10 unique features and capabilities of EDEM you need to know about!

Post originally published on October 31, 2019
Revised: April 2021

At Altair we work closely with our customers to ensure our technology meets their needs. Quality and innovation have always been at the core of our work and this is why EDEM is the most advanced and validated Discrete Element Method (DEM) software on the market. We are constantly adding new functionality to further improve the usability, speed and capability that EDEM delivers.

In this post we are highlighting 10 key capabilities and resources we have that really make a difference to our users.

Have a look and get the most out of EDEM!

MATERIAL MODELS LIBRARIES

When performing DEM simulations a key aspect is to get suitable material inputs for accurate representation of granular materials. The whole process of figuring out the right input values can be daunting – particularly for those who are new to using DEM – so, to make life easy, we have developed unrivalled resources to help users introduce the right virtual material models quickly and easily into their simulations.

• Generic EDEM Material Model (GEMM) Database
  The GEMM database contains over 60,000 pre-calibrated material models representing a wide variety of rocks and ores. Users only need to answer 3 questions about their real-life material to obtain a suitable material model: the size of their application, the bulk density of the material and the angle of repose. Based on this information, the GEMM Database immediately provides them with an EDEM Material Model that contains all the required physics and associated parameter values needed to match the behavior of their real material. The GEMM Database is built-into the EDEM Creator for easy access.

In addition, for more complex materials such as soft cohesive soils and fine powders, we have developed a set of example materials models making use of advanced physics to best represent this type of advanced behavior:

• The Soils Starter Pack includes 8 models of soils including different ranges of compressibility and stickiness. These models make use of advanced physics models inbuilt in EDEM to model a range of soils from gravels to soft compressible soils. Read more here.

• The Powders Starter Pack is designed to be a useful starting point for anyone needing to simulate the complex nature of powders. It consists of a selection of 9 example material models focusing on small particle sizes and representing a range of materials with different flow properties and compressibility. Read more here.

The example models from the Starter Packs can be accessed directly from within EDEM and are ready to be used in a simulation. This is part of our objective to make DEM simulation more accessible to engineers and to give them a starting point to using different physics models. 

BED GENERATION TOOL

Many applications notably in the construction, mining, off-road and agriculture industries involve equipment and machinery interacting with large beds of material. With the Bed Generation Tool (also known as Material Block) users are able to create such beds of material quickly and easily without needing to wait for material to be injected into a simulation using time-dependent inlets. Instead, EDEM offers a smart and efficient approach where small blocks of material are used to build massive beds of material instantly. The blocks can be re-used, stored and easily transferred between multiple users and simulations which saves both setup time and simulation time.

Screenshot of the EDEM Creator

A large, 200-meter-long bed of off-road material to simulate a vehicle “double lane change” maneuver. The bed was created rapidly using EDEM Bed Generation tools and, with use of the Dynamic Domain and GPU, the 200m travel of the vehicle was simulated in 2 hours.

In addition, the ‘volume packing’ functionality introduced in EDEM 2021 enables users to auto-generate tightly packed beds quickly and according to specific criteria such as porosity or a given level of compaction. This works for any closed volume geometry and can be applied to arbitrary shapes but also uniform shapes such as cylindrical hoppers. It is a faster method than the traditional way of introducing large amounts of material and, once generated, these beds are saved as material blocks that can be easily introduced at any time during a simulation or re-used in other simulations.

The volume packing capability makes it possible to generate packed beds within minutes.

DYNAMIC DOMAIN

As mentioned above, some applications for instance agricultural or off-road require simulating long beds of material, which can impact simulation times. This is where the Dynamic Domain comes into play. The Dynamic Domain is unique to EDEM and is one of the most advanced DEM processing tools available. Unlike other DEM tools that require you to solve all particle contacts at all times during a simulation, EDEM Dynamic Domain technology allows users to focus all their processing power (be it GPU or CPU) on where the action is happening by creating an active region around equipment parts. This means you can create huge beds and volumes of material without increasing computational cost.

The Dynamic Domain makes it possible to create an active domain to only solve contacts in necessary areas.

EDEM GPU AND MULTI-GPU SOLVERS

One common request from DEM users is to be able to simulate big simulations involving millions of particles in a manageable time. To support this, EDEM makes it possible for users to run their simulations using their computer’s Graphical Processing Unit (GPU), which means they can run simulations faster and also can run larger simulations than what was possible on CPU alone. The GPU and multi-GPU solvers are fully double-precision to guarantee accuracy and have been developed on OpenCL thus providing flexibility for users to use either AMD or NVIDIA cards.

Some of our benchmarks have shown speed-up of up to 12 times when using GPU as opposed to CPU only and we have users who have reported simulations using GPU being almost 20 times faster!

The GPU solver is compatible with API models and the EDEM coupling interface enabling all users to benefit from a speed-up regardless of how complex their simulation is. For more information about EDEM GPU read this post.

