Surface and bulk stress/strain measurements in composite laminates with a fibre-optic Raman probe

Arjyal, BP; Tarantili, PA; Andreopoulos, AG; Galiotis, C

dc.contributor.author	Arjyal, BP	en
dc.contributor.author	Tarantili, PA	en
dc.contributor.author	Andreopoulos, AG	en
dc.contributor.author	Galiotis, C	en
dc.date.accessioned	2014-03-01T01:15:16Z
dc.date.available	2014-03-01T01:15:16Z
dc.date.issued	1999	en
dc.identifier.issn	1359-835X	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/13399
dc.subject	stress	en
dc.subject	laminates	en
dc.subject.classification	Engineering, Manufacturing	en
dc.subject.classification	Materials Science, Composites	en
dc.subject.other	Elastic moduli	en
dc.subject.other	Epoxy resins	en
dc.subject.other	Fiber reinforced plastics	en
dc.subject.other	Fracture mechanics	en
dc.subject.other	Mechanical variables measurement	en
dc.subject.other	Poisson ratio	en
dc.subject.other	Probes	en
dc.subject.other	Raman spectroscopy	en
dc.subject.other	Strain gages	en
dc.subject.other	Tensile strength	en
dc.subject.other	Tensile stress	en
dc.subject.other	Fiber optic Raman probe	en
dc.subject.other	Fiber stress measurements	en
dc.subject.other	Polydiacetylene	en
dc.subject.other	Strain measurements	en
dc.subject.other	Tensile load	en
dc.subject.other	Laminated composites	en
dc.title	Surface and bulk stress/strain measurements in composite laminates with a fibre-optic Raman probe	en
heal.type	journalArticle	en
heal.identifier.primary	10.1016/S1359-835X(99)00025-1	en
heal.identifier.secondary	http://dx.doi.org/10.1016/S1359-835X(99)00025-1	en
heal.language	English	en
heal.publicationDate	1999	en
heal.abstract	Fibre stress/strain measurements in unidirectional, as well as, multidirectional aramid/epoxy composites have been conducted with the use of a laser Raman microprobe. The composite was incrementally loaded in tension while Raman measurements were taken. Fibre-optic probes sandwiched between adjacent laminae were employed for channelling the laser excitation light to a specified location within the bulk of the composite. The direction of the fibre-optic was either perpendicular or parallel to the reinforcing fibres. For comparison purposes, the same fibre-optic probe was used to scan the surface of the laminates. The perpendicular configuration was found to reduce the tensile strength of the as-received composite coupon by 10% whereas the parallel second configuration had no effect. In the unidirectional coupons the stress or strain in the principal fibre direction could be measured prior to loading and at every increment of applied tensile load up to fracture. The take-up of fibre strain for both bulk and surface set of measurements was identical with that obtained from the attached electrical resistance strain gauges. In the case of multidirectional coupons the stress or strain in the principal direction could be measured within successive plies situated at angles theta to the loading direction. The results for the 0 degrees plies were in good agreement with those obtained by conventional laminate analysis whereas small deviations from linearity were observed in the angle plies. The proposed methodology paves the way for simultaneous in-service stress/strain measurements on the reinforcing fibres situated on the surface or within the bulk of a composite laminate. (C) 1999 Elsevier Science Ltd. All rights reserved.	en
heal.publisher	Elsevier Science Ltd, Exeter, United Kingdom	en
heal.journalName	Composites Part A: Applied Science and Manufacturing	en
dc.identifier.doi	10.1016/S1359-835X(99)00025-1	en
dc.identifier.isi	ISI:000082132600005	en
dc.identifier.volume	30	en
dc.identifier.issue	10	en
dc.identifier.spage	1187	en
dc.identifier.epage	1195	en