Combined finite-discrete element methods for multi-body dynamics and fracture mechanics

As the corresponding organiser of a joint 14th World Congress in Computational Mechanics and ECCOMAS Congress 2021 mini symposium, I invite you to join the virtual congress that will be held from January 11 to 15, 2021. This series of talks will cover the latest research developments and new methods in multi-body and fracture simulations with finite element methods (FEM) and discrete element methods (DEM), with a particular emphasis on combined finite-discrete element methods (FDEM), and with output from researchers from a variety of applied and multidisciplinary fields. It will be a chance to hear on the features of computational technologies developed by researchers around the world, and the latest research developments for multi-body systems and fracture simulations with FEM, DEM and FDEM. It will be a platform to bring together academics and industry specialists who are using and developing FDEM codes. It will also provide a great opportunity for people who have just started working with combined finite-discrete element methods to discuss with world experts in this field. The research areas that will be discussed include (but are not limited to):

• Numerical algorithms and optimisation techniques for combined finite-discrete element methods;

• Validation studies of multi-body and fracture simulations with experimental results;

• Coupling methods and applications for multi-physics (e.g. fluid and thermal) structural problems;

• Chemical and pharmaceutical applications (powder compaction, tableting, reactors, etc.);

• Civil and mechanical applications (track ballast, tunnelling, mechanical components, etc.);

• Rock mechanics, petroleum and mining applications (underground excavations, hydraulic fracturing, CO2 sequestration, etc.).

Some of the discussion will focus on open problems and on the challenging aspects of FDEM in fracture
simulations, such as the joint-element induced artificial compliance, element size constraints due to the
discretisation of the process zone, dynamic effects induced by the application of boundary conditions
(e.g. in-situ stresses), and so on. Algorithms for the combined finite-discrete element method (FDEM)
started to be proposed from the 90s. Extensive developments and applications of the FDEM method
have been carried out after the release of the open source Y-code in [1], and different versions have been
released, including the code developed from the collaboration between Queen Mary University and Los Alamos National Laboratory [2], the Y-Geo and Y-GUI software that have been developed by the Geomechanics Group at Toronto University [3], and VGeST (Virtual Geoscience Simulation Tools) released by the Applied Modelling and Computation Group (AMCG) at Imperial College London. Recently the AMCG has upgraded and renamed VGeST as ’Solidity’. A commercial FDEM code developed by Geomechanica (, has also been released in Canada, although its application has been limited to modelling geomaterials. While the first Y-code employed finite strain elasticity coupled with a smeared crack model to capture deformation, rotation, contact interaction and fragmentation, the AMCG has greatly improved the code, implementing a range of constitutive models [4, 5], thermal coupling [6], parallelisation and a faster contact detection algorithm [7] with applications in different fields [8, 9].

The deadline to submit your abstract to this mini symposium is October 25, 2020.
The registration fee is € 250 (€ 150 if you are a student). 

When you submit your abstract, after filling the Title and Author(s) sections, please select the following from the MS list:
1200 – Modeling and Analysis of Real World and Industry Applications / MS454 – Combined finite-discrete element methods for multi-body dynamics and fracture mechanics

You can find more info and the instructions for the authors on the conference websitePlease, do let me know if you need any help with your submission.

More information about the virtual congress

In a nutshell
WCCM-ECCOMAS Congress will take place in digital version from January 11 to 15, 2021 and all those who already have an accepted paper will be able to propose a recording of their talk via a platform provided and to participate in virtual moments of exchange. 

A digital event
The tragedy of the covid-19 pandemic has made impossible to organis
e the joint 14th World Congress in Computational Mechanics and ECCOMAS Congress in Paris in July 2020. The enthusiastic response of all the community with more than 400 mini-symposia (MS) and more than 5000 papers accepted, along with an exceptional implication of the young community, has motivated the organisers to do whatever was possible in order not to lose the work and involvement of so many scientists. 

We first tried to postpone the congress, in its classical form, to another date. Despite our effort, this has led us to a dead end. This is why finally we have worked hard to propose the community the best possible virtual event with the best possible digitalised format and technical solutions. Even though we have seen, since the beginning of the covid-19 crisis, many similar events, a virtual WCCM-ECCOMAS has one particular feature: its size. Designing such an event has taken a tremendous effort and this is why we have remained silent. We apologise for that.

