Measurement of the thermal diffusivity of a silica fiber bundle using a laser and an IR camera

Abstract

(A3600GV) We propose a lightweight method for the determination of heat difusivity of silica fiber bundles based on the use of a laser and an IR camera. The fiber bundle is maintained in traction in a holder ; exposition is made as a step function, followed by a laser shutdown. The movie obtained by the IR camera is then processed : frame averaging, background computation and subtraction, image smoothing, extraction of the IR signal along the fiber bundle. A 1D model has been developed. This problem admits an analytic solution that we have obtained through the use of Laplace transforms. Several identification methods are proposed and tested, and have been compared favorably with an existing method based on periodic heating. Results are in agreement with literature values.

Characterizing the Thermal Diffusivity of Single, Micrometer-Sized Fibers via High-Resolution Lock-In Thermography

“…Vignoles et al presented a transient method to characterize fibers. 16 They compared different evaluation models and showed a good agreement between all models. However, they exclusively measured a 450 μm thick silica fiber bundle with a low diffusivity (≈0.2 mm 2 s −1 ).…”

“…Afterward, an appropriate model analyzes the resulting data. Vignoles et al presented a transient method to characterize fibers . They compared different evaluation models and showed a good agreement between all models.…”

Thermographic and tomographic methods for tridimensional characterization of thermal transfer in silica/phenolic composites

“…The matrix thermal properties were obtained using flash thermography (diffusivity) and DSC (heat capacity). The fiber heat capacity was obtained by subtraction between the composite and the matrix values, and its diffusivity by a specific laser excitation method [10]. The reported values will be used in the numerical computations based on tomographic images.…”