title: Self-Sensing Composites: In-Situ Detection of Fibre Fracture.
abstract: The primary load-bearing component in a composite material is the reinforcing fibres. This paper reports on a technique to study the fracture of individual reinforcing fibres or filaments in real-time. Custom-made small-diameter optical fibres with a diameter of 12 (±2) micrometres were used to detect the fracture of individual filaments during tensile loading of unreinforced bundles and composites. The unimpregnated bundles were end-tabbed and tensile tested to failure. A simple technique based on resin-infusion was developed to manufacture composites with a negligible void content. In both cases, optical fibre connectors were attached to the ends of the small-diameter optical fibre bundles to enable light to be coupled into the bundle via one end whilst the opposite end was photographed using a high-speed camera. The feasibility of detecting the fracture of each of the filaments in the bundle and composite was demonstrated. The in-situ damage detection technique was also applied to E-glass bundles and composites; this will be reported in a subsequent publication.
authors.affiliation: School of Metallurgy and Materials, University of Birmingham, Birmingham B15 2TT, UK. shoaibamalik@yahoo.com.
authors.forename: Shoaib A
authors.initials: SA
authors.lastname: Malik
authors.affiliation: School of Metallurgy and Materials, University of Birmingham, Birmingham B15 2TT, UK. wlw@mju.edu.cn.
authors.forename: Liwei
authors.initials: L
authors.lastname: Wang
authors.affiliation: Physical Sciences Department, Dstl Porton Down, Salisbury, Wilts SP4 0JQ, UK. ptcurtis@taz.dstl.gov.uk.
authors.forename: Paul T
authors.initials: PT
authors.lastname: Curtis
authors.affiliation: School of Metallurgy and Materials, University of Birmingham, Birmingham B15 2TT, UK. g.fernando@bham.ac.uk.
authors.forename: Gerard F
authors.initials: GF
authors.lastname: Fernando
keywords: damage detection; fibre fracture; optical fibre sensors; self-sensing; structural health monitoring