The relation between fatigue life and damage accumulation of fiber-reinforced polymer composite (FRP) is not yet clarified.
For practical use of FRP, it is necessary to relate the fatigue life to the mechanism of damage accumulation. Damage formation is controlled by the mechanical behavior of the interface between the matrix and fiber. We used short glass fiber-reinforced polycarbonate composite in our experiments. By using an in situ (real time) observational fatigue testing machine, we investigated the relationship between fatigue life and damage accumulation.
From these results, the fatigue life of this material was found to be dominated by damage accumulation which results from microfracture at the interface between the matrix and fiber. This microfracture is controlled by a cycle-dependent mechanism.