Abstract
For a type of functionally graded materials, volumetric fraction of particles varies continuously and extensively. In general, because particles are randomly distributed, it is difficult to accurately evaluate the properties and to adjust them. A concise evaluation of the properties is needed for material design. In the present paper, plates including an array of particles are dealt with and the relations between stress and strain under uniaxial tension are discussed. The plate specimens are made of epoxy resin and steel balls, with different volumetric fraction of steel balls. From the result of the tensile test, it is clarified the influence of volumetric fraction of balls on the stress-strain relations of the specimens. In addition, tangent coefficients of stress-strain curves are obtained and it is shown the change of the tangent coefficients with strain. The maximum tangent coefficients are compared with values obtained by Voigt's, Reuss' and the intermediate models. Also tangent coefficients at 0.5% stran are compared with values obtained by considering effective section.
