Self-repairing CFRPs targeted towards structural aerospace applications

Abstract

Purpose The purpose of this paper is to describe the first experiments to manufacture self-healing carbon fiber reinforced panels (CFRPs) for the realization of structural aeronautic components in order to address their vulnerability to impact damage in the real service conditions. Design/methodology/approach The developed self-healing system is based on ring-opening metathesis polymerizations reaction of microencapsulated 5-ethylidene-2-norbornene/dicyclopentadiene cyclic olefins using Hoveyda-Grubbs’ first generation catalyst as initiator. In this work, the self-healing resin is infused into a carbon fiber dry preform using an unconventional bulk film infusion technique that has allowed to minimize the filtration effects via a better compaction and reduced resin flow paths. Infrared spectroscopy provides a useful way to identify metathesis products and therefore catalyst activity in the self-healing panel after damage. The damage resistance of the manufactured CFRPs is evaluated through hail and drop tests. Findings The self-healing manufactured panels show, after damage, catalyst activity with metathesis product formation, as evidenced by an infrared peak at 966 cm−1. The damage response of CFRPs, detected in accord to the requirements of hail impact for the design of a fuselage in composite material, is very good. The results are very encouraging and can constitute a solid basis for bringing this new technology to the self-healable fiber reinforced resins for aerospace applications. Originality/value In this paper, autonomically healing CFRPs with damage resistance and self-healing function are proposed. In the development of self-healing aeronautic materials it is critical that self-healing activity functions in adverse weather conditions and at low working temperatures which can reach values as low as −50°C.