Edge effects connected with thin interphases in composite materials

Different imperfect transmission conditions modelling a thin intermediate layer between two bonded materials in a dissimilar elastic strip are analysed from the point of view of possible free-edge effects. The type of imperfect model depends essentially on the mechanical properties of the interphase and can be classified as soft, comparable and stiff interfaces. Corresponding transmission conditions have been derived by asymptotic analysis. However, they are not valid, generally speaking, at a region near the free edge, where an additional boundary layer should be constructed. By using FEM the size of this region is estimated and all possible edge-effects phenomena are classified.