ABSTRACT
Composite materials are inherently anisotropic due to the nature of their non-homogeneous fiber-matrix construction. This directional dependence of the thermal properties is quite pronounced in carbon matrix carbon fiber composites. An experimental method to measure the thermal properties of a carbon-carbon material is discussed in this paper. The investigated material is characterized by an orthotropic thermal conductivity (two components) and isotropic volumetric heat capacity.
Thermal properties are estimated using parameter estimation techniques with experimentally measured surface heat flux and temperature histories for an experiment with two-dimensional heat flow. Particular attention is given in the paper to provide engineering insight into the experimental and analytical aspects of this method. The thermal conductivity measured parallel to the fibers is six times larger than the conductivity normal to the fiber. Experiments with one-dimensional heat flow show excellent agreement with the two-dimensional results.
