A Quasidependent Scattering Radiative Properties Model for High Density Fiber Composites

Abstract

This paper presents a theoretical model for the radiative properties of fiber composites fabricated of spatially oriented fiber strands that contain closely spaced fibers in the Mie scattering regime. Dependent scattering within the dense fiber strands is accounted for by utilizing the solution of Maxwell’s equations that included the near field interaction of cylindrical waves. Scattering between strands is shown to be uncorrelated due to their macroscopic dimensions compared with the wavelength of the incident radiation. The model is called quasidependent scattering approximation (QDA), as the radiative properties are formulated as the uncorrelated sum of the dependent scattering properties of the constituent fiber strands. The extinction coefficient, scattering coefficient, and scattering phase function are derived for fiber composites of arbitrary internal architecture. The application of the QDA model is demonstrated by means of numerical analyses on two types of fiber composites.