Abstract
Understanding the mechanics and failure of materials at the nanoscale is critical for their engineering and applications. The accurate atomistic modeling of brittle failure with crack propagation in covalent crystals requires a quantum mechanics-based description of individual bond-breaking events. Artificial neural network potentials (NNPs) have emerged to overcome the traditional, physics-based modeling tradeoff between accuracy and accessible time and length scales. Previous studies have shown successful applications of NNPs for describing the structure and dynamics of molecular systems and amorphous or liquid phases of materials. However, their application to deformation and failure processes in materials is still uncommon. In this study, we discuss the apparent limitations of NNPs for the description of deformation and fracture under loadings and propose a way to generate and select training data for their employment in simulations of deformation and fracture simulations of crystals. We applied the proposed approach to 2D crystalline graphene, utilizing the density-functional tight-binding method for more efficient and extensive data generation in place of density functional theory. Then, we explored how the data selection affects the accuracy of the developed artificial NNPs. It revealed that NNP’s reliability should not only be measured based on the total energy and atomic force comparisons for reference structures but also utilize comparisons for physical properties, e.g. stress-strain curves and geometric deformation. In sharp contrast to popular reactive bond order potentials, our optimized NNP predicts straight crack propagation in graphene along both armchair and zigzag (ZZ) lattice directions, as well as higher fracture toughness of ZZ edge direction. Our study provides significant insight into crack propagation mechanisms on atomic scales and highlights strategies for NNP developments of broader materials.
Original language | English |
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Article number | 035001 |
Journal | Machine Learning: Science and Technology |
Volume | 4 |
Issue number | 3 |
DOIs | |
State | Published - Sep 1 2023 |
Funding
** Notice: This manuscript has been authored by UT-Battelle, LLC, under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a nonexclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan ( http://energy.gov/downloads/doe-public-access-plan ). The authors acknowledge helpful comments and discussion with J Warner. G S J and S I acknowledge support by the U. S. Department of Energy Fossile Energy and Carbon Management Program, Advanced Coal Processing Program, C4WARD project (FWP No. FEAA155). G S J acknowledges support for method developments by the Laboratory Directed Research and Development (LDRD), Eugene P Wigner Fellowship, Program of Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for the US Department of Energy. S I acknowledges partial support from the Artificial Intelligence Initiative as part of the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory. This research used resources of the Compute and Data Environment for Science (CADES) at the Oak Ridge National Laboratory, which is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC05-00OR22725.
Funders | Funder number |
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Advanced Coal Processing Program | FEAA155 |
Artificial Intelligence Initiative | |
CADES | |
Data Environment for Science | |
U. S. Department of Energy Fossile Energy and Carbon Management Program | |
U.S. Department of Energy | DE-AC05-00OR22725 |
Office of Science | |
Oak Ridge National Laboratory | |
Laboratory Directed Research and Development |
Keywords
- 2D materials
- crack propagation
- fracture
- graphene
- mechanics
- neural network potential