Project Title:

In-Situ Fiber Optic Sensor for FTIR Monitoring of Composite Cure Cycles

04.02-3200
Project Title:In-Situ Fiber Optic Sensor for FTIR Monitoring of Composite Cure Cycles
Company:Foster Miller Inc.
Waltham, MA 02254
Principal Investigator:John Mccoy

Abstract:

Fourier transform infrared spectroscopy (FTIR) demonstrated in the laboratory is
a valuable technique for monitoring the cure cycle in advanced thermosetting composite
materials.  New infrared transmitting optical fibers together with recently developed
ruggedized FTIR instruments offer the promise that this laboratory technology can
be moved into a production environment to provide an in-situ, non-destructive evaluation
technique to determine the state of cure in thermoset composites in real time.  THis
program intends to demonstrate the feasibility of sensing and transmitting an IR
spectrum equivalent to those obtained by Young et al. at NASA Langley in the curing
cycle of a typical thermosetting resin using an optical fiber sensor transmitting
link and ruggedized FTIR analyzer.  The fibers used will be of a chalcogenide glass
capable of transmitting in the mid-IR wavelengths that will duplicate the spectral
bands analyzed ;by Young. Because of the relatively higher attenuation of light in
the chalcogtenide glasses, an alternative approach would be ;to use near-IR spectral
information in the 1 to 5 um region using very low attenuation heavy metal fluoride
glass fibers and FTIR-correlation techniques.  The Phase I program will conclusively
demonstrate whether IR transmitting optical fibers are technically and economically
feasible to provide in-situ measurements of state of cure in a thermoset composite
material.