This article explains two main approaches for defining flexible tire motion in Altair EDEM using PM FlexTire™, and provides step-by-step examples for coupling EDEM with MotionSolve.
Options for Defining Flexible Tire Motion
- EDEM’s Built-in Kinematics, Force, and Torque Controllers
- Pros: Easiest to set up and fastest to solve.
- Cons: Limited functionality compared to coupled simulations.
- Coupled Simulation with Altair MotionSolve
- Pros: Recommended for full vehicle simulations with independent suspension, undulating terrain, or varying travel directions.
- Best Used For:
- Full vehicle dynamics
- Independent suspension modeling
- Terrain following with slope changes
- Maneuvers requiring direction changes
Requirements
- Altair EDEM 2025 or later
- Altair MotionView 2025 or later
- PM FlexTire™ license (enabled via the Altair Partner Alliance)
Example 1 – Simple Single Tire EDEM–MotionSolve Coupling
This example demonstrates coupling EDEM and MotionSolve for a single tire using PM FlexTire™. The example files can be downloaded from the PM FlexTire™ Example section of the Altair Marketplace.
Demonstration:
A single flexible tire is rolled over a particle bed in EDEM, with tire motion driven by MotionSolve as shown in the video below.
Step-by-Step Setup
Step 1 – Open Required Files
- In EDEM: Open
input.dem. - In MotionView: Open
Single_tire_start.mdl.
Step 2 – Access Tire Setup in MotionView
- Entity Browser → Vehicle Tool → Components → Tire
- Select hub and centerline locations via the GUI.
Step 3 – Assign Markers
- Tire Marker: Select from the system marker list.
- Road Marker: Select from the system marker list.
Step 4 – Assign Tire Property File
- In the Tire Entity Editor, select the
.fxt file (MTR325x125R165.fxt) from the example files. - Set file type filter to All Files to see
.fxt.
Step 5 – Assign Road Property File
- Select
2D_Cleat_road.rdf from the example files.
Step 6 – Generate FlexTire Files
- Select the tire CAD file (
MTR37x125R165.stp). - Verify output directory.
- Select PM-FlexTire converter (
STP_to_OBJ). - Set Fidelity to 8.
- Adjust rim/belt diameter as needed.
- Click OK to generate
.OBJ, .BDF, and .OFF files.
Step 7 – Enable Coupling in EDEM
- In Creator, enable Coupling Server.
Step 8 – Connect EDEM and MotionView
- MotionView → Assembly → EDEM → Set Type to Tires → Select generated tire.
- Save both EDEM and MotionView files.
Step 9 – Set Hierarchy in EDEM
- Make the rim a child of the tire.
Step 10 – Verify Physical Parameters
- Match tire pressure, inflation time, and tire mass to
.fxt file.
Step 11 – EDEM Simulation Settings
- Enable GPU solver if available.
Step 12 – MotionView Coupling Settings
- Set communication interval (1–100 EDEM timesteps per MotionSolve communication).
Step 13 – Run Coupled Simulation
- In MotionView → Analyze → Enable Run Offline with solver format set to XML.
- Start simulation with EDEM Coupling Server enabled.
Example 2 – Pickup Truck EDEM–MotionSolve Coupling
This example covers a full vehicle simulation using PM FlexTire™. Steps are similar to the single tire example but applied to a multi-tire vehicle model:
- Load the prepared EDEM simulation.
- Open the MotionSolve
.mdl in MotionView. - Assign hub, centerline, Tire Marker, and Road Marker.
- Link
.fxt file in Tire Entity Editor. - Configure coupling parameters in EDEM.
- Run simulation and review real-time tire–terrain interaction.
How to Video
The Step-by-step video can be access here: Altair How-to-Video
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