EFFECTIVE ELASTIC-MODULI OF POROUS CERAMIC MATERIALS

This paper compares the applicability of a few theoretical models for determining effective elastic moduli, using published experimental dat a on ceramic materials in a porosity range of 0.40% and on a cellular material with a porosity of about 90%. As the experimental data for th e effective Poisson's ratio involve a large scatter, a set of numerica l experiments using the finite element method was carried out to obtai n the variation of the effective Poisson's ratio with porosity. These variations show that the effective Poisson's ratio approaches 0.25 wit h increasing porosity, irrespective of the material Poisson's ratio. T he effect of pore shapes on the effective elastic moduli and the Poiss on's ratio has also been analyzed using FEM.