MotionSolve/EDEM Co-Simulation

In this tutorial, you will learn about the set-up and co-simulation of MotionSolve and EDEM through MotionView.

MotionSolve has the ability to interface with Altair EDEM, a state-of-the-art bulk material simulation tool. EDEM is based on the Discrete Element Method (DEM) that simulates and analyzes the behavior of bulk materials such as sand, granules, capsules, grass, rock masses, and so on. For more information about this method refer to https://www.altair.com/edem/ and the Discrete Element Simulation in MotionSolve topic in the MotionSolve User Guide.

This tutorial assumes minimum knowledge in both Altair’s MotionSolve/MotionView and EDEM.

Requirements
The following pre-requisites are necessary for a successful interaction between MotionSolve and EDEM:
Software Version
HyperWorks 2019.1 or later for rigid body coupling

2021 or later for flexible body coupling

2021.1 or later for PM Flex Tire coupling
EDEM 2019.1 or later for rigid body coupling

2020.3.1 or later for flexible body coupling

2021.1 or later for PM Flex Tire coupling
PM Flex Tire Latest version for PM Flex Tire coupling

PM Flex Tire is available through the Altair Partners Alliance
Note: It is recommended to install EDEM in the same location as MotionSolve (default: C:/Program Files/Altair/2024.1).

If EDEM is installed in a different location, please add ~install_location/EDEM/bin and ~install_location/EDEM/lib to the PATH environment variable for features such as geometry transfer and co-simulation to work effectively.

The steps and options described here are for the version 2024 release of HyperWorks and EDEM.
Problem Definition
The problem consists of a wheel, that can only rotate around its center. A number of particles is impinged on the wheel blades, causing it to rotate. The wheel is modeled in MotionSolve, while the particles and its interaction with the wheel is modeled in EDEM. A rigid wheel to particle interaction is set up first. The wheel is later replaced with a flexible body to show flexible body to particle interaction.
Both the wheel and the particle data are given in the table below:
Property Units Values
Particles (Bulk material)
Radius [m] 0.10
Poisson's ratio [-] 0.25
Density [kg/m3] 2500
Shear Modulus [Pa] 108
Wheel (Equipment material)
Poisson's ratio [-] 0.30
Density [kg/m3] 7860
Shear Modulus [Pa] 8.077e.1010
Before you begin, copy the file(s) used in this tutorial to your working directory.

Set Up the Motion Model

  1. Open a new session of MotionView.
  2. From the menu bar, navigate to File > Import and click on Geometry in the drop-down menu.
    Figure 1. Import Geometry


  3. Locate and select the wheel.step file from your <working directory> and click Open.
    The wheel geometry is imported into MotionView.
    Figure 2. Model in MotionView after wheel geometry import


  4. From the Ribbon, select Model and click on the Joints icon from the Entities toolbar.
    The Joints guide bar is displayed.
  5. Select the wheel and Ground Body to resolve the Body 1 and Body 2 collectors respectively, by clicking on the ellipsis next to each collector.
  6. Similarly, use the Select a Point dialog (by clicking on the ellipsis) to resolve the Point collector of Origin by choosing Bodies > wheel > Inertia Props and select wheel-Inertia Props-cg.
    Figure 3. Joints Guide Bar


    Figure 4. Select a Point Dialog to Select the CG of the Wheel Body


  7. Click Create .
  8. Using the microdialog, select Revolute Joint from the drop-down menu.
    Figure 5. Select Joint Type


  9. Navigate to the Entity Editor to ensure that the Orientation method is set to Vector and the vector is Global Z.
  10. Click to finish editing.
  11. From the Model Browser > Data Sets folder, select the Solver Gravity dataset and navigate to the Entity Editor to set the Y component to -9810 and the Z component to 0.0.
    Figure 6. Dataset - Solver Gravity


  12. Save the model as wheel.mdl.

Set Up the EDEM Model

Next, you will set up the EDEM model. EDEM modeling for this example broadly assumes the following steps that are detailed out further below:
  • Define a bulk material
  • Define a particle shape
  • Define an equipment material
  • Define the equipment geometry
  • Define a virtual geometry/particle factory
  • Define environment parameters
  • Define the simulation options
  1. Launch EDEM.
  2. In the Creator Tree, right-click on Bulk Material and select Add Bulk Material.
    Figure 7. Add Bulk Material


    A new material named 'BulkMaterial 1' is created. Leave the material properties unchanged.
  3. Click on the + sign under Interaction, on the BulkMaterial 1 Properties menu.
  4. Select BulkMaterial 1 in the pop-up window.
  5. In the Creator Tree, right-click on BulkMaterial 1 (which was just added) and select Add Shape from Library > Single Sphere.
    Figure 8. Add Single-Sphere Shape


  6. Set the Physical Radius (m) to 0.1.
    Figure 9. Particle Sphere Properties


    Optional: Due to the change in particle size, you can reset/fit the view of the particle by selecting on the View panel.

