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EDEM v2025.0: How to Track Collision Dissipation Energies (Negative Particle-Wall Energy Loss)?
Description: I am interested in tracking the energy dissipated in collisions due to heat generation / sound / other losses in the context of a system involving multiple particles and a moving geometry mesh boundary. By tracking collisions in EDEM, I have extracted the normal/tangential/total 'Energy Loss' attributes of each collision, which are positive for particle-particle collisions, but they can be negative for particle-wall collisions. I understand that this is because 'Energy Loss' is calculated as the change in particle energy before and after a collision, and the moving mesh boundary can impart energy onto a particle. For those such particle-wall collisions, how could I calculate the energy that is lost to heat / sound / other losses (i.e., dissipation energy)?
I tried using the EDEM Energy Dissipation API posted in this community Q&A, but its outputs (as far as I could tell) lumped the information of all collisions between selected timesteps together to generate summary histograms and total system energy dissipation values. How can I retrieve the dissipation energies corresponding to each collision event that occurs in the simulation, such that the dissipation energies could be associated with the collision ID (and accordingly the coordinates, relative velocity, and involved particles of the collision)?
Product/Topic Name : EDEM v2025.0
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problem with EDEM on Linux
Hey
I am trying to make a plate fall from a height of 0.0105m with an initial velocity of 20 m/s. The time required for the plate to reach the ground is 0.5 milliseconds.
If i run the simulation in Windows and give this in the environment with this as motion defination
Gravity will be applied on the plate in -ve z.
The gravity vector will be applied to the plate as it falls down.
Now, if I do the same thing on Linux and do not give acceleration in motion definition,
It will not work. It was working only when I defined a gravity acceleration in the acceleration part of the motion
Why so?
Is this a bug in EDEM, or am I doing anything wrong here? Please let me know.
In both Windows and Linux i am using EDEM2025.
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Regarding the post-processing issues of EDEM
Hello, the particle size I simulated is relatively small, so I may notbe able to see the particles clearly on the post-processing interface. Therefore, I would like to inquire if there is a way to enlarge and display the particles so that I can better observe their state. The version I am using is EDEM2024
Thank you!
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DEM–FEA Coupled Simulation for Granular Packing
Simulating granular packing using DEM and FEA is a powerful way to analyze how granular materials interact with solid structures-especially when both the particle dynamics and the deformability of the structure are important.
Coupling DEM and FEA allows for detailed, high-fidelity simulations of granular packing in deformable domains.
Objective:
Simulate how granular materials (like powders, sand, or pellets) pack into or against deformable structures and analyze:
* Particle packing and flow behavior
* Deformation and stress in the structure
* Influence of structural deformation on particle
Prerequisites:
EDEM-OS two-way coupling supports the software version specified below or later versions
* EDEM – 2024.1
* OptiStruct– 2024.1
* SimLab – 2025.1
EDEM Simulation Setup:
https://youtu.be/i0o2hR1fIpc
OptiStruct Simulation Setup:
https://youtu.be/zSxTJdb85_I
Simulation Results:
https://youtu.be/fLKZXhwd0HI
Simulation Files:
CAD Files:
Factory and Support stl files are uploaded. Th stl files are in meter
CAD_Files.zip
Bag.fem
EDEM Files:
Bag_Filling.zip
SimLab File:
BagFilling.slb
Summary:
DEM–FEA Coupled Simulation for Granular Packing allows:
* Large geometry deformation
* Plastic strains
* Packing density
If you are looking for further information on EDEM or other Altair products we have plenty more on the Altair Community:
* EDEM Material modelling: 4 steps to accelerate your learning curve! — Altair Community
* EDEM Tutorials — Altair Community
* How to use EDEM Batch Commands — Altair Community
* Altair edemcontact_models
* Altair romAI: AI-powered Solution to Speed-up System Design and Optimization
* Discussions - Altair Community
* Altair for SimLab Learning Center
* Welcome to Altair OptiStruct
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Script for computing the temporal evolution of the Lacey mixing index for a binary mixture of particles in EDEM
Overview
This python script computes the temporal evolution of the Lacey mixing index [1] for a binary mixture of particles in EDEM from the mixture component mass fractions in a dense grid of rectilinear sampling bins as described below.
An example result from the script is shown in Figure 1. A value of zero corresponds to the perfectly segregated state and a value of one to the randomly mixed state. In addition to the graphs shown in Figure 1 the script outputs the results in a comma delimited text file.
Figure 1 a) Dense grid of rectilinear bins for the calculation of the Lacey mixing index and b) the temopral evolution of the Lacey mixing index.
