EDEM Simulation
By Corinne Bossy

Do you design heavy equipment such as truck bodies, dozers and excavators?

If so then I’m sure you are very familiar with tools such as Finite Element Analysis (FEA) and Multi-body Dynamics (MBD) to help design your equipment. When using such tools one challenge is to determine the loads acting on equipment.  Hand-calculations, assumptions, or physical testing are common methods but they have limitations especially when it comes to equipment intended to handle bulk materials such as rocks, ores, soils or sand. You could be dealing with large quarry rocks that are generating high force impacts; or perhaps a fine but highly abrasive material such as sand; or a cohesive soil that might stick to equipment. This sort of variability means it is very difficult to predict how materials will behave with a piece of equipment and impact on its performance.



This is where bulk material simulation and EDEM software technology come into play. EDEM simulates the behavior of bulk materials and provides accurate loads for a range of materials types including rocks, gravels, ores and more cohesive materials like clays and soils.



While this technology has traditionally mainly been used by a small pool of experts in the field, latest developments mean it is now easily available to a wider number of engineers.

The development of key partnerships between EDEM and leading CAE companies has led to the release of specialized products known as ‘EDEM for CAE’ which connect to widely used FEA and MBD platforms. With these tools, design engineers can add realistic bulk material loads directly and easily in their structural analysis and their system dynamics analysis. This means they no longer have to rely on hand calculations and assumptions to predict the effect of materials on their equipment, which in turn leads to improved designed accuracy and performance, not to forget reduction in the frequency and cost of physical prototyping.

At present the EDEM for CAE range includes EDEM for ANSYS, EDEM for Adams and EDEM for LMS Virtual.Lab Motion. The tools have a very easy-to-use interface and do not require any expertise in bulk material simulation to operate. All the analysis is performed in the host software in an environment familiar to the user.



To find out more about the EDEM for CAE tools and how they can benefit your design processes check our webinar series. Our EDEM engineers will take you through applications examples and show you the workflow of each tool.

WEBINAR SERIES

In addition, if you’re ready to jump-in and learn how to use each tool, check our free eLearning courses. You’ll even get a free trial once you complete a course.

Note: if you are interested in bulk material simulation but use another FEA or MBD tool, we do offer coupling solutions with other providers. Just get in touch to discuss your needs.

Source: EDEM Simulation Blog

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EDEM Simulation
By Carles Bosch Padros on 12 Oct 2017

Bulk materials are complex in nature and simulating their flow can be challenging. Choosing the right contact model in your simulation is critical to capture realistic behavior.

Here I would like to introduce a contact model that has been developed by EDEM academic users at the University of Edinburgh to simulate complex cohesive materials such as fine dry powders, organic materials, soil and ore fines.

Such materials exhibit a behavior which can be characterized by elasto-plastic deformation under loading and accompanied by an increase in cohesion. The complexity of these materials means they are beyond the scope of standard contact models.


THE EDINBURGH ELASTO-PLASTIC ADHESION (EEPA) MODEL

The Edinburgh Elasto-Plastic Adhesion (EEPA) model has been developed by a team of researchers of the University of Edinburgh including Dr. J. P. Morrissey, Dr. S. Thakur, Prof. J.Y. Ooi, Dr. J.Sun and Prof J-F. Chen. This model was initially developed using EDEM’s Application Programming Interface (API) and as part of EDEM 2018 it is now built-in and available to use as a standard contact model in EDEM. The EEPA offers a solution for cohesive granular solids whose behavior changes depending on the stresses experienced by the material beforehand. In other words, this contact model accounts for the stress history of the granular material, which helps defining its cohesive behavior.

In a real situation, we would have a bulk material or powder being compressed together. During this procedure, some of the deformations would be elastic and some others plastic. Once the compression has stopped and the material has finished the unloading (force=0), an overlap will remain. The EEPA contact model is non-linear and able to capture both the elasto-plastic deformation and the contact-area dependent cohesion.

I will not go into details about the model itself here but full documentation is available to our customers in the EDEM Documentation. Instead let me show you a couple of simulation examples to illustrate the applications of this model.


APPLICATION EXAMPLE #1: DUMP TRUCK UNLOADING MATERIAL


Dump trucks have to be as efficient as possible in order to reduce the time and travels needed for transportation. Using the elasto-plastic contact model in EDEM in this case would give us insight into:

  • Regions where the material is likely to stick
  • Quantity of material that will stick
  • The effect of geometry on material adhesion

The difference in the amount of material stuck in the dump after the unloading is due to its initial filling level. The initial compression of the material affects the level of cohesion showed by it. In this case, the truck on the left was filled with a heavier load than the right truck, which compressed the material more and, hence, offered a higher level of stickiness, as seen at the end of the video.


APPLICATION EXAMPLE #2: SOIL-TYRE INTERACTION: TRACTOR


When looking at machine-material interaction EDEM can provide insights into:

  • Regions where the material is likely to stick
  • More realistic traction forces
  • More realistic pressure distribution


APPLICATION EXAMPLE #3: PHARMACEUTICAL TABLETTING


In this example EDEM gives insights into:

  • Initial bulk density and porosity in the mould
  • Change of volume and bulk density during compaction
  • Forces during compaction
  • Tablet stability after compaction


APPLICATION EXAMPLE #4: STORAGE AND DISCHARGE: SILOS




Using the EEPA model in EDEM provides information on:

  • Cohesive flow discharge
  • Arching phenomenon in silos
  • Material state during storage (Bulk Density, Porosity etc.)
  • Silo wall pressure distribution during storage and discharge

These are just some examples of applications of the Edinburgh Elasto-Plastic Adhesion model. This versatile model can represent complex cohesive materials and phenomena such as fine agglomeration, attrition and flow.

If you want to find out more about this model or want to chat about other advanced applications, get in touch!

Source: EDEM Simulation Blog
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EDEM Simulation
By Corinne Bossy on 09 Aug 2017

Back in 2013 we launched the DEM Literature Database. The concept? Creating a searchable online database containing abstracts and references of all the published literature in the field of Discrete Element Modeling.

This resource has quickly become very popular and is currently used by over 500 individuals every month. Some browse the database to keep up to date with the latest publications, others to find out about key applications or potential research that has been carried out in a specific area.

As we have recently added the 5,500th abstract, we took this opportunity to look at some key data and see how the number of publications has grown over the years, what the most popular topics are, as well as the top authors and journals based on the number of papers published.

 

Some of the ‘hot’ research topics we see when looking at keywords provided include mixing, segregation, comminution, fracture and a huge portion involve DEM coupled with Computational Fluid Dynamics (CFD) to investigate particle-fluid systems such as fluidized beds.

Looking at the number of publications over the years we can see that DEM has been a growing research field and this is good news when it comes to validating the application of this technology and accelerating its adoption and usage by industry.

At EDEM we are proud to support academic research with our EDEM Academic Partner Program. We are lucky to have a strong community of thousands of academic users worldwide who drive the development of EDEM and foster innovation. If you want to find out more about EDEM for Academia visit this page.

Of course maintaining the database is not a small job, therefore we count on you to let us know what is missing and to send us details of papers you publish at dempaper@edemsimulation.com

The DEM Literature database is open to all, start browsing through abstracts here.

Source: EDEM Simulation Blog
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