Published In

Journal of Nondestructive Evaluation

Document Type

Pre-Print

Publication Date

3-28-2016

Subjects

Tomography, Nanostructured materials, Nanotechnology

Abstract

This paper describes a novel non-destructive evaluation methodology for imaging of damage in composite materials using the electrical impedance tomography (EIT) technique applied to a distributed carbon nanotube-based sensor. The sensor consists of a nonwoven aramid fabric, which was first coated with nanotubes using a solution casting approach and then infused with epoxy resin through the vacuum assisted resin transfer molding technique. Finally, this composite sensor is cured to become a mechanically-robust, electromechanically-sensitive, and highly customizable distributed two-dimensional sensor which can be adhered to virtually any substrate. By assuming that damage on the sensor directly affects its conductivity, a difference imaging-based EIT algorithm was implemented and tailored to offer two-dimensional maps of conductivity changes, from which damage location and size can be estimated. The reconstruction is based on a newly defined adjacent current–voltage measurement scheme associated with 32 electrodes located along the boundary of the sensor. In this paper, we evaluate our methodology first by introducing well-defined damage where sections are either removed or narrow cuts are made on a series of sensor specimens. Finally, a more realistic damage scenario was investigated to show the capability of our methodology to detect impact damage on a composite laminate. The resulting EIT maps are compared to visual inspection and thermograms taken with an infrared camera.

Description

This is the author’s version of a work. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document.

DOI

10.1007/s10921-016-0341-0

Persistent Identifier

http://archives.pdx.edu/ds/psu/18881

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