Measurement of the electromagnetic shielding properties of mechanically loaded composites

The use of fiber reinforced plastic (FRP) composites for large structures is becoming more widespread. With composites increasingly called upon to replace structures traditionally Fabricated from metals the requirement to find suitable methods of providing adequate electromagnetic shielding (EMS) is often of prime importance. This paper describes a measurement technique employing induced magnetic eddy currents for assessing electromagnetic shielding. The technique does not require costly screened rooms or large test panels and is portable and easy to use. The effectiveness of the technique for comparing the electromagnetic shielding of material samples after mechanical loading is demonstrated, and it is concluded that the method offers a cheap and reliable means of comparing screening solutions for composite materials in high loading or fatigue applications. The potential for development of the method into a through-life shielding monitoring tool is also highlighted.