抄録
Plastic deformation of metallic material with elliptic inclusions was studied by assuming the material composed of rigid-plastic solid with different yield stress and using a plane model of material with the staggered configuration of inclusions. The rigid-plastic finite element method was employed in the numerical calculation which is based on the upper bound theory in plasticity. Uniaxial and biaxial tensile stresses were assumed to be applied to the model material under the plane stress condition. The calculation was made on both cases where the inclusions are harder than the matrix and softer than the matrix.
The influences of the aspect ratio, the yield stress ratio and the volume fraction of inclusions on the deformation behavior of the material were clarified. The deformation is much affected by the mutual restriction of deformation between the inclusion and the matrix. The mutual restriction is less under the biaxial applied stress than under the uniaxial stress. That is, the inclusion deforms independently from the matrix more under the biaxial tension than under the uniaxial tension. The mean flow stress of the material was also discussed based on the calculated strain distribution.
