Accurate quantification of damage in aircraft structures during their life cycle through an automated monitoring system could ensure airframe integrity and long term durability. Nonlinear Elastic Wave Spectroscopy is an innovative class of non-destructive techniques providing an extreme sensitivity in the diagnosis of manufacturing defects such as porosity, component assembly contact conditions, incipient damage in the form of micro cracks, delaminations, clapping areas, and adhesive bond weakening, which are superior to what can be obtained with traditional NDTs.

Following the automated monitoring, the next logical scientific step lies in the development of material with in-situ wound healing, that will move the intrinsic limiting material boundaries which are encountered by aerospace manufacturers. Classical healing and self-healing concepts are based on the embedding of hollow-fibres/microcapsules in the resin. A new potential class of self-healing materials can be introduced by adopting thermally reversible cross-linked polymers.

This new class of polymers is capable of healing internal cracks through thermo-reversible covalent bond formation. This new approach eliminates the need for additional ingredients such as catalyst or monomer. Moreover, these new healable resins have the built-in capability to restore mechanical properties several times through multiple cycles of healing. This allows multiple damages occurring, at the same location, to be repaired.