Identifying a machine-learning structural descriptor linked to the creep behavior of Kob-Andersen glasses

A wide variety of materials, ranging from metals to concrete, experience, typically at high-temperatures or over long time scales, permanent deformations when subjected to sustained loads below their yield stress—a phenomenon known as creep. While theories grounded on defects such as vacancies, disl...

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Main Authors: Mingyue Wu, Luis Ruiz Pestana
Format: Article
Language:English
Published: Frontiers Media S.A. 2023-09-01
Series:Frontiers in Materials
Subjects:
Online Access:https://www.frontiersin.org/articles/10.3389/fmats.2023.1272355/full
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author Mingyue Wu
Luis Ruiz Pestana
author_facet Mingyue Wu
Luis Ruiz Pestana
author_sort Mingyue Wu
collection DOAJ
description A wide variety of materials, ranging from metals to concrete, experience, typically at high-temperatures or over long time scales, permanent deformations when subjected to sustained loads below their yield stress—a phenomenon known as creep. While theories grounded on defects such as vacancies, dislocations, or grain boundaries can explain creep in crystalline materials, our understanding of creep in disordered solids remains incomplete due to the lack of analogous structural descriptors. In this study, we use molecular dynamics to simulate the creep response of a Kob-Andersen glass model system under constant, uniaxial, compressive stress at finite temperature. We leverage that data to derive, using a machine-learning classification model, a structural descriptor termed looseness, L, which is based on simple and interpretable local structural features and can predict imminent plastic rearrangements within the glass. We show that the average looseness of the system evolves logarithmically with time, mirroring the time dependence of the creep strain and demonstrating the ability of our model to bridge local, short-term particle dynamics with the long-term macroscopic creep response. A detailed feature importance analysis reveals the particular significance of short-range structural heterogeneity in the prediction. We also scrutinize the spatial and temporal correlations of looseness, which mirror the lack of long-range order in glasses and their dynamic heterogeneity. Our research underscores the substantial predictive potential of machine-learning-derived structural indicators in systems experiencing concurrent stress and thermal excitations, paving the way for future work to elucidate the interplay between thermal and mechanical activation of structural defects in disordered solids.
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spelling doaj.art-4d6df08fda2f4881a76a2feb8fcf554f2023-09-13T06:33:55ZengFrontiers Media S.A.Frontiers in Materials2296-80162023-09-011010.3389/fmats.2023.12723551272355Identifying a machine-learning structural descriptor linked to the creep behavior of Kob-Andersen glassesMingyue WuLuis Ruiz PestanaA wide variety of materials, ranging from metals to concrete, experience, typically at high-temperatures or over long time scales, permanent deformations when subjected to sustained loads below their yield stress—a phenomenon known as creep. While theories grounded on defects such as vacancies, dislocations, or grain boundaries can explain creep in crystalline materials, our understanding of creep in disordered solids remains incomplete due to the lack of analogous structural descriptors. In this study, we use molecular dynamics to simulate the creep response of a Kob-Andersen glass model system under constant, uniaxial, compressive stress at finite temperature. We leverage that data to derive, using a machine-learning classification model, a structural descriptor termed looseness, L, which is based on simple and interpretable local structural features and can predict imminent plastic rearrangements within the glass. We show that the average looseness of the system evolves logarithmically with time, mirroring the time dependence of the creep strain and demonstrating the ability of our model to bridge local, short-term particle dynamics with the long-term macroscopic creep response. A detailed feature importance analysis reveals the particular significance of short-range structural heterogeneity in the prediction. We also scrutinize the spatial and temporal correlations of looseness, which mirror the lack of long-range order in glasses and their dynamic heterogeneity. Our research underscores the substantial predictive potential of machine-learning-derived structural indicators in systems experiencing concurrent stress and thermal excitations, paving the way for future work to elucidate the interplay between thermal and mechanical activation of structural defects in disordered solids.https://www.frontiersin.org/articles/10.3389/fmats.2023.1272355/fullcreepmolecular dynamicsmachine learningglassdisordered solid
spellingShingle Mingyue Wu
Luis Ruiz Pestana
Identifying a machine-learning structural descriptor linked to the creep behavior of Kob-Andersen glasses
Frontiers in Materials
creep
molecular dynamics
machine learning
glass
disordered solid
title Identifying a machine-learning structural descriptor linked to the creep behavior of Kob-Andersen glasses
title_full Identifying a machine-learning structural descriptor linked to the creep behavior of Kob-Andersen glasses
title_fullStr Identifying a machine-learning structural descriptor linked to the creep behavior of Kob-Andersen glasses
title_full_unstemmed Identifying a machine-learning structural descriptor linked to the creep behavior of Kob-Andersen glasses
title_short Identifying a machine-learning structural descriptor linked to the creep behavior of Kob-Andersen glasses
title_sort identifying a machine learning structural descriptor linked to the creep behavior of kob andersen glasses
topic creep
molecular dynamics
machine learning
glass
disordered solid
url https://www.frontiersin.org/articles/10.3389/fmats.2023.1272355/full
work_keys_str_mv AT mingyuewu identifyingamachinelearningstructuraldescriptorlinkedtothecreepbehaviorofkobandersenglasses
AT luisruizpestana identifyingamachinelearningstructuraldescriptorlinkedtothecreepbehaviorofkobandersenglasses