ROLE OF INTERPHASE ON THE ELASTIC BEHAVIOR OF COMPOSITE-MATERIALS - THEORETICAL AND EXPERIMENTAL-ANALYSIS

The study and design of composite structures raises numerous difficult ies due to the high level of heterogeneity and to the small size of th e fillers. One of the most usual solutions consists in replacing the c omposite material by a homogeneous medium which is considered as ''mac roscopically'' equivalent. This kind of approach, named homogeneizatio n, aims to provide every mechanical characteristic of the composite ac cording to the mechanical and geometrical features of its constituents . The aim of the present paper is twofold: (1) to review the most usua l homogeneization approaches for linear elastic behavior in order to o btain their own range of validity in comparison with experimental data , and (2) to determine experimentally and numerically the effect of a third phase, named interphase, on the linear elastic behavior of fiber composites.