  The effect of the clusterization on the effective properties of a composite
material reinforced by MXene or graphene platelets is studied using the finite
element method with periodic representative volume element (RVE). A hybrid
2D/3D finite element mesh is used to reduce the computational complexity of the
numerical model. Several realizations of an RVE were generated with increasing
volume fractions of inclusions, resulting in progressive clusterization of the
platelets. Numerically obtained effective properties of the composite are
compared with analytical predictions by the Mori-Tanaka method and Halpin-Tsai
equations, and the limits of the applicability of the analytical models are
established. A two-step homogenization scheme is proposed to increase the
accuracy and stability of the effective properties of an RVE with a relatively
small number of inclusions. Simple scaling relations are proposed to generalize
numerical results to platelets with other aspect ratios.
