Publications
225 results found
Cavarretta I, Coop M, O'Sullivan C, 2010, The influence of particle characteristics on the behaviour of coarse grained soils, GEOTECHNIQUE, Vol: 60, Pages: 413-423, ISSN: 0016-8505
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- Citations: 302
O'Sullivan C, Butlanska J, Cheung G, 2010, Calculating Strain in 3D DEM Simulations, 9th World Congress on Computational Mechanics/4th Asian Pacific Congress on Computational Mechanics, Publisher: IOP PUBLISHING LTD, ISSN: 1757-8981
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- Citations: 2
Fonseca J, O'Sullivan C, Coop MR, 2010, Quantitative Description of Grain Contacts in a Locked Sand, Proc. 3rd International Workshop on X-Ray CT for Geomaterials, GeoX 2010, Publisher: ISTE, Pages: 17-25
O'Sullivan C, Cui L, 2009, Micromechanics of granular material response during load reversals: Combined DEM and experimental study, Powder Technology, Vol: 193, Pages: 289-302
Donohue S, O'Sullivan C, Long M, 2009, Particle breakage during cyclic triaxial loading of a carbonate sand, GEOTECHNIQUE, Vol: 59, Pages: 477-482, ISSN: 0016-8505
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- Citations: 90
O'Sullivan C, Cui L, 2009, Fabric Evolution in Granular Materials Subject to Drained, Strain Controlled Cyclic Loading, 6th International Conference on the Micromechanics of Granular Media, Publisher: AMER INST PHYSICS, Pages: 285-+, ISSN: 0094-243X
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- Citations: 9
Fonseca J, O'Sullivan C, Coop MR, 2009, Image Segmentation Techniques for Granular Materials, 6th International Conference on the Micromechanics of Granular Media, Publisher: AMER INST PHYSICS, Pages: 223-226, ISSN: 0094-243X
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- Citations: 7
Barreto D, O'Sullivan C, Zdravkovic L, 2009, Quantifying the Evolution of Soil Fabric Under Different Stress Paths, 6th International Conference on the Micromechanics of Granular Media, Publisher: AMER INST PHYSICS, Pages: 181-184, ISSN: 0094-243X
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- Citations: 27
Cavarretta I, O'Sullivan C, Coop MR, 2009, Applying 2D shape analysis techniques to granular materials with 3D particle geometries, 6th International Conference on the Micromechanics of Granular Media, Publisher: AMER INST PHYSICS, Pages: 833-836, ISSN: 0094-243X
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- Citations: 34
O'Sullivan C, 2008, Particle-based discrete element modelling: A geomechanics overview, Pages: 498-505
Discrete element modelling (DEM) is an approach for the analysis of granular material response that explicitly considers the interaction between individual particles. With increasing computational speeds, the use of particle-based DEM is becoming more widespread amongst geotechnical engineers in both research and practice. This paper provides a brief overview of the theoretical basis for discrete element modelling. The practicalities of carrying out discrete element analyses are addressed, specifically considering boundary conditions, the risks associated with numerical instability, and some useful approaches that can be used to postprocess the vast quantities of data that emerge from DEM simulations. The limitations of our current DEM modelling capabilities are outlined and the likely trends for development of DEM codes in the near future are considered. The benefits of discrete element analyses to geotechnical engineers interested in the micromechanics of soil response are demonstrated by considering the results of simulations of both quasi-static soil mechanics element tests in two and three dimensions.
Cheung G, O'Sullivan C, 2008, Effective simulation of flexible lateral boundaries in two- and three-dimensional DEM simulations, PARTICUOLOGY, Vol: 6, Pages: 483-500, ISSN: 1674-2001
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- Citations: 85
O'Sullivan C, Cui L, O'Neill SC, 2008, DISCRETE ELEMENT ANALYSIS OF THE RESPONSE OF GRANULAR MATERIALS DURING CYCLIC LOADING, SOILS AND FOUNDATIONS, Vol: 48, Pages: 511-530, ISSN: 0038-0806
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- Citations: 80
Meejun N, Skeldon AC, Tuzun U, et al., 2008, Wavelet analysis of DEM simulations of samples under biaxial compression, GRANULAR MATTER, Vol: 10, Pages: 389-398, ISSN: 1434-5021
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- Citations: 2
Barreto D, O'Sullivan C, Zdravkovic L, 2008, Specimen generation approaches for DEM simulations, 4th International Symposium on Deformation Characteristics of Geomaterials, Publisher: I O S PRESS, Pages: 901-906
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- Citations: 1
Fonseca J, O'Sullivan C, 2008, A re-evaluation of the Fourier descriptor approach to quantifying sand particle geometry, 4th International Symposium on Deformation Characteristics of Geomaterials, Publisher: I O S PRESS, Pages: 687-693
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- Citations: 4
Cui L, O'Sullivan C, O'Neill S, 2007, An analysis of the triaxial apparatus using a mixed boundary three-dimensional discrete element model, GEOTECHNIQUE, Vol: 57, Pages: 831-844, ISSN: 0016-8505
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- Citations: 84
Kinloch H, O'Sullivan C, 2007, A micro-mechanical study of the influence of penetrometer geometry on failure mechanisms in granular soils, GeoDenver 2007 ASCE Geo Congress 2007
