Damage detection and conductivity evolution in carbon nanofiber epoxy via electrical impedance tomography

• Published in: Smart materials and structures Vol. 23; no. 4; pp. 45034 - 45042
• Main Authors: Tallman, T N, Gungor, S, Wang, K W, Bakis, C E
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 01.04.2014; Institute of Physics
• Subjects: carbon nonofiber; damage detection; electrical impedance tomography; Exact sciences and technology; Fundamental areas of phenomenology (including applications); Measurement and testing methods; nondestructive evaluation; Physics; self-sensing; smart materials; Solid mechanics; Structural and continuum mechanics; structural health monitoring; Temperature effect; Epoxy resin; Nanofiber; Composite material; Thermal expansion; Electrical conductivity measurement; Tomography; Nanocomposite; Carbon fiber reinforced plastics; Embedded transducer; Non destructive test; Monitoring; Damaging; Electrical impedance
• ISSN: 0964-1726; 1361-665X
• DOI: 10.1088/0964-1726/23/4/045034

Utilizing electrically conductive nanocomposites for integrated self-sensing and health monitoring is a promising area of structural health monitoring (SHM) research wherein local changes in conductivity coincide with damage. In this research we conduct proof of concept investigations using electrical impedance tomography (EIT) for damage detection by identifying conductivity changes and by imaging conductivity evolution in a carbon nanofiber (CNF) filled epoxy composite. CNF/epoxy is examined because fibrous composites can be manufactured with a CNF/epoxy matrix thereby enabling the entire matrix to become self-sensing. We also study the mechanisms of conductivity evolution in CNF/epoxy through electrical impedance spectroscopy (EIS) testing. The results of these tests indicate that thermal expansion is responsible for conductivity evolution in a CNF/epoxy composite.