Abstract
Based on a three dimensional multiple slip crystalline formulation with dislocation density and computational scheme, the characteristics of grain boundaries (G.B.) of policrystalline metal are studied. To analyze the G.B. behavior in polycrystal, the direction of the most active slip system and its immobile dislocation density are considered at each G.B. It is shown that the fraction of some G.B.s orientation is one of the dominant issues to determine fracture mode of polycrystalline materials. The results show the polycrystal which includes Σ17b G.B. causes intergranular fracture more likely than the polycrystal which contains Σ33a G.B.
