Response of fiber Bragg gratings bonded on a glass/epoxy laminate subjected to static loadings

Matthieu Mulle, Ali Moussawi, Gilles Lubineau, Samuel Durand, Didier Falandry, Philippe Olivier

Research output: Contribution to journalArticlepeer-review

22 Scopus citations

Abstract

Fiber Bragg gratings (FBG) may be used to monitor strain over the surface of a structure as an alternative technology to conventional strain gauges. However, FBG bonding techniques have still not been established to yield satisfactory surface measurements. Here, two adhesives were investigated, one with low viscosity and the other with high viscosity for bonding FBGs on glass/epoxy sandwich skins. First, instrumented elementary specimens were tested under tension. FBG strain results were analyzed together with digital image correlation (DIC) measurements. The influence of the bonding layer on the measured strain and on the integrity of the sensor was investigated by considering different regions of interest. Next, an instrumented structural sandwich beam was tested under four-point bending. FBG rosettes were compared to conventional strain gauge rosettes. The high viscosity adhesive demonstrated behaviors that affected FBG accuracy. Brittleness of the bonding layer and poor interface adhesion were observed using DIC and X-ray tomography. By contrast, the low viscosity adhesive demonstrated satisfactory results. The FBG strain measurements appeared to be consistent with those of DIC. The accuracy is also adequate as the FBGs and the conventional strain gauges had similar results in three directions, under tension and under compression.
Original languageEnglish (US)
Pages (from-to)75-84
Number of pages10
JournalComposite Structures
Volume130
DOIs
StatePublished - Apr 25 2015

ASJC Scopus subject areas

  • Civil and Structural Engineering
  • Ceramics and Composites

Fingerprint Dive into the research topics of 'Response of fiber Bragg gratings bonded on a glass/epoxy laminate subjected to static loadings'. Together they form a unique fingerprint.

Cite this