A numerical investigation of the effect of particle shape on the strength of coarse granular materials
A numerical investigation of the effect of particle shape on the strength of coarse granular materials
It has long been recognised that the macroscopic mechanical behaviour of a granular material depends on particle shape. However, a systematic investigation into particle shape is lacking. There are three different aspect of shape each considering shape at a different scale, typically these are called form, angularity and roughness. The form of a particle can be quantified using the Longest (L), Intermediate (I) and Shortest (S) dimension of an equivalent scalene ellipsoid; two independent parameters of particle form are defined, termed platyness and elongation. The angularity of a particle can be quantified by the volumetric deviation between the true particle shape and the idealised equivalent scalene ellipsoid. This volume is then normalised against the original volume of the particle.
We used DEM simulations with the Potential Particle Method to investigate the effect of particle shape on the friction angle of a granular material at critical state. By studying particle form and angularity in isolation, it is found that deviation of particle form and angularity (from that of a sphere) leads to higher angles of friction at critical state. It is found that the higher critical state strength exhibited by non-spherical particles is due to form suppressing particle rotation and leading to increased interparticle sliding, a mechanism that in comparison requires more energy to be expended. It is found that for particles combining non-spherical form and angularity that both measures act cooperatively with regards to increasing the angle of friction at critical state. It is also seen that these two effects are not independent of each other as the effectiveness of particle angularity is dependant on the underlying form of the shape. This is possibly due to particle angularity increasing the effectiveness of mechanisms created due to different particle forms.
University of Southampton
Potticary, Matthew
2828c807-6a58-4861-a744-3c955749d2aa
Potticary, Matthew
2828c807-6a58-4861-a744-3c955749d2aa
Zervos, Antonios
9e60164e-af2c-4776-af7d-dfc9a454c46e
Potticary, Matthew
(2018)
A numerical investigation of the effect of particle shape on the strength of coarse granular materials.
University of Southampton, Doctoral Thesis, 133pp.
Record type:
Thesis
(Doctoral)
Abstract
It has long been recognised that the macroscopic mechanical behaviour of a granular material depends on particle shape. However, a systematic investigation into particle shape is lacking. There are three different aspect of shape each considering shape at a different scale, typically these are called form, angularity and roughness. The form of a particle can be quantified using the Longest (L), Intermediate (I) and Shortest (S) dimension of an equivalent scalene ellipsoid; two independent parameters of particle form are defined, termed platyness and elongation. The angularity of a particle can be quantified by the volumetric deviation between the true particle shape and the idealised equivalent scalene ellipsoid. This volume is then normalised against the original volume of the particle.
We used DEM simulations with the Potential Particle Method to investigate the effect of particle shape on the friction angle of a granular material at critical state. By studying particle form and angularity in isolation, it is found that deviation of particle form and angularity (from that of a sphere) leads to higher angles of friction at critical state. It is found that the higher critical state strength exhibited by non-spherical particles is due to form suppressing particle rotation and leading to increased interparticle sliding, a mechanism that in comparison requires more energy to be expended. It is found that for particles combining non-spherical form and angularity that both measures act cooperatively with regards to increasing the angle of friction at critical state. It is also seen that these two effects are not independent of each other as the effectiveness of particle angularity is dependant on the underlying form of the shape. This is possibly due to particle angularity increasing the effectiveness of mechanisms created due to different particle forms.
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Potticary Final Thesis
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Submitted date: December 2018
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Local EPrints ID: 456047
URI: http://eprints.soton.ac.uk/id/eprint/456047
PURE UUID: 5cbb4627-2d35-4e62-9906-945b2532b76a
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Date deposited: 25 Apr 2022 16:33
Last modified: 17 Mar 2024 07:16
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