Average elastic-plastic behavior of composite materials

A new approach to estimate the overall behavior of an inhomogeneous body is applied to investigate the average elastic-plastic state of composite materials in small deformation. The method is based on the concept of the average field of an infinite body with inhomogeneities, which is replaced by an equivalent body with homogeneous inclusions having appropriate eigenstrains that are composed of the actual plastic misfit strains and the properly determined eigenstrains by the equivalent replacement of the inhomogeneities. A simple example is given for a pure shear state of the elastic-perfectly plastic composite materials with spherical inhomogeneities. The overall hardening rate, quantitative estimate of ductility improvement, and unloading behavior are discussed.