Methods for Microstructure Modeling and Phase Field Simulations of Fracture

Author(s):

R Brian Leavy, John D Clayton, Jonathan P Ligda, and Jaroslaw Knap

Abstract:

Tools for modeling fracture and other structural transformation processes in polycrystalline materials are developed. Methods for construction of 3-D realizations of polycrystalline microstructures using experimental characterization data are described. Underlying statistics are discussed, and a workflow from statistical descriptors of microstructure to geometric rendering to finite element (FE) meshes is demonstrated. A formulation of the phase field method (PFM) with order parameter kinetics for transient processes is presented. This formulation is implemented in FE software with a unique implicit integration of the phase field kinetic equation. Simulations of fracture of ceramic polycrystals demonstrate the utility of the tools developed for synthetic microstructure generation and the effectiveness of the implicit dynamic implementation of the PFM. Results quantify effects of variations of initial microstructure features on dynamic tensile strength of polycrystals. Larger tensile strengths predicted by simulations relative to experiments are reconciled by Weibull scaling.