EDEM Creator - Set up the Model

Learn how to set up a simulation model and equipment, and define the generation of bulk materials using EDEM Creator.

To set up the model:
  1. Select the units of measurement to be used throughout EDEM.
    For more information about how to select units, see Select Units.
    1. Click Tools > Options... and then select the Units tab.
    2. In the Units tab, change the following measurement units:
      • Velocity to m/s
      • Length to mm
    3. Click OK.
  2. Specify a title and description for the model.
    1. Click Project in the Creator Tree.
    2. In the Detailed View, specify a title (Tablet Press).
    3. Enter a description in the Description field.
    The model title and description is displayed in the Data Browser window. You can close the Data Browser window to allocate more space for the windows that will be used throughout this tutorial. If required, you can open the Data Browser window again by right-clicking the menu bar and selecting Data Browser.

Define the Bulk Material

The first step in setting up the model is to add bulk material and bulk material particle shapes to a model and define their interactions.

To define the bulk material:
  1. Add the bulk material.
    1. Right-click Bulk Material in the Creator Tree, select Add Bulk Material , and enter the name Powder in the BulkMaterial1 highlighted field. Alternatively, you can also use the icons in the Toolbar.
  2. Define the bulk material properties and interactions.
    1. Select Powder in the Bulk Material section.


    2. In the Particle Material Properties dialog box, specify the Poisson's Ratio, Solids Density, and Shear Modulus.
  3. Define the bulk material interactions.
    1. In the Interactions section, click the icon.
    2. In the Select Material dialog box, select Powder from the dropdown list to define the interaction between all elements made of the material 'Powder'.
    3. Specify the Coefficients as follows:


  4. Create a new particle shape after defining the bulk material and interaction properties.
    1. Right-click Powder in the Bulk Material section and then select Add Particle > Add Multi-Sphere.
    2. Enter the name 'PowderParticle' in the Particle highlighted field.

      Optionally, you can rename the particle by right-clicking the particle and selecting Rename Particle.

  5. Define the spheres and properties.
    1. In the Creator Tree, select PowderParticle and then select Modify Shape in the Detailed View section.
    2. Click Modify Shape and select Single Sphere from the Shape Library.
    3. In the Particles Detail table, change the Physical Radius to 0.2 mm (fine powder).
    4. Under the PowderParticle > Properties section, select the Auto Calculation checkbox.

Define the Equipment Material

The next step in setting up the model is to add the equipment material which will be used in the simulation.

To define the equipment material:
  1. Add new equipment material.
    1. Right-click Equipment Material in the Creator Tree, and then select Add Equipment Material and enter the name 'Steel' in the highlighted field.
  2. Define the equipment material properties.
    1. Select Steel in the Equipment Material section.
    2. In the Steel Properties dialog box, specify the Poisson's Ratio, Solids Density, and Shear Modulus as follows:


  3. Define the bulk material - equipment material interaction.
    1. In the Interaction dialog box, click the icon.
    2. In the Select Material dialog box, select Particle Material from the dropdown list to define the interaction between elements made of 'Powder' and elements made of 'Steel'.
    3. Specify the coefficients as follows:


      Note: The low friction coefficients of the Powder-Steel interaction correspond to the low friction material of the die and punches. Adhesion and friction are minimized in the tableting process.

Define the Geometries

The next step in setting up the model is to define the tablet press Geometry used in the model.

To define Geometries:
  1. Import the tablet press Geometry that has already been created and is ready to be imported into EDEM.
    1. Right-click Geometries in the Creator Tree and then select Import Geometry.
    2. Navigate to the files Bottom_Punch.igs, Top_Punch.igs and Factory_And_Walls.igs, and import them using the default settings.

      The letters and the Top Punch body are all imported as separate sections.

    3. Select all the five sections related to Top Punch, and select the Merge Sections checkbox.
    4. Click OK.
    5. Rename the sections of the Geometry as follows:


    6. Set the Material to Steel for all parts of the Geometry, except for the Factory Plate which should be Virtual.
  2. Specify the TopPunch kinematics.
    1. Select TopPunch in the Creator Tree Geometries section.
    2. Set the Mass of the TopPunch Geometry to 1000 g.


    3. Right-click and then select Add Motion > Add Linear Translation Kinematic.
    4. Add two linear translations to the Top Punch as follows:


    5. Add one force controller to the Top Punch as follows:


      The weight of the punch force controller will initially compress the tablet and the linear translation kinematics will eject the sample from the punch, and then finally compress to failure.

    6. Add one linear translation kinematic to the Bottom Punch as follows:


  3. Create the particle factory.
    1. Right-click factory_plate in the Creator Tree.
    2. Click Add Factory and select Dynamic Factory.
    3. In the Particle Generation dialog box, select Total Number and set the value to 6000.
    4. In the Generation Rate section, select Target Number (per second) and set the rate to 100,000 particles/s.
  4. Set the initial parameters for the factory.
    1. Set the Velocity to 'fixed' as follows:


    2. Click the icon to set the velocity in the Z-direction to -0.5 m/s.
    3. Select File > Save.

Define the Physics

The next step is to select the contact models that describe how elements behave when they come into contact with one another.

To define the Physics:
  1. Select Physics in the Creator tree and ensure that you select the Edinburgh Elasto-Plastic Adhesion model for both Particle to Particle interactions.
  2. Click the icon and specify the following input parameters:
    For Specify
    Constant pull-off force, f0 (N): Indicates the value that you can use to incorporate the permanent forces that may occur, such as Van der Waals type or electrostatic forces. The magnitude of this force will not change for the simulation duration.
    Surface Energy, (J/m2): Indicates the level of adhesion that is used in the calculation of the load-dependent adhesive force in the contact model, fmin.
    Contact Plasticity Ratio: Indicates the level of contact plasticity used in the model and this parameter defines the magnitude of the unloading/reloading stiffness k2 as a constant ratio between the initial stiffness k1 and the unloading/reloading stiffness k2. A value of zero represents elastic particle contacts, while a value of 1 leads to perfectly plastic particle contacts.
    Tangential Stiff Multiplier Indicates that the tangential stiffness used in the model can be varied. Tangential stiffness is defined as the ratio of the Virgin Loading Stiffness, k1 – a multiplier of 1 that yields a tangential stiffness equal in magnitude to the loading stiffness.


    Note: The recommended Time Step is 1.4e-6 s.

Define the Environment

The final step in setting up the tablet press model is to set the domain of the simulation.

To define the environment:
  1. Select Environment in the Creator Tree.
  2. Ensure that the Auto Update from Geometry checkbox is not selected.


  3. Increase the Max domain to 22 mm in the Z-direction.
Next Step - Run the Simulation