Then we would seek to understand how the
material is to be used and analyze that configuration
based on the principles of heat transfer or
structural analysis. If the materials were complex in
form, we would expect the property data to be "effective"
since the engineering analysis we would
use would most likely be based on a model for simple
homogeneous materials. For example, a measured
thermal conductivity of a foam material
would represent all the underlying heat transfer
processes in the foam. Its measured thermal conductivity
would not be that of the pure material or
the entrapped air in the foamed material, but it
would be an "effective" value based on Fourier's
law of heat conduction applied to the foam. Obviously,
the effects on a material in a fire are more
complex than this. But by using simple theories
based on scientific analysis, we should be able to
derive and utilize "effective" property data in an
analogous fashion.