Abstract
Microscopic stress distribution in porous ceramics is important for fracture prediction of the material, because high stress concentration occurs in the complicated pore structure of the materials. To analyze the microscopic stress distribution, image-based modeling and homogenized calculation were carried out. The complicated 3-dimensional structure of the ceramic was imaged by a high-resolution X-ray CT. A small volume-data was took in a voxel mesh calculation as a representative volume element (RVE). Mathematical homogenization method was applied to the RVE, and homogenized elastic constants were calculated for the RVE. Using the homogenized elastic constants, macroscopic stress distribution was calculated with FEM for a global stress model of 4-point bending test. Maximum global tensile stress 100MPa was calculated. Using the value as the external stress applied to the microscopic RVE, the local microscopic stress distribution was analyzed. About 2~4 times larger stress concentration were found near the pores included.
