DAMAGE ANALYSIS OF INTERLAMINAR FRACTURE SPECIMENS

Interlaminar fracture specimens are widely used for studying the interlaminar toughness of composite laminates. The goal of this paper is to analyse delamination specimens within the framework of a damage meso-modelling of composite laminates. In this type of modelling a laminate is described as a stacking sequence of homogeneous layers and interlaminar interfaces. The interface is assumed to be damageable in order to model the delamination phenomena. In the case of the propagation of a pre-existing crack, the main parameters for the interface model identification are the critical energy release rates. Delamination specimens are here modelled as two beams connected by a damageable interface. By means of a Finite Element Scheme used in connection with a Riks-like algorithm; comparisons between numerical simulation and experiments have been performed for a wide class of specimens (D.C.B., E.N.F, E.L.S.). The results show the interest of the proposed modelling, which allows a complete simulation of delamination using of relatively little experimental data.