Abstract
With an effective-medium approach, the conductivity of two-phase random composites is investigated with particular reference to structures in these materials. A model is given of such structures in terms of four types of cells: two of them are complex cells, each consisting of a core and a shell, and the other two are simple cells, each consisting of a single phase. The effective conductivity is derived by applying an effective-medium method self-consistently to an assembly of such cells. The calculated result is in good agreement with experimental data for various materials. Structural information of actual composites is elicited, though crudely, by applying the present model.