Computer-Aided Study of Materials’ Microstructure Influence on Cracks' Propagation Pattern in Brittle Anisotropic Bodies

The purpose of the presented study is a solution of a boundary-value problem, a visualization and a study of crack propagation pattern of a plane specimen of an anisotropic brittle material by computer modeling method. As main software for the research, MSC Nastran finite-element analysis package is used. As a result of the presented study, a methodology for a creation of finite-element models of various structural constituents and specimens with consideration of material’s microstructure is developed. Developed methodology is tested during the creation of finite-element model of the specimen assigned for a fracture with stress concentrators of varying forms and with a consideration of hypothetical structure, consisting of three types of crystallite with different mechanical properties. The methodology is proposed for an evaluation of kinetics and visualization of the crack growth in models of isotropic and anisotropic brittle materials. As the result of step-by-step visualization of the crack growth, animation files in AVI-format are created, which allow us to analyze the process of the material fracture. A theoretical equation is proposed for determination of the crack growth trajectory, which defines a relationship between a work needed for the crack growth and stresses in the specimen and its geometric parameters. An influence of the material on the trajectory of the crack growth is determined. Results of the presented study can serve as a tool for development of new materials with a high crack resistance due to their optimal microstructure. Developed methodologies allow you to determine desired location, size, shape of grains and their mechanical properties in microstructure of created material, without fabrication of many expensive full-size specimens.