DEM Capability

sartrouville rencontre libertine EPPIC is capable of running a large range of DEM models, from transfer chutes to mill grinding processes to ground engaging tools. Functionality includes:

  • Any number of arbitrary multi-sphere particle templates
  • Any number of arbitrary polyhedral particle templates
  • Particle solid density
  • Particle static and dynamic friction
  • Particle bonding model
  • Particle breakage model
  • Uniform and Rossin-Rammler mass distribution functions
  • Geometry import by STL file (easily exported from most CAD software)
  • Fixed, Free, or prescribed motion for user-instantiated geometries
  • Surface velocities on stationary surfaces for simulation of conveyors
  • Particle factories with prescribed template, distribution, and rate functions
  • Weightometer volumes for mass and flowrate output
  • Position, velocity, and total applied force output for user-instantiated geometries
  • On screen visualisation of model progress
  • VTK output file format for detailed post processing
  • Surface energy dissipation maps for particle normal impacts, sliding contact, and fluid impact

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    Internal friction

    To simulate bulk material flow requires that the model be able to reproduce the internal friction of the material, or angle of repose. This is sometimes measured with the slump test, and is a strong function of the choice of particle shape and friction coefficients.

     

    Surface velocities

    Transfer chute design also requires that the conveyor approach and discharge is also modelled. Conveyors may be modelled using a fixed-in-space geometry with an assigned tangential surface velocity parameter. EPPIC allows for the definition of scalar and vector parameters as a function of time, which may be selected as the input for factory rates, geometry motion and geometry surface velocity.

     

    Surface energy dissipation may be plotted by particle normal impact energy or particle sliding friction energy. transferChuteWear500x800

    Particle breakage

    Mill grinding processes can be simulated with a simple particle breakage model whereby particles clone into two once contact stresses exceed a threshold. Grinding efficacy, mill power predictions, and discharge chute adequacy may be investigated as a functions of material properties, ball load, mill speed and mill charge.

     

    Screening

    Particle handling and screening processes may be modelled. The animation below is of a trommel used to sieve out oversize particles.

     

    Bonding

    A simple particle bonding model may be selected to simulate consolidated materials, such as may occur in silos, rail wagons, and importantly for ground engaging tools, the ground. In this example the bonding forms once a particle to particle contact reaches a threshold age, allowing the material to flow into position and then set prior to the dozer blade engaging.

     

    The are many many more applications of DEM modelling. For more information regarding the suitability of EPPIC to your application please feel free to email Santa Barbara info@simphysics.com.au