3. Fiber/matrix interface analysis

While it is common practice to analyze the behavior of composites as a function of their two basic components, matrix and reinforcement, the scientific and technical literature is much more discreet about the influence of the interface (sometimes referred to as the interphase). The difficulty lies in the fact that the notion of interface remains relatively vague, that the interfacial zone does not exist per se, that it is only created during composite processing and that it is difficult to attribute a set of mechanical properties to it.

However, since the interface ensures continuity between two different materials - fibers and resin - a lack of adhesion leads to mechanical behavior problems, since the interface fulfills a dual function of protecting the fibers from external aggression, particularly hydrothermal, on the one hand, and transmitting inter-fiber forces...