6533b834fe1ef96bd129e129
RESEARCH PRODUCT
Simultaneous measurement of temperature and strain in glass fiber/epoxy composites by embedded fiber optic sensors: I. Cure monitoring
Roberto MontaniniLeonardo D'acquistosubject
Materials scienceFiber Bragg grating (FBG) sensorsComposite numberGlass fiberFiber Bragg gratingComposite cure monitoringSettore ING-IND/12 - Misure Meccaniche E TermicheSITUTemperature mesurementGeneral Materials ScienceCure monitoringElectrical and Electronic EngineeringComposite materialBRAGG GRATING SENSORSCivil and Structural EngineeringOptical fiber sensorEpoxyFibre-reinforced plasticCondensed Matter PhysicsTHERMOSETFiber Bragg grating (FBG) sensors; Optical fiber sensor; Composite cure monitoring; Strain measurement; Temperature mesurementAtomic and Molecular Physics and OpticsMechanics of MaterialsFiber optic sensorvisual_artSignal Processingvisual_art.visual_art_mediumEPOXY-RESINStrain measurementStructural health monitoringFIBRE/EPOXY COMPOSITESSYSTEMdescription
In this paper (Part I) the use of fiber optic sensors for real-time monitoring of the cure kinetics of GFRP composites is explored. The proposed sensing system allows the simultaneous measurement of both temperature and strain by monitoring the change in reflected wavelength from two coupled fiber Bragg grating (FBG) sensors that have been embedded into the composite laminate. Instrumented GFRP laminates with 12, 18 and 24 reinforcing plies, respectively, were prepared by means of the vacuum bagging technique. Samples were cured in a thermally controlled oven at 80 degrees C and 30 kPa for 240 min (isothermal stage) and then cooled down to ambient temperature by turning off the heating source (cooling stage). The obtained results, combined with proper data post-processing, have proven the effectiveness and potentiality of the proposed sensing system to measure the progression of the composite cure kinetics. It was shown that temperature within the specimen can differ significantly from the set-point temperature inside the oven because of the heat released during the exothermal reticulation of the epoxy resin. The combined sensing system also allowed the residual strain accumulated within the composite during the cooling stage to be accurately measured. Once the laminate had been cured, the embedded optical sensing system reveals itself purposeful for real-time structural health monitoring and damage assessment of the finished component. This aspect is discussed with more detail in the accompanying paper (Part II).
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2007-08-13 |