Smart patches: Self-monitoring composite patches for the repair of aircraft

Crossley, S; Marioli-Riga, Z; Tsamasphyros, G; Kanderakis, G; Furnarakis, N; Ikiades, A; Konstantaki, M

dc.contributor.author	Crossley, S	en
dc.contributor.author	Marioli-Riga, Z	en
dc.contributor.author	Tsamasphyros, G	en
dc.contributor.author	Kanderakis, G	en
dc.contributor.author	Furnarakis, N	en
dc.contributor.author	Ikiades, A	en
dc.contributor.author	Konstantaki, M	en
dc.date.accessioned	2014-03-01T02:49:55Z
dc.date.available	2014-03-01T02:49:55Z
dc.date.issued	2004	en
dc.identifier.issn	0277786X	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/34783
dc.subject	Aircraft repair	en
dc.subject	Bragg gratings	en
dc.subject	FBG interrogation	en
dc.subject	Self-sensing	en
dc.subject	Smart structures	en
dc.subject.other	Aluminum	en
dc.subject.other	Corrosion	en
dc.subject.other	Cost effectiveness	en
dc.subject.other	Crack initiation	en
dc.subject.other	Fiber Bragg gratings	en
dc.subject.other	Intelligent structures	en
dc.subject.other	Optical fibers	en
dc.subject.other	Repair	en
dc.subject.other	Sensors	en
dc.subject.other	Steel	en
dc.subject.other	Aircraft repair	en
dc.subject.other	Bragg grating	en
dc.subject.other	FBG interrogation	en
dc.subject.other	Self-sensing	en
dc.subject.other	Aircraft	en
dc.title	Smart patches: Self-monitoring composite patches for the repair of aircraft	en
heal.type	conferenceItem	en
heal.identifier.primary	10.1117/12.516911	en
heal.identifier.secondary	http://dx.doi.org/10.1117/12.516911	en
heal.publicationDate	2004	en
heal.abstract	Conventional aircraft repair techniques employ bolted or riveted metallic reinforcements, which frequently introduce additional stress concentrations leading to further cracking and creating areas difficult or impossible to inspect. Bonded composite repairs (""patches"") result in the elimination of stress concentrations caused by additional fastener holes, improved strength to weight ratio and present a sealed interface. This reduces even further the danger of corrosion and fretting under the repair, gives greater flexibility in design and lessens application time while lengthening fatigue life. Embedding optical fibres and sensors into the patch, and combining this with advanced data collection and processing systems, creating a so-called ""smart patch"", will enable the real-time assessment of aircraft structural integrity resulting in reliable prediction of maintenance requirements for repaired structures. This paper describes the current state of the art in smart patch technology, and includes a detailed description of the measurement problem and of the work being undertaken to solve it, at both the component and system level. An analysis of typical crack behaviour, based on FE modelling is presented and this demonstrates the need for optical strain sensors having a very short gauge length. The paper discusses the advantages and limitations of very short Fibre Bragg Gratings (FBGs) in this context and also provides early experimental data from 1mm and 2mm gratings which have been fabricated for this purpose. The paper also describes the impact of the measurement and environmental constraints on the design of the FBG interrogation system and presents the results of initial trials. The work is being undertaken in the framework of a collaborative project (ACIDS) which is co-funded by the European Commission.	en
heal.journalName	Proceedings of SPIE - The International Society for Optical Engineering	en
dc.identifier.doi	10.1117/12.516911	en
dc.identifier.volume	5272	en
dc.identifier.spage	304	en
dc.identifier.epage	315	en