Vibrating Roller Compactor Performance Using MotionSolve and EDEM Co-simulation
Altair EmployeeOverview
Vibrating Roller Compactor Performance Using MotionSolve and EDEM Co-simulation
CHALLENGE
Assessing Vibrating Roller Compactor components and their performance within a co-simulation framework.
Introduction
A standalone model built using a specific simulation tool holds good for understanding the basic performance of a system. However, adopting a co-simulation or a multi-physics methodology provides more insight into the influence of different parameters and variables affecting the performance of the specified problem domain. The vibrating roller compactor is a staple of construction equipment that is commonly seen in construction sites around the world. Its main importance is to compact soils, gravel, asphalt, and other materials to create a more stable base for building. The main contributor for this machine is the eccentric shaft located inside the drum. By creating an imbalance in the drum, the drum vibrates which helps compact the material even further. Common practice is to first pass over the surface without the eccentric on to flatten the material by the weight of the vehicle alone. A second pass is made where the compactor reverses’ over the material. A third pass is made with the eccentric turned on to increase the stability of the area.
Altair’s Motionsolve or other MBD tools like ADAMS, would provide insights into the dynamics and kinematics of the whole system. By incorporating EDEM, a discrete element method solver, interaction between the compactor and material particles can be simulated. This provides the ability to simulate multiple scenarios with different materials to analyze the forces on the compactor’s components. In addition, this will provide great insight on the compaction of the particles.
Understanding the Model Definition in MotionView
The MBD model of the vibrating roller compactor is built to test the eccentric shaft after the compactor does its initial pass over the material. In the model browser we can observe the setup of the eccentric motor located in the “Front_Drum_Assembly”.
A dataset is defined for the eccentric motor. The inputs correspond to a step-dwell-step function:
Speed - maximum speed to obtain.
Start Time – when in simulation to start the eccentric.
Step-On - duration to reach the max speed.
Dwell Time - duration the max speed is kept.
Step -Off - duration for the eccentric motor to turn off.
A motor defined in the “Rear_Assembly” is used to set the speed of the rear wheels and the duration for all three phases where the compactor goes over the material without the eccentric enabled, reverse over the material and go over the material again with the eccentric turned on.
The front drum, tierod, and rear wheels geometries were sent over to EDEM to retrieve the corresponding forces from the particle interaction.
Understanding the Model Definition in EDEM:
The EDEM model includes 180,000 particles with a 58 mm particle diameter. Particle properties come from the GEMM library, a source of validated bulk material properties. Particle-particle interactions are modeled using the Edinburgh Elasto-Plastic Adhesion contact model. While the particle-geometry interactions are modeled using the Hertz-Mindlin with JKR contact model, which accurately and efficiently compute forces.
Pre-Requisite
SOFTWARE REQUIREMENTS:
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- Operating System: Windows
- MotionView (2024 or newer)
- MotionSolve (2024 or newer)
- EDEM (2024 or newer)
- Workable knowledge of MotionView and EDEM preferred.
Model Files:
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- Model_Files.zip
Usage/Installation Instructions
Model Setup and Simulation Steps:
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- Open a new MotionView session.
- Load in the “Compactor_Archive.mdl”
- Verify the ground graphic is deactivated, and a DEM system is present.
- Open a new EDEM session.
- Load in CompressibleSoftStickyMaterial_Export.dem
- Turn on the coupled server
- In MotionView, run the analysis
- Once the run is complete load in the particle and MotionSolve results into HyperView to observe the animation
- Particle data can be queued from EDEM
- Results regarding the components of the vibrating rolling compactor can be viewed in HyperGraph.
Post-Requisite
Results
Examining the EDEM results, the compactor effectively flattens the particles during both its initial and reverse passes. The eccentric pass further compacts the particles and enhances the porosity of the treated area, resulting in a stable foundation for construction.
Reviewing the MotionSolve results, an initial spike in drum forces is observed, which can be attributed to the compactor settling onto the material and can be disregarded. When the eccentric mechanism is activated, additional noise is noted in the drum forces, indicating that the eccentric is counteracting the drum’s motion and generating increased vibration. Further analysis could explore how different materials affect the compactor system's performance.
Conclusion
The co-simulation of the vibrating roller compactor using MotionSolve and EDEM has provided valuable insights into the machine's performance and component interactions. The integration of multi-physics simulations allowed for a comprehensive analysis of how the compactor interacts with material particles and how its internal mechanisms, particularly the eccentric shaft, affect overall performance.