The heterogeneous mixture properties depend on its constituents' characteristics. We examine the effective permittivity of a two-phase composite material made of epoxy resin host matrix and barium titanate (BaTiO3) filler for different volume fractions in the matrix. The task we undertake consists in finding a model of BaTiO3 particles through the computer simulations executed in PHI3D-electric field calculating package, based on the resolution of the Laplace equation using boundary integral equation method. With this aim in view we compare the measured results of the effective permittivity of the BaTiO3–epoxy resin composite samples with the simulation results for different BaTiO3 particle geometric models and for the same experimental conditions, with regard to the given volume fraction of the powder in the matrix. The experimental results are obtained through the measurements with an impedance meter in the range of frequencies from 50 Hz to 1 MHz.

The effective characteristics of composite materials depend on their inner structure. In this paper, we carry experimental validation of the computer simulations based on boundary integral equation method used for investigating the effective permittivity of two- and three-phase heterogeneous materials with cylindrical, spherical and hollow-spherical glass inclusions embedded in epoxy resin matrix. The results are also compared with the analytical formulae predictions.