PARAMETRIC DESCRIPTION OF ELASTIC-PLASTIC DEFORMATION-BEHAVIOR OF INHOMOGENEOUS MATERIAL WITH INCLUSIONS

The macroscopic elastic-plastic constitutive relation of inhomogeneous material is affected not only by the characteristics of respective co nstituents, but also by the microscopic distribution of stress and str ain in heterogeneous regions. In order to describe the deformation beh aviour of inhomogeneous material, several parameters are defined. A pl ane model of inhomogeneous material with inclusions is used for numeri cal simulation, and the changes in the parameters during elastic-plast ic deformation are calculated and compared. Uniaxial loading under the plane-strain condition is assumed. It is concluded that the initial a spect ratio has a marked influence on the deformation behaviour. One o f the parameters, called the constraint ratio, remains nearly constant with increase in the applied strain or the degree of inhomogeneity. T his characteristic seems to be important for estimating the deformatio n behaviour of inhomogeneous material. The constitutive relation oi in homogeneous material may also be estimated from the value of the const raint ratio.