Computer simulation of microstructures and processes of granular composites fracture taking into account the influence of grain boundaries

The paper presents the algorithm for computer simulation of polycrystalline material microstructures with explicitly distinguished grain boundaries. The algorithm is based on the procedure of “growing” structure grains from ellipses, the geometric parameters of which can be set according to different laws of statistical distribution. The grain boundaries of the given thickness are formed from the original granular structure by displacing the boundaries inside the grain. The advantage of the presented algorithm is the possibility of obtaining nonlinear grain boundaries of different thicknesses, the width of which can be specified according to various statistical distribution laws. Polycrystalline material microstructure generation results that contain more than 100 structural elements and have a grain boundary fraction of up to 20 % are presented. New data on computer simulation of the deformation process and fracture of simulated granular materials are presented with different ratios of strength characteristics of grains and grain boundaries. It was revealed that, depending on the strength characteristics ratio value, different fracture mechanisms are realized in the material: intercrystalline, transcrystalline, and mixed forms of fracture.