Highly Effective EM Shielding Technique for Ship Composite Structures

"METSS proposes to develop low radar cross section structural composites that reliably produce a minimum of 60 dB of attenuation in the 100 kHz to 1 GHz range, when used as standalone structures or joined to metals in complex structures. The key toaccomplishing this goal is to ensure electrical connectivity across the composite-metal boundary regardless of the joining technique used. METSS will address this service requirement by rendering the matrix resin electrically conductive to such a degreethat inter-material resistivity is dramatically reduced. METSS also intends to do this without significantly altering the basic mechanical properties of the composite. Rendering the matrix resin conductive will also reduce the internal electricalresistance between adjacent conductive carbon fibers. Carbon fibers are highly conductive along the fiber direction, but less so in the cross-fiber direction. Consequently, reducing fiber to fiber resistance is important in increasing the overall levelof uniformity of conductivity throughout the composite. METSS intends to render the matrix resins electrically conductive by the incorporation of either inherently conductive polymers, conductive nano-materials, or a combination of both technologies.Because of the nature of the electrical conductivity of these two materials, corrosion at joints should be minimized. The benefits of this program are extensive. EMI shielding has been a very active f