THE EFFECT OF FIBER LENGTH ON FRACTURE-TOUGHNESS AND NOTCHED STRENGTHOF SHORT CARBON-FIBER EPOXY COMPOSITES

The effect of radius of curvature on the tensile notched strength of r andom short carbon fibre/epoxy composites containing 1, 5 and 15 mm le ngth fibres is studied. The strength of all laminates showed a sensiti vity to the radius of curvature, with the tensile strength decreasing at smaller radii of curvature. A model is developed to predict notched strength based on assumed evolution and propagation of damage from th e tip of the notch. The predictions of the model depend principally on two material properties: the unnotched tensile strength and fracture toughness. Reasonable agreement is achieved between the predicted notc hed strength and experimental data.