MULTI-SPHERE AND POLYHEDRAL PARTICLE SHAPE SOLVERS

Users can choose between two solvers, depending on their specific application. The multi-sphere approach remains the preferred option for most cases as it offers the right balance of computational efficiency and accuracy. A polyhedral particle solver is also available for cases where a more precise shape is desirable – for example, high-aspect ratio particles (such as flat plates), or very uniformed shape particles such as cubes or cylinders.

Read more about the polyhedral solver and when to use it in this article.

Examples of the EDEM polyhedral solver. [Clockwise from top left] Cubic elements in a mixing drum; flat plates discharging into a container; high-aspect ratio particles in a screw auger.

EDEM’S APPLICATION PROGRAMMING INTERFACE (API)

Do you need to simulate advanced and complex material behaviors? Whether it is liquid effects, agglomeration, breakage, flexible fibers, magnetic particles, it is all possible using EDEM’s highly versatile API which enables users to write their own custom physics. API models can be run directly on the GPU solver which means you can benefit from the performance boost that the GPU provides. The EDEM API is also compatible with the polyhedral particle solver. A range of models are available from the Altair Knowledge Base.

Examples of advanced material behavior that can be done using EDEM’s API

TAVARES BREAKAGE MODEL IN EDEM

Breakage is a key application for a lot of users especially in the mining and mineral processing industries. We have been working closely with experts in the field of comminution and particle mechanics, including Professor Marcelo Tavares of Universidade Federal do Rio de Janeiro (UFRJ) and Professor Jin Ooi of the University of Edinburgh, to deliver a breakage model based on well-established and validated physics following the latest advances in research. The resulting EDEM breakage model is able to simulate all breakage mechanisms of brittle materials including both weakening and fragmentation. It can simulate any type of breaking mechanism: compression, shearing, weakening etc. The model uses spheres as this is the only shape that is consistent with the physics behind it as well as the fastest.

For more information read this article.

Breakage in SAG mill and in jaw crusher

EDEMPY FOR POST-PROCESSING SIMULATION DATA

The drive for large simulations also means more data to process. This has led us to develop ‘EDEMpy’ – a Python library for post-processing and analysis of EDEM simulation data which takes advantage of the EDEM .h5 file structure. Using the library, it is easy to extract specific data from a simulation deck and process that data in a customizable and reusable way. Users can, for example, extract force acting on a specific geometry over time and compare results back to back between multiple simulation decks, track particles residence time over the course of a simulation, visualize networks of contacts and bonds in a new flexible way, visualize DEM data as a continuum or use EDEM data to calculate post processing properties for their simulations such as segregation index or tortuosity.

For more information about EDEMpy read this post.

EDEMpy can be used to easily calculate the segregation index for a mixing application

DEFORMABLE GEOMETRIES

The ability to simulate how a geometry is being deformed as a result of a bulk material acting on it is something that is of key interest for numerous applications and which has been under development at EDEM.

The EDEM solver engine facilitates continuous modification of a geometry structure during simulation. This means geometry sections can change shape and deform with input via the EDEM Coupling Interface. This enables users to directly couple EDEM to flexible body simulations to cover a wide range of applications such as belts, sheet panels, elastic membranes and many more. Future developments will make it easier and easier for users to be able to change geometries according to particle actions.

A flexible geometry coupling with multi-body dynamics software is also available that allows for prediction of deformation and stress within individual parts. This capability allows for even greater realism and insight into real-world systems.

Example of geometry deformation for a mill (Before and after)

DEM-MotionSolve simulation of an excavator with the bucket as a Flexible Body

EXTENSIVE CAE INTEGRATION

We know that you will be using a number of different CAE tools and it is critical that these tools work well together. That is why EDEM is the most well connected, CAE-friendly DEM code available.

A large number of solutions are available including couplings between EDEM and OptiStruct, MotionSolve and AcuSolve, as well as with 3rd party Finite Element Analysis (FEA), Multi-body Dynamics (MBD) and Computational Fluid Dynamics (CFD) tools.

Our EDEM Coupling Interface also enables users to write their own couplings with any other tool of their choice. Coupled simulations can be run on GPU and we’ve seen some great examples of speed-up.

Bringing everything together….

To end with, let’s have a look at the example below of an all-terrain vehicle, making use of 5 capabilities highlighted in that post.

In this example, a soil-like material was easily introduced using the GEMM Database. Using the bed generation tool, a long bed of that material was quickly generated. EDEM was coupled with a MBD software to realistically simulate the tire-ground interaction. The simulation was run on GPU using the dynamic domain. It resulted in a fully-coupled 1,000,000 particle simulation which was calculated in just 3 hours, many times faster than would have normally been possible.

LEARN MORE

To learn more about these capabilities and how to use them in EDEM check our Introduction to EDEM eLearning course.