MV-7021: 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 etc. 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
EDEM 2019.1 or later for rigid body coupling

2020.3.1 or later for flexible body 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 HyperWorks (default: C:/Program Files/Altair/202s) .

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 2022 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] 80.77.109

Set Up the Motion Model

  1. Copy the wheel.step file, located in the mv_hv_hg\mbd_modeling\motionsolve\cosimulation\edem folder, into your working directory.
  2. Open a new session of MotionView.
  3. Click on Import Geometry, , from the Standard toolbar.
  4. Locate and select the wheel.step file from your <working directory> and click Open.
    The wheel geometry is imported into MotionView.


    Figure 1. Model in MotionView after wheel geometry import
  5. Right-click on the Joint icon from the Constraint toolbar.
    The Add Joint or JointPair dialog is displayed.
  6. Select Revolute Joint from the drop-down list.
  7. Click OK.
  8. In the Joint panel that appears, select the wheel and Ground Body as Body 1 and Body 2 collectors respectively.
  9. Double click on the Point collector of Origin, navigate to the Bodies > Wheel > Inertia Props and select wheel-Inertia Props-cg.


    Figure 2. Select a Point dialog to select the CG of the wheel body
  10. Click OK.
  11. Change the Alignment Axis type to Vector and select Global Z.
  12. From the Project Browser, select the Solver Gravity dataset and set Y component to -9810. Set Z component to 0.0.


    Figure 3. Dataset - Solver Gravity
  13. Save, , the model as wheel.mdl.

Set Up the EDEM Model

Next, we 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. Open EDEM.
  2. In the Creator Tree, right click on Bulk Material and select Add Bulk Material.
    A new material named 'BulkMaterial 1' is created. Leave the material properties unchanged.
  3. Click on + under Interaction.
  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.
  6. Set the Physical Radius (m) to 0.1.


    Figure 4. Particle Sphere Library
    1. Optional: Due to the change in particle size, you can reset 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.
    The particle geometry is defined now. Next, we 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.
    A new material named 'EquipmentMaterial 1' is created.
  9. Change the Solids density() to 7860 and Shear Modulus(G) to 80.77e9.
  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 5. 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 Bulk Material Interface toolbar.


    Figure 6. EDEM Subsystem Toolbar
  14. In the panel that appears, define the EDEM server on the right side of the panel.
    1. For EDEM server, choose between Local or Remote. Select Local if EDEM and MotionView/MotionSolve are on the same machine. Select Remote if EDEM resides on a different machine.
    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 the Graphics collector and select the wheel graphics.
  15. Click on Transfer and Create System. 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 7. View Section
    The graphic screen should appear as shown below:


    Figure 8. 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, 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 9. 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 10. Polygon properties
  23. Right-click on New Section 1 and select Add Factory.
  24. Set the Target number (per second) equal to 5.
  25. Set bcc in Position.


    Figure 11. 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 12. Position - Lattice Parameters
  27. In the Creator Tree, select Environment and set the Gravity – Y to -9.81.


    Figure 13. 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 14. Simulator icon on the toolbar
  2. Click on Estimate Cell Size and accept the derived cell size.


    Figure 15. Estimating cell size
  3. Confirm that the Coupling Server is on.
    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. Go to the Run panel .
  2. Click on Simulation Settings and go to the Transient tab.
    1. Set Maximum step size to 0.001.
    2. Close the dialog.
  3. Change the End time to 10.
  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 16. 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 17. 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 18. Analyst icon on the toolbar
  2. Reset the animation with the toolbar at the bottom.


    Figure 19. Animation bar in EDEM
  3. Click the Animate Forwards icon .
  4. Translate EDEM particle results to HyperView H3D.
    1. In MotionView, from the EDEM menu, select Generate H3D from EDEM results.
    2. Provide the wheel.dem file that was saved in EDEM as input.
    3. Click OK.
      On Windows, a command window is displayed, showing the progress of converting particle information into H3D. The file wheel_edem.h3d is generated.
  5. Visualize the animation in HyperView.
    1. From the MotionView Run panel, click Animate to load the MotionSolve H3D result in a HyperView window.
    2. In HyperView, activate the Overlay check box in the Load Model panel.
    3. Use the Open Model file browser to locate and select the wheel_edem.h3d file from the working directory.
    4. Click Apply (answer Yes to the pop-up warning message).
    5. Animate using the Start/Pause Animation button .

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. It's not necessary to perform its rigid body interaction first.

An equivalent flexible body H3D file of the wheel is available.

  1. Copy the file flex_wheel_flex_blades.h3d, located in the mv_hv_hg\mbd_modeling\motionsolve\cosimulation\edem folder to your working directory
  2. 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.


    Figure 20.
  3. Return to the MotionView window.
  4. Select the DEM system (DEM_0), deactivate it through the right-click context menu Deactivate > Selected only.
  5. Select the body (wheel) from the Model browser or through the graphics area.
  6. From the Body panel, active Flex Body (CMS).
  7. Select the flexible body H3D file flex_wheel_flex_blades.h3d as the Graphical source.
  8. If a confirmation dialog prompts you to confirm the use of the same file as the Functional source, click Yes.
  9. Click Nodes….
  10. Find a node in the flexible body corresponding to the center joint location by clicking either Find All or Find on the row entry for the Joint Marker.
  11. Close the dialog.
  12. In the EDEM GUI, click Creator to return to the creator context.
  13. Reset the time to 0 s.
  14. Under Geometries, select the wheel geometry and delete it.
  15. Save the EDEM file as wheel_flex.dem.
  16. In MotionView, load the EDEM System panel.
  17. Change the collector to the Body collector. Pick the wheel [Flex body].
  18. Click Transfer and Create System.
    The flex body should be transferred to EDEM. A new DEM system is also created in MotionView
  19. Go to the Run panel. Change the XML filename to wheel_flex.xml.
  20. Click Run.
  21. Once the run is complete, follow the procedures mentioned in Post-processing, steps 4 and 5, to visualize the results