Abstract
The fracture of ductile metallic material is caused by the voids in the material which grow and unite with each other when stress is applied to the material. In order to evaluate the damage of the material which includes voids, it is necessary to know the effect of the voids in the process of the fracture. In this study, the damage state of the ideal two dimensional model of porous material is evaluated by the equivalent net stress, which is calculated by the two different methods of constructing the unit cell. The validity of the procedure is checked by experiment of plane sheets with randomly distributed holes.
