Interlaminar fracture or delamination is a primary damage mode in laminated composites. It is caused by high interlaminar stresses which are produced by local stress raisers such as holes, free edges, ply drops, and other defects and discontinuities which may be manufacturing related or service induced. Delaminations alter internal load paths and usually contribute to the ultimate failure of the structure.

The present work is concerned with the development of a simple analytical model which permits the rapidly varying interlaminar stresses and energy release rate to be estimated by elementary means. Extensive numerical computations are avoided, and the results are obtained in closed form. The model is applied to the edge delamination specimen subjected to uniform bending and combined bending and extension loadings. Interlaminar stresses, total energy release rate, and energy release rate components are estimated.