R. Avazmohammadi - Graduate student, Department of Mechanical Engineering, Sharif University of Technology
R. Naghdabadi - Professor

In this paper a macroscopic (effective) constitutive relation for particulate composites with generally nonlinear elastic phases is obtained. The composites are made up of an irregular suspension of perfectly spherical inclusions, subjected to large deformation. A composite sphere element undergoing a tri-axial stretching deformation is used for homogenization process which leads to a macroscopic constitutive relation depending on the initial volume fraction of particles. The macroscopic stress and strain energy for some volume fractions are examined and compared to those of finite element results when the matrix and the inclusion are characterized by the incompressible and compressible neo-Hookean strain energies, respectively. Also, the effective moduli of the composite are compared with linear elastic cases at infinitesimal strain limit. The results are applicable to optimize the volume fraction of particles in light composites used in aerospace structures.

Particulate composites, Spherical particles, Macroscopic constitutive law, Hyperelasticity