3-DIMENSIONAL GRAINED COMPOSITES OF EXTREME THERMAL-PROPERTIES

A NEW CLASS of two-phase composites possessing optimal macroscopic ten sor of heat conductance is found, in which non-identical inclusions ar e spaced periodically in a matrix making a piecewise homogeneous mediu m with a microstructure. Geometrical forms of these inclusions minimiz ing the total thermal energy can bc determined numerically after the a nalytical investigation of a specific inverse boundary problem by the usage of the Newton volume potential. Grained materials of extreme coe fficients of heat expansion are also described in the case of cubic sy mmetry. These results are obtained by the application of the equi-stre ngth concept used before in the theory of elasticity.