Challenges in Continuum Modelling of Intergranular Fracture

Valerie Coffman, James P. Sethna, A. R. Ingraffea, J. E. Bozek, Nicholas Bailey, E. I. Barker

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

Intergranular fracture in polycrystals is often simulated by finite elements coupled to a cohesive zone model for the interfaces, requiring cohesive laws for grain boundaries as a function of their geometry. We discuss three challenges in understanding intergranular fracture in polycrystals. First, 3D grain boundary geometries comprise a five-dimensional space. Second, the energy and peak stress of grain boundaries have singularities for all commensurate grain boundaries, especially those with short repeat distances. Thirdly, fracture nucleation and growth depend not only upon the properties of grain boundaries, but also in crucial ways on edges, corners and triple junctions of even greater geometrical complexity. To address the first two challenges, we explore the physical underpinnings for creating functional forms to capture the hierarchical commensurability structure in the grain boundary properties. To address the last challenge, we demonstrate a method for atomistically extracting the fracture properties of geometrically complex local regions on the fly from within a finite element simulation.
Original languageEnglish
JournalStrain
Volume47
Issue numbers2
Pages (from-to)99-104
ISSN0039-2103
DOIs
Publication statusPublished - 2011

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