Interface toughness in fibre composites by the fragmentation test

In the present work it is suggested that the degree of fibre-matrix bonding can be quantified by means of an energy for the nucleation of an interfacial debond, rather than by using a stress-based interfacial parameter. The energy necessary to initiate/nucleate an interfacial crack from its associated transverse fibre break during a single-fibre fragmentation test is calculated. The interface energy for the initiation of debonding is shown to be a function of the fibre and matrix geometrical and material characteristics, and of the initial debonding length. The novelty of the present work lies in the in-depth examination of the relative roles of the physical parameters that appear in the proposed theoretical model.