Discrete element simulation of railway ballast: modelling cell pressure effects in triaxial tests
Discrete element simulation of railway ballast: modelling cell pressure effects in triaxial tests
The paper investigates reproducing the effects of confining pressure on the behaviour of scaled railway ballast in triaxial tests in discrete element models (DEM). Previous DEM work, using a standard Hertzian elastic contact law with an elastic–perfectly plastic tangential slip model, has been unable to replicate the behaviour observed in laboratory tests across a range of confining pressures without altering both the material stiffness and the inter-particle friction. A new contact law modelling damage at the contacts between particles is introduced. Particle contact is via spherically-capped conical asperities, which reduce in height if over-stressed. This introduces plasticity to the behaviour normal to the contact surface. In addition, the inter-particle friction angle is varied as a function of normalized contact normal force. At relatively low normal forces the friction angle must be increased for peak mobilized friction angles to match the laboratory data, an effect that is attributed to interlocking at the scale of surface roughness. Simulation results show close agreement with laboratory data.
1-13
Harkness, John
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Zervos, Antonios
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Le Pen, Louis
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Aingaran, Sinthuja
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Powrie, William
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1 August 2016
Harkness, John
026f02e8-41d9-403f-83be-0d880058ecf1
Zervos, Antonios
9e60164e-af2c-4776-af7d-dfc9a454c46e
Le Pen, Louis
4a38e256-d113-4bba-b0d4-32d41995928a
Aingaran, Sinthuja
d1090eef-e035-43fb-8762-f0a600706911
Powrie, William
600c3f02-00f8-4486-ae4b-b4fc8ec77c3c
Harkness, John, Zervos, Antonios, Le Pen, Louis, Aingaran, Sinthuja and Powrie, William
(2016)
Discrete element simulation of railway ballast: modelling cell pressure effects in triaxial tests.
Granular Matter, 18 (3), , [65].
(doi:10.1007/s10035-016-0660-y).
Abstract
The paper investigates reproducing the effects of confining pressure on the behaviour of scaled railway ballast in triaxial tests in discrete element models (DEM). Previous DEM work, using a standard Hertzian elastic contact law with an elastic–perfectly plastic tangential slip model, has been unable to replicate the behaviour observed in laboratory tests across a range of confining pressures without altering both the material stiffness and the inter-particle friction. A new contact law modelling damage at the contacts between particles is introduced. Particle contact is via spherically-capped conical asperities, which reduce in height if over-stressed. This introduces plasticity to the behaviour normal to the contact surface. In addition, the inter-particle friction angle is varied as a function of normalized contact normal force. At relatively low normal forces the friction angle must be increased for peak mobilized friction angles to match the laboratory data, an effect that is attributed to interlocking at the scale of surface roughness. Simulation results show close agreement with laboratory data.
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article10.1007s10035-016-0660-y.pdf
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Accepted/In Press date: 5 May 2016
e-pub ahead of print date: 7 July 2016
Published date: 1 August 2016
Organisations:
Infrastructure Group
Identifiers
Local EPrints ID: 397977
URI: http://eprints.soton.ac.uk/id/eprint/397977
ISSN: 1434-5021
PURE UUID: 51258379-cd0c-4217-ba40-468e8eba96ec
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Date deposited: 13 Jul 2016 09:26
Last modified: 15 Mar 2024 03:24
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Author:
Sinthuja Aingaran
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