Modeling and simulation for effective permittivity of two-phase disordered composites

We present a simulation for the effective permittivity of two-phase disordered composites based on a three-dimensional disordered model. In this model, the inclusions can be arranged at random positions in a composite material that is simulated by 10x10x10 cubic cells. Under the condition of the quasistatic approximation, numerical calculations are performed using the finite element method. The dependence of the calculated effective permittivity on the orientation of the disordered model is investigated. In order to get the macroscopical dielectric properties of isotropic composites, an averaging method is adopted because each topological structure of the disordered model is anisotropic. Then, the effect of the permittivity contrast between the inclusions and the matrix phase of composites is studied. The numerical results obtained by the disordered model are also compared with those obtained by the classical mixing rules and the conventional periodic models. The advantage of this presented disordered model is that it can succeed in predicting the effective permittivity in the cases of high permittivity contrast and large volume fractions of inclusions by considering overlapping of inclusions. (c) 2008 American Institute of Physics.