We are convinced that this new format, even with some drawbacks, has many advantages, in particular for young scientists but also for the others. For instance, it will become possible to follow all the presentations, browsing easily all the MS, surfing by keywords from one room to another and selecting only the talks that you want. The different talks will be available over a longer period than the classical one-week format. We paid special attention to maintain interaction between the participants to that purpose, direct exchanges with other participants, either by voice or by chat will be possible.

We hope you will embrace our proposal as a mean to create an enthusiastic and successful scientific event for our community. 

Is the organisation going to start from scratch?
In order not to lose all the hard work of everyone, we will start again from the organisation that had been set up for the original event. In particular, we propose to keep all the MS of the accepted papers. All the MS organisers and contributors will soon receive a message asking them if they wish to continue the process and keep their MS and submission as it is. 

How to deal with the different time-zones?
Participants will spread out across the world, which makes the task a little bit tricky. All the talks (20-minute regular talks, semi-plenaries, plenaries) will be pre-recorded at home using online facilities provided by the congress. All the MS will be available at the same time, all along the congress week. It will allow participants to “attend” all the presentations whenever they want. For each MS, a live Q&A session will be organised, as well as chat discussions, where attendees and authors can meet themselves. Semi-plenaries, plenaries and special events (opening, closing ceremonies…) will be released at given times of the week, following a given calendar compatible with a maximum of time-zones (around noon, Paris time-zone). However, they will remain available for the rest of the congress.

How to record my presentation at home?
All the facilities will be provided by the conference through the web. A couple of weeks before the congress, participants will receive an email with all the necessary explanations from our provider for the recording. Participants will record themselves with the provided tool (webcam + presentation with their usual software) as many times as they wish. When they are happy with their performance, they upload the files to our provider‘s cloud and our provider takes care of all post-processing (synchronis
ation of video and slides, possible reprocessing of sound and images). The final result will be directly available in the corresponding MS virtual room.

What will the new registration fee be?
The fee will be 250€ for delegates and 150€ for students who will present a contribution (with a 10% reduction to IACM  and ECCOMAS members). A special fee of 75€ will be available for non-presenting delegates. Further information will be soon available on the 
conference website.


[1] A Munjiza. The Combined Finite-Discrete Element Method. Wiley, 2004.
[2] E Rougier, EE Knight, ST Broome, AJ Sussman, and A Munjiza. Validation of a three-dimensional
Finite-Discrete Element Method using experimental results of the Split Hopkinson Pressure Bar test.
International Journal of Rock Mechanics and Mining Sciences, 70:101–108, 9 2014.
[3] O. K. Mahabadi, A. Lisjak, A. Munjiza, and G. Grasselli. Y-Geo: New Combined Finite-Discrete
Element Numerical Code for Geomechanical Applications. International Journal of Geomechanics,
12(6):676–688, 12 2012.
[4] A Farsi, A Bedi, J P Latham, and K Bowers. Simulation of fracture propagation in fibre-reinforced
concrete using FDEM: an application to tunnel linings. Computational Particle Mechanics, 12 2019.
[5] N Karantzoulis, J Xiang, B Izzuddin, and J P Latham. Numerical implementation of plasticity
material models in the combined finite-discrete element method and verification tests. pages 319–
323, 2013.
[6] C Joulin, J Xiang, JP Latham, and C Pain. A New Finite Discrete Element Approach for Heat
Transfer in Complex Shaped Multi Bodied Contact Problems. In Xikui Li, Yuntian Feng, and Graham Mustoe, editors, Proceedings of the 7th International Conference on Discrete Element Methods,
pages 311–327. Springer Singapore, Singapore, 2017.
[7] J Xiang, JP Latham, and A Farsi. Algorithms and Capabilities of Solidity to Simulate Interactions
and Packing of Complex Shapes. In Xikui Li, Yuntian Feng, and Graham Mustoe, editors, Proceedings of the 7th International Conference on Discrete Element Methods, pages 139–149. Springer
Singapore, Singapore, 2017.
[8] Ado Farsi, J. Xiang, J. P. Latham, M. Carlsson, E. H. Stitt, and M. Marigo. Strength and fragmentation behaviour of complex-shaped catalyst pellets: Anumerical and experimental study. Chemical
Engineering Science, 213:115409, 2020.
[9] John Paul Latham, J. Xiang, A. Farsi, C. Joulin, and N. Karantzoulis. A class of particulate problems suited to FDEM requiring accurate simulation of shape effects in packed granular structures.
Computational Particle Mechanics, 2019.