Development of a stochastic free edge delamination model for laminated composite materials subjected to constant amplitude fatigue loading

A stochastic delamination growth model with parameters written in terms of fracture mechanics, material, and laminate structural parameters is developed for composite laminates subjected to constant amplitude cyclic loading. The model captures the discrete stochastic nature of the delamination growth process in laminated composite materials. Experimental data obtained using AS4/3501-6 coupons with a laminate stacking sequence of [+/-45/90/0](s) verifies that the model predicts the mean and variance associated with the delamination growth. Changing only one parameter in the model enables the model to predict delamination growth behavior at several load levels. Two parameters are identified that could possibly expand the model's predictive capability to include laminate geometries other than those used to correlate the model.