NUMERICAL ANALYSIS OF FRACTURE BEHAVIOR IN ANISOTROPIC MICROSTRUCTURES

摘要

In order to examine the microstructural fracture behavior in the advanced multifunctional materials, a finite element method with the interface element was developed, where the anisotropy of grain was modeled by the ordinary finite element while both the opening and shear deformations at grain boundary were demonstrated by the interface element. By using virtual polycrystalline models obtained through Voronoi tessellations, the applicability of this method was studied. As the results assuming the influence of grain orientation on the grain boundary, it was found that the anisotropic mechanical property of grain boundary (interaction between opening and slipping deformations) would be a dominant factor of the fracture process. Also, by employing the theory of crystal plasticity for the mechanical property of grain, it was revealed that the stress concentrations caused by both the mismatch between neighbor grains and the slipping at grain boundary could be demonstrated by using this method. Finally, it can be concluded that this method would be a useful tool for examining microstructural fracture behavior.