Fracture ab initio: A force-based scaling law for atomistically informed continuum models

Möller J, Bitzek E, Janisch R, ul Hassan H, Hartmaier A (2018)

Publication Language: English

Publication Status: Published

Publication Type: Journal article, Original article

Publication year: 2018

Journal

Journal of Materials Research Springer / Materials Research Society

Publisher: CAMBRIDGE UNIV PRESS

Book Volume: 33

Pages Range: 3750-3761

Journal Issue: 22

URI: https://www.cambridge.org/core/journals/journal-of-materials-research/article/fracture-ab-initio-a-forcebased-scaling-law-for-atomistically-informed-continuum-models/077AFC469E3C82F3D1A537EA83AEF5F6#

DOI: 10.1557/jmr.2018.384

Open Access Link: https://www.cambridge.org/core/journals/journal-of-materials-research/article/fracture-ab-initio-a-forcebased-scaling-law-for-atomistically-informed-continuum-models/077AFC469E3C82F3D1A537EA83AEF5F6#

Abstract

In fracture mechanics, established methods exist to model the stability of a crack tip or the kinetics of crack growth on both the atomic and the macroscopic scale. However, approaches to bridge the two scales still face the challenge in terms of directly converting the atomic forces at which bonds break into meaningful continuum mechanical failure stresses. Here we use two atomistic methods to investigate cleavage fracture of brittle materials: (i) we analyze the forces in front of a sharp crack and (ii) we study the bond breaking process during rigid body separation of half crystals without elastic relaxation. The comparison demonstrates the ability of the latter scheme, which is often used in ab initio density functional theory calculations, to model the bonding situation at a crack tip. Furthermore, we confirm the applicability of linear elastic fracture mechanics in the nanometer range close to crack tips in brittle materials. Based on these observations, a fracture mechanics model is developed to scale the critical atomic forces for bond breaking into relevant continuum mechanical quantities in the form of an atomistically informed scale-sensitive traction separation law. Such failure criteria can then be applied to describe fracture processes on larger length scales, e.g., in cohesive zone models or extended finite element models.

Authors with CRIS profile

Johannes Möller Lehrstuhl für Werkstoffwissenschaften (Allgemeine Werkstoffeigenschaften) Erik Bitzek Lehrstuhl für Werkstoffwissenschaften (Allgemeine Werkstoffeigenschaften)

Additional Organisation(s)

Lehrstuhl für Werkstoffwissenschaften (Allgemeine Werkstoffeigenschaften) Professur für Datenbasierte Materialmodellierung

Related research project(s)

Microscopic Origins of Fracture Toughness (microKlc) Microscopic Origins of Fracture Toughness May 1, 2017 - April 30, 2022 Atomistic simulations of elementary dislocation processes in coherent and semi-coherent y/y'-microstructures (C03) (SFB/TRR 103) TRR 103: Vom Atom zur Turbinenschaufel - wissenschaftliche Grundlagen für eine neue Generation einkristalliner Superlegierungen Jan. 1, 2012 - Dec. 31, 2019

Involved external institutions

Ruhr-Universität Bochum (RUB) DE Germany (DE)

How to cite

APA:

Möller, J., Bitzek, E., Janisch, R., ul Hassan, H., & Hartmaier, A. (2018). Fracture ab initio: A force-based scaling law for atomistically informed continuum models. Journal of Materials Research, 33(22), 3750-3761. https://doi.org/10.1557/jmr.2018.384

MLA:

Möller, Johannes, et al. "Fracture ab initio: A force-based scaling law for atomistically informed continuum models." Journal of Materials Research 33.22 (2018): 3750-3761.

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