ABSTRACT
The ultimate strength of composite laminates containing elliptical openings can be predicted reasonably well using two failure models which utilize the first-ply failure (FPF) strength of the notched and corresponding unnotched laminates. Two strength models using the exact two-dimensional stress distribution and FPF criterion are Point Strength Model and Minimum Strength Model. In modeling the notched strength of laminated composites the following facts must be considered: the stress concentration at the opening edge cannot explain the hole size effect, and the stress profiles for different hole sizes are different. The predictions of the point strength model and the minimum strength model are compared to experimental results. In general, the prediction using the minimum strength model is more accurate than that of the point strength model. The most common implanted crack used in the experimental work is produced by using a 0.005 in. diameter diamond-impregnated wire.
