Title

Preliminary Evaluation of the Potential and Limitations of Microwave NDI Methods for Inspecting Graphite Composites

Abstract

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.

Department(s)

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)

0255-5476

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 1996 Trans Tech Publications, All rights reserved.

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