ABSTRACT
This chapter shows how a scientific understanding of the physical processes involved in the degradation of composite materials can lead to improvements in design and safety of structures. Unidirectional carbon fibre composites are the most widely used constitutive elements in industrial high-performance composite structures even if they are arranged to create stratified structures with the fibres in different plies arranged in a variety of directions. Degradations which can develop in these plies are prejudicial for the mechanical integrity of the structure. A multi-scale process is the solution to this problem as it is capable of both addressing the finest parts of the structure, together with their physical characteristics, and describing the whole structure with reasonable calculation times. The fineness of the carbon fibres means that their organisation within a composite cannot be precisely controlled and as a consequence the overall distribution of the fibres in a (0°) carbon/epoxy laminate is never regular.
