Deep dielectric charging and subsequent electrostatic discharge in composit
e materials are growing concerns as these materials are used ever more exte
nsively in spacecraft. A previous study showed that electric properties are
critical to this problem. The goals of the current investigation are 1) ex
perimental measurements of the continuum electrical properties of a carbon
fiber/epoxy composite and 2) the creation of a composite with electrical pr
operties that can be tailored without affecting its mechanical properties.
The measurement of the conductivity and dielectric strength of carbon fiber
/epoxy composites showed that these properties are difficult to measure, ar
e dominated by details of the composite microstructure, and should not be t
reated as continuum properties. Conversely, a tailorable glass fiber/epoxy
system was created by adding conductive carbon black to the epoxy. This mat
erial has consistent and measurable properties. It has conductivity variabl
e over three orders of magnitude, and dielectric constant variable by a fac
tor of 16, with good dielectric strength and mechanical properties.