Defining the DEM Particles and their Interactions

You define solid DEM particles of spherical shape that interact with each other and with the walls of the excavator shovel and the domain. This interaction is governed by the Hertz Mindlin model.

To define the DEM particles:
  1. In the Physics 1 Model Selection dialog, in the model tree in the left-hand pane, right-click the Lagrangian Multiphase > Lagrangian Phases node and select New > Free-stream phase.
  2. Rename the Phase 1 node to Particles.
  3. In the dialog, select the following models, in order:
    Group Box Model
    Particle Type DEM Particles
    Particle Shape Spherical Particles
    Material Solid
  4. Create a phase interaction between the particles:
    1. In the model selection dialog, in the left-hand pane, right-click the Multiphase Interaction > Phase Interactions node and select New > Particles > Particles.
    2. Rename the Phase Interaction 1 node to Particles-Particles.
    3. In the right-hand side of the dialog, within DEM Contact Model, select Hertz Mindlin.
  5. Create a phase interaction between the particles and the wall:
    1. In the model selection dialog, in the left-hand pane, right-click the Multiphase Interaction > Phase Interactions node and select New > Particles > Wall.
    2. Rename the Phase Interaction 1 node to Particles-Wall.
    3. In the right-hand side of the dialog, within DEM Contact Model, select Hertz Mindlin.
  6. Click Close.
  7. In the physics model tree, within the Simulation window, expand the Continua > Physics 1 > Models > Lagrangian Multiphase > Lagrangian Phases > Particles > Models > Solid node and rename the Rubber node to Rock.
  8. Select the Rock > Material Properties > Young's Modulus > Constant node and set Value to 10.0 MPa.
  9. Set the properties of the Hertz Mindlin model for he Particles-Particles interaction:
    1. Select the Physics 1 > Models > Multiphase Interaction > Phase Interactions > Particles-Particles > Models > Hertz Mindlin node and set the following properties:
      Property Group
      Static Friction Coefficient 0.9
      Normal Restitution Coefficient 0.2
      Tangential Restitution Coefficient 0.2
    2. Select the adjacent Rolling Resistance > Rolling Resistance Methods node and set Method to Constant Torque.
    3. Select the Rolling Resistance Methods > Constant Torque node and set Coefficient of Rolling Resistance to 0.5.
  10. Set the properties of the Hertz Mindlin model for the Particles-Wall interaction:
    1. Select the Multiphase Interaction > Phase Interactions > Particles-Wall > Models > Hertz Mindlin node and set the following properties:
      Property Group
      Static Friction Coefficient 0.61
      Normal Restitution Coefficient 0.2
      Tangential Restitution Coefficient 0.2
    2. Select the adjacent Rolling Resistance > Rolling Resistance Methods node and set Method to Constant Torque.
    3. Select the Constant Torque node and set Coefficient of Rolling Resistance to 0.1.
  11. Save the simulation.