ABSTRACT
The notched strength of thermoplastic composites is studied experimentally and theoretically. Two graphite/polyethereketone material systems (XAS/APC-1 and AS4/APC-2) were chosen to fabricate quasi-isotropic and orthotropic laminates with either a circular hole or a slanted crack. Thermoplastic composites have lower compressive strength compared to graphite/epoxy laminates. The experimental program was designed to show the hole size effects on the notched strength of these laminates containing either a circular hole or a slanted crack. The point strength model and the minimum strength model in conjunction with a first-ply failure criterion or a lamina-based fiber failure criterion are applied to predict the notched strength of the laminates. All the specimens tested were finite width. Therefore, the ultimate strengths were corrected using finite-width correction (FWC) factors to obtain the notched strengths of the infinite-width plates. The opening to width ratios of the specimens are less than 1/3, therefore the isotropic FWC factors can be used for crossply laminates with no significant errors.
