Comparison of mechanical properties of glass fiber/vinyl ester and carbon fiber/vinyl ester composites

Glass and carbon fiber composite laminates were made by vacuum infusion of vinyl ester resin into biaxially knitted glass and carbon fiber fabrics. The strengths of the glass and carbon fiber specimens in tension, compression, open hole tension, open hole compression, transverse tension, indentation and ballistic impact were compared. The carbon fiber laminates proved mechanically superior under loading conditions where the strength is mainly fiber dominated, i.e. under tensile loading and indentation. The ratio of the carbon fiber laminate strength to the glass fiber laminate strength, for laminates of equal thickness, was similar to the ratio of the fiber tensile strengths. The glass fiber laminates were equally strong or stronger under loading conditions where the strength is mainly resin dominated, i.e. compressive loading and ballistic impact. In the carbon fiber specimens, the failure was in general more localized and the strengths had more scatter than in the glass fiber specimens.