Microwave Diagnosis of Low-Density Fiberglass Composites with Resin Binder
Dielectric properties of low-density fiberglass composites are studied at microwave frequencies and are related to the resin binder content and state of cure. A completely filled short-circuited waveguide method is used to study the dielectric properties of fresh and slightly cured resin binder (used in the production of low-density fiberglass composite materials) in the frequency range of 4-18 GHz. The preliminary results indicate that the dielectric properties of resin binder may be used to determine its state of cure. The same measurement approach is used to determine the dielectric properties of fiberglass materials containing uncured resin binder, no resin binder, and three different levels of resin binder. It is found that the dielectric properties of these low-permittivity and low-loss materials are very similar. Consequently, to distinguish among real fiberglass products with different resin binder levels, an open-ended rectangular waveguide measurement approach is used. This technique allows for noncontact and on-line inspection. The standoff distance is utilized as an optimization parameter increasing the sensitivity of detection to slight dielectric property variations. Two microwave images at 24 and 10 GHz of a panel containing five different fiberglass specimens are presented.
N. N. Qaddoumi et al., "Microwave Diagnosis of Low-Density Fiberglass Composites with Resin Binder," Research in Nondestructive Evaluation, vol. 8, no. 3, pp. 177-188, Taylor & Francis, Sep 1996.
The definitive version is available at https://doi.org/10.1080/09349849609409597
Electrical and Computer Engineering
Keywords and Phrases
Composite Materials; Dielectric Properties Of Solids; Fiber Reinforced Plastics; Microwaves; Optimization; Rectangular Waveguides; Sensitivity Analysis; Fiberglass Composite Materials; Fiberglass Specimens; Microwave Frequencies; Microwave Imaging; Resin Binders; Nondestructive Examination
International Standard Serial Number (ISSN)
Article - Journal
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