Voronoi Simulation of Creep Damage Evolution of Polycrystalline Materials.

Abstract

Creep damage modeling from the combined viewpoints of macroscopic and microscopic levels is proposed. A damage variable of a second-rank tensor for each material point is defined by the cavity microstructure of the grain aggregate simulated by the Voronoi tessellation. The damage evolution is calculated from the nucleation and growth of the grain boundary cavities using physically based equations. Furthermore, the effects of creep damage on mechanical behavior are treated at the macroscopic level by the damage mechanics formulation. The results of the analysis show that the rate of the damage evolution decreases at the final stage of damage.