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Comparison of two different types of railway ballast in compression and direct shear tests: experimental results and DEM model validation

Railway ballast is an angular and coarse material, which demands careful DEM modelling and validation. Particle shape is often modelled in high accuracy, thus leading to computational expensive DEM models. Whether this effort will increase the DEM model’s overall prediction quality will also vitally...

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Detalles Bibliográficos
Autores principales: Suhr, Bettina, Marschnig, Stefan, Six, Klaus
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Springer Berlin Heidelberg 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6245121/
https://www.ncbi.nlm.nih.gov/pubmed/30532652
http://dx.doi.org/10.1007/s10035-018-0843-9
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author Suhr, Bettina
Marschnig, Stefan
Six, Klaus
author_facet Suhr, Bettina
Marschnig, Stefan
Six, Klaus
author_sort Suhr, Bettina
collection PubMed
description Railway ballast is an angular and coarse material, which demands careful DEM modelling and validation. Particle shape is often modelled in high accuracy, thus leading to computational expensive DEM models. Whether this effort will increase the DEM model’s overall prediction quality will also vitally depend on the used contact law and the validation process. In general, a DEM model validated using different types of principal experiments can be considered more trustworthy in simulating other load cases. Here, two types of railway ballast are compared and DEM model validation is conducted. Calcite and Kieselkalk are investigated under compression and direct shear test. All experimental data will be made openly accessible to promote further research on this topic. In the experiments, the behaviour of Calcite and Kieselkalk is surprisingly similar in the direct shear test, while clear differences can be seen in the stiffnesses in the compression test. In DEM modelling, simple particle shapes are combined with the Conical Damage Model contact law. For each type of ballast, one set of parameters is found, such that simulation and experimental results are in good accordance. A comparison with the simplified Hertz-Mindlin contact law shows several drawbacks of this model. First, the model cannot be calibrated to meet both compression and shear test results. Second, the similar behaviour in shear testing but differences in compression cannot be reproduced using the Hertz-Mindlin model. For these reasons, the CDM model is considered the better choice for the simulation of railway ballast, if simple particle shapes are used.
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spelling pubmed-62451212018-12-06 Comparison of two different types of railway ballast in compression and direct shear tests: experimental results and DEM model validation Suhr, Bettina Marschnig, Stefan Six, Klaus Granul Matter Original Paper Railway ballast is an angular and coarse material, which demands careful DEM modelling and validation. Particle shape is often modelled in high accuracy, thus leading to computational expensive DEM models. Whether this effort will increase the DEM model’s overall prediction quality will also vitally depend on the used contact law and the validation process. In general, a DEM model validated using different types of principal experiments can be considered more trustworthy in simulating other load cases. Here, two types of railway ballast are compared and DEM model validation is conducted. Calcite and Kieselkalk are investigated under compression and direct shear test. All experimental data will be made openly accessible to promote further research on this topic. In the experiments, the behaviour of Calcite and Kieselkalk is surprisingly similar in the direct shear test, while clear differences can be seen in the stiffnesses in the compression test. In DEM modelling, simple particle shapes are combined with the Conical Damage Model contact law. For each type of ballast, one set of parameters is found, such that simulation and experimental results are in good accordance. A comparison with the simplified Hertz-Mindlin contact law shows several drawbacks of this model. First, the model cannot be calibrated to meet both compression and shear test results. Second, the similar behaviour in shear testing but differences in compression cannot be reproduced using the Hertz-Mindlin model. For these reasons, the CDM model is considered the better choice for the simulation of railway ballast, if simple particle shapes are used. Springer Berlin Heidelberg 2018-09-29 2018 /pmc/articles/PMC6245121/ /pubmed/30532652 http://dx.doi.org/10.1007/s10035-018-0843-9 Text en © The Author(s) 2018 Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.
spellingShingle Original Paper
Suhr, Bettina
Marschnig, Stefan
Six, Klaus
Comparison of two different types of railway ballast in compression and direct shear tests: experimental results and DEM model validation
title Comparison of two different types of railway ballast in compression and direct shear tests: experimental results and DEM model validation
title_full Comparison of two different types of railway ballast in compression and direct shear tests: experimental results and DEM model validation
title_fullStr Comparison of two different types of railway ballast in compression and direct shear tests: experimental results and DEM model validation
title_full_unstemmed Comparison of two different types of railway ballast in compression and direct shear tests: experimental results and DEM model validation
title_short Comparison of two different types of railway ballast in compression and direct shear tests: experimental results and DEM model validation
title_sort comparison of two different types of railway ballast in compression and direct shear tests: experimental results and dem model validation
topic Original Paper
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6245121/
https://www.ncbi.nlm.nih.gov/pubmed/30532652
http://dx.doi.org/10.1007/s10035-018-0843-9
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