[1] Gu, Z. and Chen, J. J. J. (2015) ‘A probabilistic analysis of some selected mixing indices’, Chemical Engineering Research and Design. Institution of Chemical Engineers, 93(April), pp. 293–303. doi: 10.1016/j.cherd.2014.04.014.
Pre-Requisite
EDEM 2022.3 and EDEMpy 1.2.0
Usage/Installation Instructions
The settings of the script are contained in the Lacey_settings.txt file and defined in Figure 2.
Figure 2 Inputs for the Lacey mixing index script
The python file can be executed directly from the EDEM Analyst using the Run EDEMpy script feature (File->Run EDEMpy script). The EDEM deck files, Lacey.py file and Lacey_settings.txt file should all be in the same folder. The script will find and post-process all EDEM decks in the folder that it is in and output the results in the same location.
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What equation is used to evaluate normal physical contact area
Hello
When two particles are in contact with each other and there is a bit of overlap, what equation is used to determine the value of the normal physical contact area (contact.getNormalPhysicalOverlap())
is this equal to Ac in eq33 as shown in the image?
If not, how is this variable contact.getNormalPhysicalOverlap() determined? Please give me the equation or a geometrical explanation for the same
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EDEM API - Particle Wear
Overview:
Attached to this post you will find the source code and the compiled dll/so file of an EDEM API to simulate particle wear. This model is especially useful in mining and mineral processing, where operations like grinding in ball mills involve repeated impacts that can lead to erosion of the griding media.
The model is based on equations 22 and 23 of:
Xie, Changhua, and Yongzhi Zhao. "Investigation of the ball wear in a planetary mill by DEM simulation." Powder Technology 398 (2022): 117057.
Prerequisite:
The code was developed using version 3.8 of the EDEM API. This means that it only works on EDEM 2025.0 or newer versions.
Usage/Installation Instructions:
To use the API, place the dll/so (Windows/Linux) file in the same folder as your .dem file. If you want to run the simulation using the GPU, you also have to place the .cu file in that same folder.
While in the Creator, go to the Physics section and add the model as a particle-particle and/or particle-geometry contact model. The model also has to be added in the Particle Body Force section. After loading it in the particle body force section, click on the wheel icon then set the smallest particle size allowed in the simulation. Finally, in the factory/factories set the particle/particles wear constant.
ParticleWearAPI.zip
Post-Requisite:
Release Version:
2025.0
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how to build a flexible body model
Hi Everyone,
I want to build a long flexible body model, where the particles that make up the flexible body only form bond connections with adjacent particles. The main factors affecting the fracture of the long flexible body are the contact radius, normal strength, and shear strength (the values of normal strength and shear strength are already set high enough). When I continuously increase the contact radius so that it is greater than the particle diameter, the particles will form bond connections with all the particles within the contact radius, which contradicts the previous condition of only connecting bonds with adjacent particles. The current issue is that when the contact radius is smaller than the particle diameter, the long flexible body is prone to fracture, and when the contact radius is larger than the particle diameter, extra bond connections are formed. My requirement is to establish a long flexible body that will bend without breaking, where the particles only form bond connections with adjacent particles. Do you have any good suggestions?
Best regards,
Bai
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Help with Hyperstudy and EDEM to make different tests for clay sticking inside a dumper.
Hello!
I am both using Hyperstudy 2025 and EDEM 2025.
I am working on a project where I fill up a dumper with particles and then dump it. I have had some problems to find good combinations of surface energy and other parameters for the physics models so the particles stick naturally to the dumper, so the residue in the dumper looks like real world examples. I was thinking on if I could use Hyperstudy to try different parameter combination but I have had some issues. I was thinking if it was possible to make Hyperstudy save only the last timestep so I can look at each trial and see how the particles behave with the different combinations of parameters. Is this possible? and if so how?
BR
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EDEMの粒子挙動再現およびばね構造表現に関する質問
現在，大学院の修士研究用途としてEDEMを1年間契約し，小型ドローンの着陸脚に粒状ダンパを取り付けた構造を対象に，着地時の挙動解析を行っております．
具体的には，機体をFreeCADでモデリングし，EDEMにParticle(粒子)として、インポートしたうえで，さらに粒子を内部に配置することでダンパ機構を構成しております．着陸脚の形状は円柱であり，平坦な地面に着地させる形でシミュレーションを実行していますが，離散要素法において角張った物体同士の衝突で適切な接触挙動が得られるかどうか疑問を抱いております.
また，コイルばねをEDEMでどのようにモデル化するか（あるいは代替手法があるか）についてもなにか方法がありましたらアドバイスをいただきたいです．