  7. Go to Properties under the New Particle 1 in the Creator Tree and select Auto Calculation.
    Particle geometry is now defined. Next, you will define the equipment material which represents the material properties for the wheel in EDEM.
  8. In the Creator Tree, right-click on Equipment Material and select Add Equipment Material.
    Figure 10. Add Equipment Material


    A new material named 'EquipMaterial 1' is created.
  9. Change the Solids density() to 7860 and Shear Modulus(G) to 8.077e10.
  10. Click on + under Interaction.
  11. In the pop-up window, click OK for BulkMaterial 1.
  12. From the toolbar on the top, click on the Start Coupling Server icon to turn on the coupling server.
    Figure 11. Turning on the Coupling Server


    This setting allows coupling with MotionView and MotionSolve.
  13. Return to MotionView and click on the EDEM Subsystem icon from the Assembly ribbon.
  14. In the panel that appears, click on to invoke the Options dialog and define the EDEM server.
    Figure 12. EDEM Guide Bar


    1. For EDEM server, choose between Local or Remote from the drop-down menu. Select Local if EDEM and MotionView/MotionSolve are on the same machine. Select Remote if EDEM resides on a different machine.
      Figure 13. Options Dialog


    2. If Remote has been selected, you will have to define the settings for the remote co-simulation, which are defined in the Bulk Material Interaction topic.
    3. Click on again to exit the Options dialog.
    4. Verify that the Graphic option is selected from the drop-down menu and click on the Graphic Advanced Selector to select the wheel graphics.
      Figure 14. Select Wheel Graphics


  15. Click on the Transfer and Create System button. If the transfer is successful, a confirmation message is displayed in the message log. Close the message log.
    A system called 'DEM 0' is added to the MotionView model. This system contains all the necessary entities for MotionSolve to simulate with EDEM.
  16. Save the model .
  17. Switch to the EDEM graphical user interface.
  18. Once the import process is complete, click on the drop-down menu within the View section on the toolbar and select the -Z view and zoom in.
    Figure 15. View Section


    The graphic screen should appear as shown below:
    Figure 16. Wheel Geometry in EDEM


    Observe the component under Geometries in the Creator tree. The wheel has the name ‘wheel’, like the body name in MotionView.

    Next, you will set up the geometry for the particle factory.
  19. In the Creator Tree, right-click on Geometries and select Add Geometry and then Polygon.
    A geometry with the name 'New Section 1' is added.
  20. Change the Type from Physical to Virtual.
    Figure 17. Polygon Geometry for the Particle Factory


  21. Select Transform under 'New Section 1' and set the following properties:
    Position Rotation
    X 1.6 1.5708
    Y 1.7 0
    Z 0 0
  22. Select Polygon under 'New Section 1' and set the following properties.
    Length
    Edge A 0.2
    Edge B 0.2
    Figure 18. Polygon properties


  23. Right-click on New Section 1 and select Add Factory > Add Dynamic Factory.
    Figure 19. Add Dynamic Factory


  24. Set the Target number (per second) equal to 5.
  25. Set bcc in Position.
    Figure 20. Adding Factory


  26. Click on the gear icon to display the Position - Lattice Parameters dialog.
    1. Under Start Point, set X and Y to 1.6 and 1.7 respectively.
    2. Leave the remaining fields set to the default values.
    Figure 21. Position - Lattice Parameters


  27. In the Creator Tree, select Environment and Under Gravity set Y to -9.81 and Z to 0.
    Figure 22. Setting Gravity


  28. Save the model as wheel.dem using the File menu or Save icon on the top toolbar.

Simulation Set Up in EDEM

  1. Switch to the Simulator.
    Figure 23. Simulator Icon on the Toolbar


  2. Click on Estimate Cell Size in the Simulator Grid menu and accept the derived cell size.
    Figure 24. Estimating Cell Size


  3. Confirm that the Coupling Server is on.
    Figure 25. Coupling Server Icon


    Tip: Hovering over the icon should show a tool tip text similar to “Listening on port 32969”.
The EDEM model is now ready to simulate with MotionSolve.

