In-service damage

Cracks , e.g. from overload, fatigue, oxidation, chemical attack, UV degradation

Delamination, e.g. from, overload or fatigue

Fibre buckling, e.g. from overload or fatigue

Loss of fibre, e.g. from chemical attack

Pitting and etching, e.g. from chemical attack

Softening, e.g. from fluid absorption, temperature excursions

Blistering, e.g. from chemical attack, temperature excursions

Discoloration, e.g. from UV degradation, chemical attack

Charring and Fire, e.g. exposures to excessive radiant, conductive or flame heat sources.

Leaching, e.g. from chemical attack

Wear, abrasion and erosion, e.g. from parts experiencing multiple repetitive contact with another material

Impact damage needs to be treated separately as it can be a combination of matrix cracks, delamination and fibre failure, the nature of which depends on the structure and the nature of the impact. Impacts fall into different categories

• Low velocity, e.g. hail stones , tool drops, bird strikes
• High mass impacts, e.g. collisions
• High velocity, e.g. ballistic, turbine blade separation
• An alternative impact damage is the lightning strike that also incorporates thermal and electrical excursions