Characterization of Degradation Using Reflectance Spectroscopy (Postprint)
AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH STRUCTURAL MATERIALS DIV
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A semi-classical model of the reflectance of a complex material is modeled. Model selection techniques using this reflectance model are developed to detect molecular vibration modes measured using infrared spectroscopy. An inverse problem methodology is then used to ascertain the underlying vibrational modes associated with varying concentrations of different chemical species. These two techniques are developed to characterize the extent of material degradation through the detection of spectra associated with the chemical processes underlying the degradation process. These methods are validated using data from samples of ceramic matrix composites. The samples considered were exposed to varying amounts of thermal treatment to ascertain the effectiveness of these methods to detect degradation.
- Atomic and Molecular Physics and Spectroscopy