Accession Number:

ADA625732

Title:

Electromagnetic Energy Localization and Characterization of Composites

Descriptive Note:

Doctoral thesis

Corporate Author:

NORTH CAROLINA STATE UNIV AT RALEIGH DEPT OF ELECTRICAL AND COMPUTER ENGINEERING

Personal Author(s):

Report Date:

2013-01-01

Pagination or Media Count:

149.0

Abstract:

This dissertation examines the electromagnetic EM properties of two component composites. These composites exhibit varying degrees of complexity, ranging from those containing single cube inclusions to those consisting of hundreds of irregularly shaped inclusions in a disordered arrangement. Specifically, time-domain EM modeling is used as a tool to calculate effective permittivity as well as EM localization behavior for these mixtures. For single inclusion mixtures with high permittivity contrast between the inclusion and the surrounding matrix material, strong deviation from established mixing theories is found. It is also shown that the orientation of the inclusion impacts the effective electrical permittivity of the composite. Electric fields are found to localize on the edges and corners of an irregular inclusion independent of simulation boundary conditions. Increasing the complexity of the studied mixtures, the EM properties are then analyzed for mixtures containing many irregularly- and regularly-shaped inclusion crystals. A strong correlation between effective permittivity and cross-sectional area is found for these mixtures. With hundreds of inclusion crystals with either irregular or cube shapes, the change in inclusion shape causes negligible differences in effective permittivity. Electric energy density localizes on edges and corners of inclusions regardless of inclusion shape. A result not highlighted by single inclusion mixtures, for composites containing numerous inclusions significant increases in energy localization are observed as the EM signal travels through more inclusions. This increase in hotspot magnitude is observed for complex mixtures with hundreds of disordered irregularly shaped inclusion crystals. The same behavior is also observed for the much simpler scenario of a few dozen cube inclusions distributed within discrete parallel planes.

Subject Categories:

  • Electricity and Magnetism

Distribution Statement:

APPROVED FOR PUBLIC RELEASE