Fatigue damage mechanics of composite materials part IV: prediction of post-fatigue stiffness

A model has been developed for predicting the stiffness of cross-ply carbon fibre composite laminates containing a notch from which damage, in the form of matrix cracks, splits and delaminations, has grown. A combination of experimental and theoretical results have been used to deduce appropriate degraded stiffness properties for the damaged regions of the laminate. These degraded stiffnesses have then been incorporated into a finite element representation of the notched laminate to predict the overall stiffness. Agreement with experimental data is satisfactory