Created by the need to ensure the basic structural repair and maintenance of structural parts of a military aircraft, and to improve structural maintenance during their operational life, this research set itself the objective of experimental activities to realize new "nanostructured repair" materials able to integrate with the conventional materials used on aircraft.
These new material demonstrators were made by blending CNTs (Carbon Nano Tubes) with known polymers already in use in industry. The results of the experimental campaign were encouraging: it was possible to verify their effectiveness in the laboratory, with the recovery of about 98% of the initial structural behaviour of the undamaged aluminium sample.
To achieve this goal, the research programme experimentally reproduced the method applied to the repair of cracks in aluminium materials, simulating in the laboratory the damage of a specimen (crack) with the subsequent application of a patch repair, using a binder based on the new composite made of an industrial polymer and CNT.
Context and outlook
Maintaining or restoring the operational efficiency of military aircraft requires advanced technologies for both structural integrity and its maintenance. This is even more true when restoring structural damage occurred during service, or as a suitable ABDR repair method in operating environments defined as "out of area". Among the innovative materials most frequently used in aviation, carbon fibres occupy a leading position.
These materials, however, are particularly sensitive to concentrated and/or impulsive loads that stress the material locally, with the risk of serious structural damage. Currently available repairs are invasive and time-consuming, and require specific tools and an equipped environment to ensure the acceptability of the repaired component.
A research programme is therefore envisaged to define a non-invasive maintenance and repair method, able to restore structural continuity to the original static value and to provide elements for verifying the recovery of the repaired part's characteristics. The programme also aims to identify and provide portable prototypes of diagnostic tools for extraordinary maintenance and repair in "out of area" operating environments, with simplified interventions and a consequent reduction in aircraft management costs.