TRANSVERSE CONDUCTIVITY IN NONIDEAL FIBER-COMPOSITE GEOMETRIES

An ideal fiber composite is defined as one with parallel circular fibe rs forming a regular array. We consider how the thermal conductivity t ransverse to the overall fiber direction is affected by departures fro m the ideal geometry, such as irregular stacking pattern, misalignment of fibers and unequal or non-circular cross sections. Illuminating ex amples are discussed, quantitatively and qualitatively. In particular, we derive an effective-medium result for slightly misaligned fibers. It is found that for fiber concentrations not close to a percolation t hreshold, the effect of non-ideal geometry is normally too small (< 1 % in many realistic examples) to be of any practical importance.