Abstract
Inhomogeneous material, tri-axial deformation of especially powder sintered materials and metal composite material was analyzed. The materials model proposed it as the materials which became the materials center from the thing which had spherical pore or the second phase. The admissible velocity fields in the matrix is assumed and the upper bound approach is attempted. The yield surfaces for various volume fraction Vf was obtained as a change of ellipsoids for increase of Vf.
Furthermore, the strength and deformation behavior of powder sintered materials and the metallic composite materials are investigated by the upper bound approach in relation to the volume fraction Vf of the second-phase particles, and the yield strength ratio and bond strength between the constituents, and the shape of the particles and pore.
