Estimation of Electrical Conductivity and Electromagnetic Shielding Characteristics of Graphite/Epoxy Laminates

Abstract

The low electrical conductivity of advanced composites relative to metals presents the design engineer with potential problems when utilizing composites in the construction of primary aircraft components. This con ductivity is the key material property that governs the vulnerability of sensitive circuitry inside an aircraft when exposed to electromagnetic inter ference due to lightning, nuclear detonations or powerful transmitters. This paper presents experimentally verified analytical expression to esti mate the basic electrical conductivity and electromagnetic shielding charac teristics of bare and protected graphite/epoxy laminates. These expressions can be used to compare the electrical performance of various configura tions of graphite/epoxy laminates and candidate protective coatings that will improve the shielding characteristics.