Plastic Behavior of Some Composite Materials*

Abstract

Based on the simplest deformation theory of plasticity, an attempt is made to predict the overall plastic behavior of two-phase reinforced composites under polyaxial stresses. An ideal composite is considered in which the inclusions are rigid and the matrix is a power-law work- hardening material; it is hoped that such a model may adequately describe a composite comprised of elastic inclusions and an elastic- plastic matrix when the plastic strain is sufficiently large. The theory is developed by considering a two-phase isotropic composite under polyaxial stresses; and with the use of the self-consistent scheme, a detailed result is obtained for a unidirectional fibrous reinforced com posite under transverse stresses. With the introduction of the elastic behavior predicted by the self-consistent model, a semi-empirical prediction of the overall transverse elastic-plastic uniaxial stress-strain curve over the full strain range is made for a unidirectional fibrous reinforced composite comprised of rigid fibers and an elastic-plastic matrix.