LIMITS OF CONVENTIONAL MICROMECHANICAL ANALYSIS OF INTERFACE PROPERTIES IN GLASS EPOXY MODEL COMPOSITES

Pull-out and fragmentation tests have been used to evaluate the influe nce of silane sizing on the interfacial load transfer in glass-epoxy m odel composites. It appears that the amount of silane dissolved in the matrix modifies substantially the mechanical properties of the matrix near the interface and hence the damage modes of the model composite. Thus the standard analysis of these micromechanical tests turns out t o be insufficient and unsuitable. The authors attempt to analyse exper imental fragmentation curves with an analytical computation based on a two-dimensional load-transfer model. In spite of an excellent agreeme nt between experiments and simulation, insufficiencies in the model ha ve been identified. Accordingly, care is required in using data drawn from pull-out and fragmentation tests and an effort must be made to im prove their mechanical analysis.