Phase-Field Modelling of Crack Propagation in Anisotropic Polycrystalline Materials

Nowadays, products consisting of polycrystalline materials have been widely used in engineering applications, e.g. automobile and renewable energy. The macroscopic defects are generally strongly influenced by the fracture behavior of the polycrystalline materials at the meso- and microscopic level. In this paper, the proposed phase-field model for anisotropic fracture, which accounts for the preferential cleavage directions within each randomly oriented crystal, as well as an anisotropic material behavior with cubic symmetries, has been used to simulate the complex crack pattern in solar-grade polycrystalline silicon in a robust and straightforward manner. Furthermore, multi-field coupled finite element problems are performed with monolithic solution schemes. A representative numerical example for crack propagation in polycrystals is carried out. Finally, a summary of the numerical results in polycrystalline materials is presented and an outlook for next work steps is given.