Discrete element modeling

A simpler version of the discrete element model is the so-called trajectory model. In the trajectory approach, droplet field is modeled as a series of trajectories that emanate from the atomizer or a starting point. The coupling effects are included by summing the heat release to and the drag force on the gas phase. This approach can be used for steady dilute flows. 

Todorov, I.T., and W. Smith. 2004. DL POLY 3 The CCP5 national UK code formolecular-dynamics simulations. One contribution of 12 to a theme Discrete element modelling Methods and applications in the environmental sciences. Phil. Trans. R. Soc. Lond. A 362 1835-1852. 

The relationship between the structure of the disordered heterogeneous material (e.g., composite and porous media) and the effective physical properties (e.g., elastic moduli, thermal expansion coefficient, and failure characteristics) can also be addressed by the concept of the reconstructed porous/multiphase media (Torquato, 2000). For example, it is of great practical interest to understand how spatial variability in the microstructure of composites affects the failure characteristics of heterogeneous materials. The determination of the deformation under the stress of the porous material is important in porous packing of beds, mechanical properties of membranes (where the pressure applied in membrane separations is often large), mechanical properties of foams and gels, etc. Let us restrict our discussion to equilibrium mechanical properties in static deformations, e.g., effective Young s modulus and Poisson s ratio. The calculation of the impact resistance and other dynamic mechanical properties can be addressed by discrete element models (Thornton et al., 1999, 2004). 

Let us first consider the catalyst/polyolefin particle in the early stage of its evolution. The particle consists of the solid catalyst carrier with catalyst sites immobilized on its surface, polymer phase, and pores. The first-principle-based meso-scopic model of particle evolution has to be capable of describing the formation of polymer at catalyst sites, transport of monomer(s) and other re-actants/diluents through the polymer and pore space, and deformation of the polymer and catalyst carrier (including its fragmentation). Similar discrete element modeling techniques have been applied previously to different problems (Heyes et al., 2004 Mikami et al., 1998 Tsuji et al., 1993). 

Pandey, P, Song, Y., Kayihan, F., and Turton, R. (2006), Simulation of particle movement in a pan coating device using discrete element modeling and its comparison with videoimaging experiments, Powder Technol., 161,79-88. 

There have been some attempts to overcome the analysis of compaction problems, mostly by introducing numerical modeling approaches. The modeling approaches often used in compaction analysis are (a) phenomenological continuum models, (b) micromechanically based continuum models, and (c) discrete-element models. The parameters that should be analyzed when tableting is under development are as follows ... 

Gethin DT, Ransing RS, Lewis RW, et al. Numerical comparison of a deformable discrete element model and an equivalent continuum analysis for the compaction of ductile porous material. Comput Struct 2001 79 1287-1294. 

C.-W. Hong and P. Greil, Discrete Element Modelling of Colloidal Powder Processing, Ceramic Transactions, Vol. 54 Science, Technology, and Applications of Colloidal Suspension, American Ceramic Society, (1995) pp. 235-249. 

C.-W. Hong, Discrete Element Modelling of Colloidal Packing Dynamics During Centrifugal Casting, J. of the Ceramic Society of Japan, 104[9] 793-795 (1996). 

The Discrete Element Model (DEM) (Bicanic 2004) is a numerical method on the micro scale. It is an explicit dynamic numerical method for the solution of interacting particle systems. Continuum properties are obtained by the cumulative behaviour of a large number of particles with short range interactions (Bicanic... 

Another two-dimensional, discrete element model was applied by Cartaxo and Rocha [43]. In this work, only the dynamic phenomena were investigated, that is, heat and mass transfer between the phases were not considered. Thns, the inflnence of the momentum coupling between the discrete particles and the conveying air on the air radial velocity and the mass concentration profiles was presented. An object-oriented numerical model was developed to simulate the conveying of large spherical particles (3 mm) through 9.14 m vertical tube with 7.62 cm bore size. 

Sitharam, T. G. (2003). Discrete element modeling of cyclic behaviour of granular materials. Geotechnical and Geological Engineering, 21,297-329. doi 10.1023/ B GEGE.0000006036.00597.0b... 

Calio I, Marietta M, Panto B (2012) A new discrete element model for evaluation of the seismic behaviour of unreinforced masonry buildings. Eng Struct 40 327—338 Degee H, Lascar L (201 la) Cyclic shear behaviour of clay masonry walls - Part 1 walls including acoustic devices or with a door opening. Research report, Departement Argenco, Univerisity of... 

The pure soil sample is a quarter size of the other two S-RM samples, it is tested under 100 kPa, 200 kPa and 300 kPa confining pressure in the biaxial numerical simulation to verify the selection of soil particles calculation parameters in the discrete element model are corresponding with the macro-mechanical parameters of soil. The internal friction angle and cohesion force can be calculated through the three experiments. 

Wang, J, et al. 2011. Particle shape effects in discrete element modeling of cohesive angular particles. Granular Matter 13 1-12. 

Yan, B.C. et al. 2010. Three-dimensional ellipsoidal discrete element modeling of granular materials and its coupling with finite element facets. Modeling of Granular Materials 27(4) 519-550. 

Cordelair, J. Greil, P. (2004) Discrete element modeling of solid formation during electrophoretic deposition. Journal of Materials Science 39, 1017-1021. 

Goldschmidt, M. J. V., Kuipers, J. A. M., 2003. Discrete element modelling of fluidised bed spray granulation. Powder Technol. 138 39-45. 

Wallmersperger T, Wittel FK, D Ottavio M, Kroplin B (2008) Multiscale modeling of polymer gels - chemo-electric model versus discrete element model. Mech Adv Mater Struct 15(3-4) 228-234... 

Lemos JV (2007) Discrete element modeling of masonry structures. Int J Archit Herit 1(2) 190-213 Lourenfo PB (1996) A matrix formulation for the elastoplastic homogenisation of layered materials. Mech Cohes-Frict Mater 1 273-294 Lourenfo PB (2000) Anisotropic sohening model for masonry plates and shells. J Struct Eng 126(9) 1008-1016... 

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