Optical coherence tomography (OCT) is a non-destructive and non-contact technique to image microstructure within scattering media. The application of OCT to highly scattering materials such as polymer composites is especially challenging. In this work, OCT is evaluated as a technique to image fiber tows and voids in an epoxy and in a vinyl ester E-glass reinforced composite. Features detected using OCT are compared with optical microscopy. The quality of the OCT image is strongly affected by the refractive index mismatch between the fibers and reinforcement. The largest sources of noise in the images arises from fiber lens effects and interference from within the sample and a very large reflection at the surface.
Citation: Composites Engineering
Pub Type: Journals
composites, imaging, microstructure, non-destructive evaluation, optical coherence tomography