impregnated with the use of wet lay up method. The obtained results suggest that the composites made with prepregs display more consistent mechanical properties than those reinforced with glass fabric impregnated with epoxy resin. On the other hand, the interlaminar toughness of the latter was almost three times higher than those of carbon/epoxy. Unfortunately, due to insufficient number of specimens a meaningful statistical analysis of the results could not be carried out. Application of various data reduction methods have shown that the results they produce are practically the same with the exception of the area method which produces inconsistent numbers.