  Explicit expressions for the behavior of statistically isotropic composites
with viscoelastic matrices and linear elastic inclusions are determined by
application of the correspondence principle. The behavior of the matrix is
linear in dilatation and governed by the standard linear model in shear. We
demonstrate that in some cases explicit expressions for the behavior of
composites with more general behaviors of the matrix can be derived. We also
show that under certain loading conditions the response of the composite may be
non-monotonous. This is the result of the interaction between two phases with
different viscoelastic behaviors and may appear for more general materials.
