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Title: OPTIMIZING A PORTABLE MICROWAVE INTERFERENCE SCANNING SYSTEM FOR NONDESTRUCTIVE TESTING OF MULTI-LAYERED DIELECTRIC MATERIALS

Abstract

The projected microwave energy pattern, wave guide geometry, positioning methods and process variables have been optimized for use of a portable, non-contact, lap-top computer-controlled microwave interference scanning system on multi-layered dielectric materials. The system can be used in situ with one-sided access and has demonstrated capability of damage detection on composite ceramic armor. Specimens used for validation included specially fabricated surrogates, and ballistic impact-damaged specimens. Microwave data results were corroborated with high resolution direct-digital x-ray imaging. Microwave interference scanning detects cracks, laminar features and material properties variations. This paper presents the details of the system, the optimization steps and discusses results obtained.

Authors:
;  [1];  [2];  [3]
  1. Evisive, Inc., Baton Rouge, LA USA (United States)
  2. Argonne National Laboratory, Argonne, IL USA (United States)
  3. Army Research Laboratory, Aberdeen Proving Ground, MD (United States)
Publication Date:
OSTI Identifier:
21371006
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1211; Journal Issue: 1; Conference: Review of progress in quantitative nondestructive evaluation, Kingston, RI (United States), 26-31 Jul 2009; Other Information: DOI: 10.1063/1.3362209; (c) 2010 American Institute of Physics
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; CERAMICS; COMPOSITE MATERIALS; CRACKS; DAMAGE; DETECTION; DIELECTRIC MATERIALS; GLASS; INTERFERENCE; LAYERS; MICROWAVE RADIATION; NONDESTRUCTIVE TESTING; PORTABLE EQUIPMENT; RESOLUTION; VARIATIONS; X RADIATION; ELECTROMAGNETIC RADIATION; EQUIPMENT; IONIZING RADIATIONS; MATERIALS; MATERIALS TESTING; RADIATIONS; TESTING

Citation Formats

Schmidt, K. F. Jr., Little, J. R. Jr., Ellingson, W. A., and Green, W.. OPTIMIZING A PORTABLE MICROWAVE INTERFERENCE SCANNING SYSTEM FOR NONDESTRUCTIVE TESTING OF MULTI-LAYERED DIELECTRIC MATERIALS. United States: N. p., 2010. Web. doi:10.1063/1.3362209.
Schmidt, K. F. Jr., Little, J. R. Jr., Ellingson, W. A., & Green, W.. OPTIMIZING A PORTABLE MICROWAVE INTERFERENCE SCANNING SYSTEM FOR NONDESTRUCTIVE TESTING OF MULTI-LAYERED DIELECTRIC MATERIALS. United States. doi:10.1063/1.3362209.
Schmidt, K. F. Jr., Little, J. R. Jr., Ellingson, W. A., and Green, W.. 2010. "OPTIMIZING A PORTABLE MICROWAVE INTERFERENCE SCANNING SYSTEM FOR NONDESTRUCTIVE TESTING OF MULTI-LAYERED DIELECTRIC MATERIALS". United States. doi:10.1063/1.3362209.
@article{osti_21371006,
title = {OPTIMIZING A PORTABLE MICROWAVE INTERFERENCE SCANNING SYSTEM FOR NONDESTRUCTIVE TESTING OF MULTI-LAYERED DIELECTRIC MATERIALS},
author = {Schmidt, K. F. Jr. and Little, J. R. Jr. and Ellingson, W. A. and Green, W.},
abstractNote = {The projected microwave energy pattern, wave guide geometry, positioning methods and process variables have been optimized for use of a portable, non-contact, lap-top computer-controlled microwave interference scanning system on multi-layered dielectric materials. The system can be used in situ with one-sided access and has demonstrated capability of damage detection on composite ceramic armor. Specimens used for validation included specially fabricated surrogates, and ballistic impact-damaged specimens. Microwave data results were corroborated with high resolution direct-digital x-ray imaging. Microwave interference scanning detects cracks, laminar features and material properties variations. This paper presents the details of the system, the optimization steps and discusses results obtained.},
doi = {10.1063/1.3362209},
journal = {AIP Conference Proceedings},
number = 1,
volume = 1211,
place = {United States},
year = 2010,
month = 2
}
  • A portable, microwave interference scanning system, that can be used in situ, with one-sided, non-contact access, has been developed. It has demonstrated capability of damage detection on composite ceramic armor. Specimens used for validation included specially fabricated surrogates, and non-ballistic impact-damaged specimens. Microwave data results were corroborated with high resolution direct-digital x-ray imaging. Microwave interference scanning detects cracks, laminar features and material properties variations. This paper will present details of the system and discuss results obtained.
  • Inspection of ceramic-based armor has advanced through development of a microwave-based, portable, non-contact NDE system. Recently, this system was miniaturized and made wireless for maximum utility in field applications. The electronic components and functionality of the laboratory system are retained, with alternative means of position input for creation of scan images. Validation of the detection capability was recently demonstrated using specially fabricated surrogates and ballistic impact-damaged specimens. The microwave data results have been compared to data from laboratory-based microwave interferometry systems and digital x-ray imaging. The microwave interference scanning has been shown to reliably detect cracks, laminar features and materialmore » property variations. The authors present details of the system operation, descriptions of the test samples used and recent results obtained.« less
  • A microwave nondestructive testing technique is discussed for detection and evaluation of voids in layered dielectric media backed by a conducting plate. This technique utilizes the phase properties of the effective reflection coefficient of the medium as a microwave signal penetrates inside the dielectric layers and is reflected by the conducting plate. Properties of the difference between this phase in the absence and presence of an air gap is investigated as a function of the void thickness, frequency, and dielectric properties of the layers. Utilizing a simple experimental apparatus measurements were also conducted, the results of which were compared withmore » the theoretical predictions. 11 refs.« less
  • Variations in dielectric constant and patterns of microwave loss have been imaged in a yttrium-doped LiNbO{sub 3} crystal with periodic ferroelectric domains with the use of a scanning-tip near-field microwave microscope. Periodic profiles of dielectric constant and images of ferroelectric domain boundaries were observed at submicrometer resolution. The combination of these images showed a growth-instability-induced defect of periodic domain structure. Evidence of a lattice-edge dislocation has also been observed through a stress-induced variation in dielectric constant.
  • Loss measurements have been carried out on a cylindrical pillbox cavity whose metallic flat end walls have been replaced by an ordered sequence of high purity sapphire and air dielectric layers. The loss of the TE{sub 01} mode at 18.99 GHz was substantially lowered. An improvement in cavity {ital Q} for this mode from 8.30{times}10{sup 3} to 531{times}10{sup 3} was observed. These experimental results closely reproduce two independent theoretical simulations. All measurements were taken at 30 {degree}C.