The notched strength of angle-ply laminates

grantor: University of TorontoThe notched tensile strength of carbon-epoxy and glass-epoxy laminates with 43mm width and 20mm gauge length were studied at different fiber lay-up angles and quasi-isotropic laminates. Mostly fiber failure was observed for 15° and 30° laminates. With angles greater than 45°, fiber failure hardly occurred at all. The photoelastic method was used in the study. The fringe patterns showed that the stress distributions in angle-ply laminates were different from those for isotropic materials. The quasi-isotropic laminates were very similar to isotropic materials. The results showed that KIc can be measured for both carbon-epoxy and glass-epoxy angle-ply laminates for fiber angles at 30° or less; and for quasi-isotropic carbon-epoxy. It still had some validity at 45° or higher. KIc's of up to 86MPam1/2 were observed. Work of fracture estimated therefore would be as high as 740 kJm-2 .M.A.Sc