The thermal conductivity and the coefficient of thermal expansion of spatially reinforced composites(SRC) were predicted by applying the volume averaging method which employs existing micromechanical theories and conventional transformation rules to constitute relations for the unit cells of the composites. The thermal conductivity of the composites was also calculated by the application of the thermal resistance method which defines resistance as the ratio of a driving potential to the corresponding transfer rate and which uses an analogy between the diffusion of heat and electrical charge. There is a little difference between the results of two prediction schemes for thermal conductivity.
To verify the theoretical predictions, the thermal conductivity of 4-D composites was examined experimentally. The comparison of the numerical results with those measured by the experiment showed good agreement.
As an application of the developed program, the thermal properties of the throat part of a kick motor nozzle made of the carbon/carbon SRC were predicted and the finite element method was used to analyze the thermal behavior of the nozzle. This analysis showed that the transverse thermal conductivity of SRC has more effects on the temperature distribution of the throat than the axial thermal conductivity of SRC has and that the thermal deformation of 4-D SRC is smaller than that of 3-D SRC.
