Preliminary Evaluation of the Potential and Limitations of Microwave NDI Methods for Inspecting Graphite Composites
The potential for using microwave nondestructive testing methods for inspecting graphite composites to detect embedded materials and impact damage are examined in this paper. Specially prepared graphite/epoxy panels are inspected with an open-ended waveguide reflectometer at various frequencies and liftoffs. The results show the possibility of manipulating signal polarization (with respect to the fiber orientation) to detect embedded materials. For cross-ply laminates, the microwave signal is almost totally reflected off of the surface and no appreciable signal penetration is possible. However, impact damage, a surface defect, is detected both in unidirectional and cross-ply laminates. These preliminary results are encouraging for the use of microwave signals when inspecting certain graphite composite structures.
R. Zoughi et al., "Preliminary Evaluation of the Potential and Limitations of Microwave NDI Methods for Inspecting Graphite Composites," Materials Science Forum, vol. 210-213, pp. 611-618, Trans Tech Publications, May 1996.
The definitive version is available at http://dx.doi.org/10.4028/www.scientific.net/MSF.210-213.611
Electrical and Computer Engineering
Keywords and Phrases
Crystal Defects; Crystal Structure; Graphite; Laminated Composites; Microwaves; Nondestructive Examination; Polarization; Reflectometers; Surfaces; Cross Ply Laminates; Embedded Materials; Impact Damage; Microwave Signals; Open Ended Waveguide Reflectometer; Signal Polarization; Composite Materials; Embedded Defects; Graphite Composites; Microwave Nondestructive Inspection
International Standard Serial Number (ISSN)
Article - Journal
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