This work concerns heterogeneous multiphase materials which may exhibit
omnidirectional full or partial cocontinuity of several or all phases. The estimate of
their effective (mechanical or physical) properties is not yet well handled as compared
to those for well-defined aggregate or reinforced-matrix structures, especially in the
context of homogenization methods. We propose in this framework a modeling
scheme which aims at accounting for such phase cocontinuity features. In the
mechanical application field, the modeling validity restricts to elastic properties of
unloaded materials or in load situations as far as bending and torsion effects of
possibly strut-like phase parts are not essential. For other physical properties
(dielectric, magnetic, etc.), the modeling applications concern those for which
homogenization approaches are relevant. The modeling is based on a material’s
morphology description in terms of a generalization of so-called “fiber systems” that
were introduced in early literature reports. Using parameters that describe the
clustering characteristics of the individual phases and of their assemblage, we have
considered these fiber systems both within a layer-based approach of the
material structure and within an aggregate-like one. By these two routes, we
have obtained two estimate forms that differ only slightly in definition. The
presentation uses the elasticity formalism, in simple cases of isotropic mixtures of
two-phase materials with isotropic phase behavior but the modeling extends to
-phase
anisotropic materials as established separately. Our estimates are compared
with basic variational bounds and homogenization estimates, with some
literature data and with homogenization results obtained with the fast Fourier
transform approach on numerical structures. All data are matched with different
parameter sets corresponding to different types of phase organization. The two
estimates remain nearly equal for all of the examined structures regardless of
phase contrast and with only slight differences consistent with their definition
difference.