The Application of Cohesive Elements in Numerical Simulations of the Intergranular Fracture in Voronoi Cellular Models

The 2D Voronoi algorithms were used for geometric modeling of crystalline grains. A cohesive interface model was used to simulate the process of grain-boundary separation. Polycrystalline aluminum was chosen as the research object. Under the condition of no defects while the uniaxial stretching load was applied, damage and failure of the grain boundaries as well as the stress distribution of the whole model were investigated. Based on this, a comparative study on grain-boundary damage and stress distribution was carried out in the case of defective while uniaxially stretched. It has been found that in the case of uniaxial stretch continuous failure elements appeared on the grain boundary perpendicular to the stretching direction, closest to the loading surface. This led to the formation of the so-called intergranular fracture ‘crack’. The simulation results showed that as the uniaxial tensile load increased the damage to the grain boundaries of polycrystalline aluminum would exacerbate. Due to the effect of number and distribution of the defects in grain boundaries on stress distribution of the entire model, different cohesive elements showed a different variation in stress value with the increase of the load.