WhoIsDoingWhat

Who is doing what

Václav Šmilauer

About me

• Former PhD student at CVUT Prague & UJF Grenoble
• Currently freelancer

Field of interest

• Discrete concrete models for elastic, non-elastic (incl. damage) behavior & applications
• Software engineering

Working on

• CPM (Concrete Particle Model), in pkg/dem/ConcretePM.?pp; python scripting; performance; parallelization
• Moved over to the WooDEM fork of Yade, as freelancer

Annoying bugs/missing features

• Badly scalable collider -- for >50k particles, collider takes over 80% of simulation time! (there are O(n) algorithms (Munjiza's NBS, for instance) but not implemented in Yade. Do you have a master student to work on that? Quite nice topic for master's thesis.
• Lack of documentation for many classes, lack of documentation for yade in general
• Duplicated code, unfinished/dirty code, undocumented code, deprecated code. Shouldn't we do some review of all code for docs, functionality and hacks?

Vincent Richefeu

About me

• Assistant Professor at the University Joseph Fourier

Field of interest

• (until now) wet granular materials
• micro-mechanics and physics
• DEM (MD-like and CD approaches)
• Force laws (called constitutive laws in yade)

Working on

• Avanlanches
• generation of sphere packings

Annoying bugs/missing features

• I don't feel good with interaction parameters that are stored (embeded) in bodies
• Lack of design documentation (although there are very usefull documents written by kindly people)

Bruno Chareyre

About me

• Assistant Professor in Grenoble University (INPG)

Field of interest

• DEM and DEM-fluid couplings (capillary effects and internal flows)
• micro-mechanics and homogenization in granular materials
• modelling of snow creep
• multiscale approaches

Working on

• Triaxial testing
• Contact laws (CohesiveFrictional, VolumicLaw,...)
• Solving flow equations efficiently in coupled problems
• Usage of triangulation in Yade (contact detection, local strain, volumic law, fluid flow)

Anton Gladky

About me

• Work on PHD in TU Bergakademie Freiberg
• Mining Engineer (grad.2004, National Mining University, Ukraine)

Field of interest

• DEM modeling of mining rocks, implementing it in YADE
• Mining rocks behaviour in high pressure grinding machines

Working on

• RockPM (Rock particle module)
• Packing scripts

Emanuele Catalano

About me

• PhD Student in Grenoble INP
• Geotechnical Engineer (grad. 2009, Politecnico di Torino, Italy)

Field of interest

• Discrete Element Modelling
• Coupled fluid - solid problems

Working on

• A flow solver engine to be implemented in YADE

Annoying bugs/missing features

• LACK of documentation? Initiation of a 'Level 2' guide will come soon. I'll do my best.

Roger Arnold

About me

• Graduate student in Environmental Engineering at Virginia Tech in Blacksburg, VA

Field of interest

• River Mechanics
• Water Quality

Working on

• Incipient motion and transport of sediment in turbulent flow

Annoying bugs/missing features

• Lack of documentation (has made it difficult for me to learn YADE with no prior DEM experience )
• It would be nice to have more DEM-fluid coupling in YADE

Janek Kozicki

About me

• Assistant Professor at the Gdańsk University of Technology

Field of interest

• software engineering and C++ design
• discrete modeling

Working on

• Development_schedule, albeit so slowly you almost don't ever notice
• Lattice model
• Polyhedron collisions

Annoying bugs/missing features

• there isn't a single person who gets paid for yade software development, we all have to do our "own research" having no time to improve the tool that everyone uses.
• coding style and naming inconsitencies
• not using boost serialization
• not using boost units
• our yade website is a mess, and there are many of them! This one, some other on wikidot (?) some leftovers on berlios, and something on launchpad. And maybe even few more.

Sergei Dorofeenko

About me

• Cand. Sci. (Phys.-Math.)
• Researcher at the Institute of Problems of Chemical Physics RAS, Chernogolovka, Russia

Field of interest

• Simulation of multiphase flows with chemical reactions
• Filtration Combustion
• Discrete Element Modelling (MD-like)
• Computational Fluid Dynamics

Working on

• Coupling DEM (YADE) and CFD (OpenFOAM) for coupled granular-fluid flows.
• Using triangulated surfaces to define the walls
• Parallelization
• Performance

Annoying bugs/missing features

• Lack of documentation
• Coding style and naming inconsitencies
• Lack of regression tests
• Need more performance
• Removing particles from simulation?

Feng Chen

About me

Geotechnical Engineer at HNTB Federal, Baton Rouge, LA (http://fchen3.googlepages.com/home)

(Recently graduated from PhD program in Department of Civil and Environmental Engineering, University of Tennessee, Knoxville)

Field of interest

• Fluid-Particle interaction using Tsuji's (1993) method
• Seepage flow in granular material
• Fluidized bed
• Application of DEM in chomratography column

Working on

YADE-DEM and OpenFOAM coupling, and planning to release YADE-OpenFOAM coupled code in the near future with verified examples and documents.

