  An effective model of single and multilayered thin panels, including those
formed using carbon fiber composite (CFC) materials, is incorporated into the
Transmission Line Modeling (TLM) method. The thin panel model is a
one-dimensional (1D) one based on analytical expansions of cotangent and
cosecant functions that are used to describe the admittance matrix in the
frequency domain; these are then converted into the time domain by using
digital filter theory and an inverse Z transform. The model, which is extended
to allow for material anisotropy, is executed within 1D TLM codes. And, for the
first time, the two-dimensional (2D) thin surface model is embedded in
unstructured three-dimensional (3D) TLM codes. The approach is validated by
using it to study some canonical structures with analytic solutions, and
against results taken from the literature. It is then used to investigate
shielding effectiveness of carbon fiber composite materials in a practical
curved aerospace-related structure.