Run the Simulation

  1. In MotionView, navigate to the Model Browser, click on Default Analysis and change the following settings using the Entity Editor:
    1. From the Analysis Parameters section, change the End time to 10.
    2. From the Dynamics Settings section, set Maximum step size to 0.001.
  2. From the Ribbon, select Analyze and go to Run > Analysis settings to invoke the Run Motion Analysis dialog.
  3. Set a Results folder and the Run name.
  4. Click on the Run button to start the simulation.
    MotionSolve is invoked and the simulation should also begin on EDEM side. The simulation process should also be visible in EDEM.
    Figure 26. EDEM Graphic Screen During Simulation


  5. In EDEM, click on Auto update on the top toolbar to update the graphic visualization as the simulation progresses.
    Figure 27. Auto Update


  6. Once the simulation is complete, close the Message Log in MotionView and the MotionSolve solver window.

Post-processing

For components that are interacting in EDEM, the animation can be visualized in EDEM through the Analyst page.

  1. Click on the Analyst icon in the toolbar.
    Figure 28. Analyst Icon on the Toolbar


  2. Reset the animation with the toolbar at the bottom right.
    Figure 29. Animation Bar in EDEM


  3. Click the Animate Forwards icon .
  4. Switch back to Creator and save the EDEM model using File > Save.
  5. Translate EDEM particle results to HyperView H3D.
    1. In MotionView, from the search bar on the top right, search and select Generate H3D from EDEM results.
    2. Provide the wheel.dem file that was saved in EDEM as input and ensure that the units are correct (millimeters).
    3. Click OK.
      Figure 30. H3D Generation from EDEM Results


      On Windows, a command window is displayed, showing the progress of converting particle information into H3D. The file wheel_edem.h3d is generated.
  6. Visualize the animation in HyperView.
    1. Open a new HyperView page.
    2. Click the Open icon to load the MotionSolve H3D result in a HyperView window and click Apply.
    3. In HyperView, select the Overlay check box in the Load Model panel.
    4. Use the Open Model file browser to locate and select the wheel_edem.h3d file from the working directory.
    5. Click Apply (answer Yes to the pop-up warning message).
    6. Animate using the Start/Pause Animation button .
    Figure 31. Rigid Wheel Body Co-simulation Animation


    Note: Since geometries are represented in both MotionSolve and EDEM, the overlay would show duplicate geometries.

Flexible Body Coupling

Setting up and running a co-simulation with a flexible body follows the same steps as those performed with a rigid body in the previous step.
Note: A flexible body interaction can be set up directly. There is no need to do its rigid body interaction first.

An equivalent flexible body H3D file of the wheel is available, flex_wheel_flex_blades.h3d (previously copied to your working directory).

Figure 32. Flexible Body


The flexible body is created with the following features:
  • The rotor elements are assigned the material property steel.
  • The blade element material has a material with 10% of Modulus of elasticity and density as steel.
  • The center node is connected to the nodes on the inner surface of the rotor using rigid (RBE2 elements).
  • The center node and a node on each blade (arbitrary) has been selected as interface nodes for an adequate modal representation.
  1. From MotionView's Model Browser, select DEM system (DEM_0) and deactivate it through the right-click context menu Deactivate > Selected only.
  2. Select the body (wheel) from the Model Browser or through the modeling window.
  3. From the Body panel, select the Flex Body (CMS) check box.
  4. Browse to select the flexible body H3D file flex_wheel_flex_blades.h3d from your <working directory>.
    Observe that the same file is selected as Graphics File.
  5. Click on the Nodes & Modes... button.
  6. From the Nodes tab, find a node in the flexible body corresponding to the center joint location by clicking Find after selecting the row entry for the Joint Marker.
  7. Close the dialog.
  8. In EDEM, from the Creator context, reset the time to 0 s by clicking .
  9. Under Geometries, select the wheel geometry and delete it.
  10. Save the EDEM file as wheel_flex.dem.
  11. In MotionView, bring up the EDEM guide bar by clicking its icon from the Assembly ribbon.
  12. Change the collector to Body collector. Pick the wheel [Flex body].
  13. Click Transfer and Create System .
    The flex body should be transferred to EDEM. A new DEM system is also created in MotionView
  14. Click on the Run analysis settings button , located near the Run icon on the Analyze tab of the ribbon.
  15. Change the Run name to wheel_flex.
  16. Click Run.
  17. Once the run is complete, follow the procedures mentioned above in Post-processing Steps #4 and #5, to visualize the results.