Condition Monitoring of Textiles Using Optical Techniques

In the paper it is proposed to use fibre Bragg grating (FBG) sensors to monitor the deformation and strain in a woven textile. Non-contact digital image correlation (DIC) is used to validate the results. The principal objective of the work in this paper is to identify a suitable adhesive for attaching the FBG sensors to tapestries and textiles. To do this, the interfacial interactions of the optical fibre, the textile material and the necessary adhesive must be considered. The performance of two types of adhesive are studied: a PVA conservation adhesive and a two-part epoxy adhesive Araldite 2015. The effect of the application of the adhesives on the mechanical response of the textile is investigated. Full-field stain maps are obtained from the DIC and are used as the basis to characterise the behaviour of the FBG sensors/adhesive system. The strain transfer coefficients and a reinforcement factor are determined under quasi-static conditions. It is shown that the local reinforcement introduced is more significant in the specimen with the FBG bonded using the Araldite adhesive than those with conservation adhesives. Nevertheless, the Araldite adhesive has a better strain transfer coefficient than the conservation adhesive, although not as high as that expect with conventional engineering materials.