Large isotropic elastic deformation of composites and porous media

Abstract The problem of large isotropic deformation of composite materials and porous media consisting of a finitely-deforming elastic matrix and spherical inclusions or voids is analyzed exactly on the basis of the composite spheres assemblage model. For porous media, the stress strain relations for expansion and contraction are found to be fundamentally different. It is shown that a very small amount of pores has significant effect on expansion, but not on contraction.