  In our previous papers we have described efficient and reliable methods of
generation of representative volume elements (RVE) perfectly suitable for
analysis of composite materials via stochastic homogenization.
  In this paper we profit from these methods to analyze the influence of the
morphology on the effective mechanical properties of the samples. More
precisely, we study the dependence of main mechanical characteristics of a
composite medium on various parameters of the mixture of inclusions composed of
spheres and cylinders. On top of that we introduce various imperfections to
inclusions and observe the evolution of effective properties related to that.
  The main computational approach used throughout the work is the FFT-based
homogenization technique, validated however by comparison with the direct
finite elements method. We give details on the features of the method and the
validation campaign as well.
  Keywords: Composite materials, Cylindrical and spherical reinforcements,
Mechanical properties, Stochastic homogenization.
