An Eddy-Current Model for Three-Dimensional Nondestructive Evaluation of Advanced Composites

Abstract

The research problem is to develop a model and an inversion algorithm suitable for the three-dimensional quantitative nondestructive evaluation (NDE) of advanced composite materials by using eddy currents. The technical objectives are to determine the feasibility of using multifrequencies for this job, to determine in localized regions the fiber-resin ratio in graphite epoxy, and to determine more precisely the types of anomalies, whether flaws, delaminations, broken fibers, etc., that can be reconstructed by the inversion method. These objectives are met by: (1) applying rigorous electromagnetic theory to determine a Green's function for a slab of anisotropic composite material, (2) determining the integral relations for the direct and inverse problems using the Green's function just derived, (3) determining suitable numerical algorithms for solving the inverse problem, and (4) writing a computer program to execute the model. These objectives have been met; in addition we illustrate some interesting electromagnetic phenomena in composite materials.

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Document Details

Document Type
Technical Report
Publication Date
Jul 28, 1985
Accession Number
ADA167688

Entities

People

  • Harold A. Sabbagh
  • L. David Sabbagh
  • Thomas M. Roberts

Tags

Communities of Interest

  • Advanced Electronics
  • Air Platforms
  • Biomedical
  • Sensors
  • Weapons Technologies

DTIC Thesaurus Topics

  • Aircraft Industry
  • Aircrafts
  • Algorithms
  • Artificial Intelligence
  • Carbon Fibers
  • Commercial Aircraft
  • Composite Materials
  • Computer Programs
  • Computers
  • Differential Equations
  • Electromagnetic Fields
  • Electromagnetism
  • Graphitic Materials
  • Integral Equations
  • Inverse Problems
  • Laminates
  • Magnetic Fields

Readers

  • Calculus or Mathematical Analysis
  • Computational Modeling and Simulation
  • Structural Health Monitoring of Composite Structures.