Experimental investigation of particle contact laws for discrete element model of granular materials

AbstractWe present a version of the Discrete Element Method considering the particles as rigid polyhedra. The Principle of Virtual Work is employed as basis for a multibody dynamics model. Each particle surface is split into sub-regions, which are tracked for contact with other sub-regions of neighboring particles. Contact interactions are modeled pointwise, considering vertex-face, edge-edge, vertex-edge and vertex-vertex interactions. General polyhedra with triangular faces are considered as particles, permitting multiple pointwise interactions which are automatically detected along the model evolution. We propose a combined interface law composed of a penalty and a barrier approach, to fulfill the contact constraints. Numerical examples demonstrate that the model can handle normal and frictional contact effects in a robust manner. These include simulations of convex and non-convex particles, showing the potential of applicability to materials with complex shaped particles such as sand and railway ballast.

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A discrete-element model for viscoelastic deformation and fracture of glacial ice

Computer Physics Communications ◽

10.1016/j.cpc.2015.04.009 ◽

2015 ◽

Vol 195 ◽

pp. 14-22 ◽

Cited By ~ 12

Author(s):

T.I. Riikilä ◽

T. Tallinen ◽

J. Åström ◽

J. Timonen

Keyword(s):

Element Model ◽

Discrete Element ◽

Discrete Element Model ◽

Viscoelastic Deformation ◽

Glacial Ice ◽

Deformation And Fracture

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Study on Machining Mechanism of Glass Using Discrete Element Method

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.577.108 ◽

2014 ◽

Vol 577 ◽

pp. 108-111 ◽

Cited By ~ 1

Author(s):

Ying Qiu ◽

Mei Lin Gu ◽

Feng Guang Zhang ◽

Zhi Wei

Keyword(s):

Discrete Element Method ◽

Element Model ◽

Discrete Element ◽

Rake Angle ◽

Milling Process ◽

Micro Milling ◽

Discrete Element Model ◽

Machined Surface ◽

Damage Depth ◽

Element Method

The discrete element method (DEM) is applied to glass micromachining in this study. By three standard tests the discrete element model is established to match the main mechanical properties of glass. Then, indentating, cutting, micro milling process are simulated. Results show that the vertical damage depth is prevented from reaching the final machined surface in cutting process. Tool rake angle is the most remarkable factor influencing on the chip deformation and cutting force. The final machined surface is determined by the minimum cutting thickness per edge. Different cutting thickness, cutter shape and spindle speed largely effect on the mechanism of glass.

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Reduced Rough-Surface Parametrization for Use With the Discrete-Element Model

Journal of Turbomachinery ◽

10.1115/1.2952379 ◽

2009 ◽

Vol 131 (2) ◽

Cited By ~ 5

Author(s):

Stephen T. McClain ◽

Jason M. Brown

Keyword(s):

Heat Transfer ◽

Rough Surface ◽

Surface Characterization ◽

Rough Surfaces ◽

Roughness Element ◽

Three Dimensional ◽

Element Model ◽

Discrete Element ◽

Diameter Distribution ◽

Discrete Element Model

The discrete-element model for flows over rough surfaces was recently modified to predict drag and heat transfer for flow over randomly rough surfaces. However, the current form of the discrete-element model requires a blockage fraction and a roughness-element diameter distribution as a function of height to predict the drag and heat transfer of flow over a randomly rough surface. The requirement for a roughness-element diameter distribution at each height from the reference elevation has hindered the usefulness of the discrete-element model and inhibited its incorporation into a computational fluid dynamics (CFD) solver. To incorporate the discrete-element model into a CFD solver and to enable the discrete-element model to become a more useful engineering tool, the randomly rough surface characterization must be simplified. Methods for determining characteristic diameters for drag and heat transfer using complete three-dimensional surface measurements are presented. Drag and heat transfer predictions made using the model simplifications are compared to predictions made using the complete surface characterization and to experimental measurements for two randomly rough surfaces. Methods to use statistical surface information, as opposed to the complete three-dimensional surface measurements, to evaluate the characteristic dimensions of the roughness are also explored.

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