Fatigue damage and degradation model for carbon fibre reinforced polymer materials

A major issue concerning Carbon Fibre Reinforced Polymer (CFRP) materials under cyclic loading is that the materials often undergo material degradation starting from the initial stage of the loading. For a laminate that consists of different fibre orientation plies, this becomes crucial as it causes redistribution of stresses and strains during the lifetime of the component. Understanding the importance of a reliable fatigue damage and degradation model in the development of reliability assessment of CFRP materials, the present studies contribute to this by considering the effect on a single-ply material level, exclusively under fatigue loading. The model is restricted to be applied to stiff and brittle materials with characteristic properties similar to those of carbon-epoxy composites.