Cui L, O'Sullivan C, O'Neil S, 2007, Coupling DEM simulations and Physical Tests to Study the Load – Unload Response of an Ideal Granular Material, 4th International Conference on Discrete Element Methods
O'Sullivan C, Creed M, 2007, Using a virtual back in retaining wall design, PROCEEDINGS OF THE INSTITUTION OF CIVIL ENGINEERS-GEOTECHNICAL ENGINEERING, Vol: 160, Pages: 147-151, ISSN: 1353-2618
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- Citations: 3
O'Sullivan C, Bray JD, Cui L, 2006, Experimental validation of particle-based discrete element methods
As a consequence of its particulate nature, soil exhibits a highly complex response to applied loads and deformations. Traditionally, geotechnical engineers have coupled continuum numerical analysis tools (such as the finite element method) with complex constitutive models to analyze soil response. This approach does not explicitly consider the particle-scale interactions underlying the macro-scale response observed in the laboratory and field. With increasing computational speeds, particle-based discrete element methods are becoming popular amongst geotechnical engineers in both research and practice. On a practical level discrete element methods are particularly useful for studying finite deformation problems, while from a more theoretical perspective they can be used to create virtual laboratories where the micro-mechanics of soil response can be analyzed in detail. This paper describes a series of validation studies that were performed to confirm that, despite their inherent simplifications, discrete element methods can accurately capture the macro-scale response of granular materials. It is shown that, once validated, these methods can provide useful information to explain the complex response exhibited by granular materials in conventional laboratory tests. Copyright ASCE 2006.
Cui L, O'Sullivan C, 2006, Exploring the macro- and micro-scale response of an idealised granular material in the direct shear apparatus, Géotechnique, Vol: 56, Pages: 455-468, ISSN: 0016-8505
Cui L, O'Sullivan C, 2006, Exploring the macro- and micro-scale response of an idealised granular material in the direct shear apparatus, GEOTECHNIQUE, Vol: 56, Pages: 455-468, ISSN: 0016-8505
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- Citations: 173
Cui L, O’Sullivan C, 2005, Development of a mixed boundary environment for axi-symmetric DEM analyses, Rotterdam, Publisher: A.A. Balkema, Pages: 301-305
O’Sullivan C, Cui L, 2005, Three-Dimensional Discrete Element Simulations of Direct Shear Tests, 11th International Conference of IACMAG, Pages: 119-126
O’Sullivan C, Basu B, 2005, Distinct element analysis of base isolation with rolling rods, SECED Young Engineers Conference
O’Sullivan C, Bray JD, 2005, The Importance of Accurately Capturing Particle Geometry in DEM Simulations, Rotterdam, Powders & Grains 2005, Publisher: A.A. Balkema, Pages: 1333-1337
Carolan AM, O’Sullivan C, 2005, The Influence of Particle Crushing on Material Response in the Direct Shear Box using DEM, Proceedings 17th EYGEC conference
O’Sullivan C, Bray JD, 2005, Use of DEM to Analyse Incremental Strains along Localizations in Granular Materials, 16th International Conference on Soil Mechanics and Geotechnical Engineering
O'Sullivan C, Bray JD, Riemer M, 2004, Examination of the response of regularly packed specimens of spherical particles using physical tests and discrete element simulations, JOURNAL OF ENGINEERING MECHANICS, Vol: 130, Pages: 1140-1150, ISSN: 0733-9399
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- Citations: 42
O'Sullivan C, Bray JD, Riemer M, 2004, Examination of the response of regularly packed specimens of spherical particles using physical tests and discrete element simulations, Journal of Engineering Mechanics, Vol: 130, Pages: 1140-1150, ISSN: 0733-9399
Significant insight into the response of granular materials can be gained by coupling accurately controlled physical tests with complementary discrete element simulations. This paper discusses a series of triaxial and plane strain laboratory compression tests on steel spheres with face-centered-cubic and rhombic packings, as well as discrete element simulations of these tests. The tests were performed on specimens of uniform-sized steel balls and on specimens of steel balls with specified distributions of ball diameters. The packing configurations are ideal and differ considerably from real sand specimens, however, studies of such idealized granular materials can yield considerable insight into the response of granular materials and the capability of discrete element simulations to capture the response. The differences in response for the two packing configurations considered illustrate the importance of fabric. The numerical simulations captured the observed laboratory response well if the particle configurations, particle sizes, and boundary conditions were accurately represented. However, the postpeak response is more difficult to capture, and it is shown to be sensitive to the coefficient of friction assumed along the specimen boundaries. The simulations of the tests on the nonuniform-sized specimens demonstrated a clear correlation between strength and coordination number. © ASCE.
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