Tensile properties of multilayered biaxial weft knitted fabric reinforced composite material

Abstract

The multilayered biaxial weft knitted (MBWK) fabric made of E-glass fibres and stitched with polyester yarns, which is a kind of non-crimp fabrics, has been impregnated with epoxy via resin film infusion technique to manufacture the composite plates. The tensile properties of the MBWK fabric reinforced composite are studied with the multidirectional tensile testing. The classical lamination theory is applied to evaluate both the tensile modulus and Poisson's ratio, which shows good agreements with the experimental results. Failure analyses are also available by means of sample debris examination to identify the failure modes and the scanning electron microscope to reveal the microscopic mechanism. Predictions of the tensile properties provide a way to estimate the mechanical behaviours of the MBWK composite structures. Elongation at break is independent of the testing directions, which can be used as the failure criterion of the composite.