Looking for a good application of DEM-CFD not only in the research field.

Annoying bugs/missing features

Steep learning curve, Linux platform made it difficult to get more people join in.

Dang Hoang Kien

About me

• PhD student at McGill University

Field of interest

• Coupling DEM&FEM with application in geomechanics

Working on

• FEM package for YADE using explicit solver, currently includes tetaherdon (4, 9 nodes with 1,4 and 5 Gauss points), hexahedron (8 nodes, 20 nodes with 1 and 8 Gauss points). (done but only compatible with old version)
• Collider and packing algorithms. (compatible with old version)
• Coupling DEM&FEM using interface and bridging domain

Annoying bugs/missing features

• Basic classes (and even not the basic classes) are often changed so other users may not want to update to the most-to-date version. It limits the advantage of the new version.

Luc Sibille

About me

• Lecturer at the University of Nantes (France)

Field of interest

• DEM and DEM-fluid coupling (internal flows)
• physical models with analogic materials (e.g. Schneebeli cylinders)
• failure in granular matter
• internal erosion in soils

Working on

• Triaxial testing
• Implementation of LBM in Yade to solve fluid dynamic flows
• Degradation/modification of the granular assembly at the grain or contact scale

Annoying bugs/missing features

• We need a dedicated research engineer to boost Yade development
• Definition of the simulation in one big xml file (even if there is Python), what about three files: a file to define the loading programme, a second file to define the geometry and a third file to define the interaction parameters.

Jérôme Duriez

About me

• Temporary Assistant professor in 3S-R, Grenoble

Field of interest

• Mechanical behaviour of rock joints
• Rock (in)stabilities

Working on

• various loading Engines, in rock joints experiments framework
• contact law, including momentum transfert

Annoying bugs/missing features

• I would see, as Luc Sibille, interest in splitting .xml files

Luc Scholtès

About me

• Post-doctoral fellow at CSIRO - Earth Science and Resource Engineering

Field of interest

• Hydro-Mechanical Couplings (unsaturated and saturated flows)
• Rock Mechanics
• Micro-Mechanics and Homogenization in granular materials (multi-scale approach)

Working on

• Triaxial Testing
• Contact Laws (CapillaryCohesiveLaw, RockJointedLaw...)
• Texture effects on macroscopical behaviour
• Geometry Import (Discrete Fracture Network)

Annoying bugs/missing features

• We need a dedicated research engineer to boost Yade development

Jingsong Chen

About me

PhD student in Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, TN, USA

Field of interest

• Hot Asphalt Mixture packing;
• Asphalt Concrete cracking and strength;
• Creep of Asphalt Mixture;
• Pavement material experiment simulation (like APA, IDT)

Working on

Hot Asphalt Mixture packing simulation by using YADE, and planning to do some research on Asphalt Concrete cracking and strength;

Annoying bugs/missing features

• Compatibility of different version;
• Insufficient example and document;

TRAN Van Tieng

About me

• PhD Student at the University of Grenoble (France)
• Invited Student at CSIRO - Earth Science and Resource Engineering (Brisbane,Australia)

Field of interest

• Discrete Element Modelling
• DEM-fluid coupling (unsaturated and saturated materials)
• Mechanical behaviour of Concrete

Working on

• Triaxial Testing
• Contact laws (Elastic-Hardening-Damage constitutive law with a non linear relationship between forces and displacements)
• Modelling of the unsaturated and saturated concrete's behaviours under high confining pressure (up to GPa)

Chiara Modenese

About me

• PhD Student in Engineering Science, University of Oxford, UK
• Structural Engineer (2009, University of Padua, Italy)

Field of interest

• Discrete Element Modelling
• Contact Mechanics
• Constitutive modelling of granular materials
• Numerical modelling of lunar soil

Working on

• Triaxial test numerical simulations
• Contact laws (HertzMindlin, contact law in the presence of adhesion)

Viet Tran

About me

• PhD Student in Geotechnical Engineering, McGill University, Canada

Field of interest

• Discrete Element Modelling
• Coupled Finite Element/Discrete Element Method
• Numerical modelling of geotechnical problems

Working on

• Interface between DEM and FEM
• Coupled FEM/DEM in tunneling

Klaus Thoeni

About me

• PostDoc at The University of Newcastle, Australia

Field of interest

• Numerical methods (DEM, BEM, FEM)
• Coupling of different methods
• Rock fall analysis and rock mechanics
• Tunnelling and underground constructions
• Structural analysis

Working on

• Implementation of a particle model for double-twisted rock fall nets (WirePM)
• Interaction model between rock fall net and rock boulders

Annoying bugs/missing features

• Undocumented code and deprecated code
• To many yade related websites. Informations often do not coincide or are duplicated!
• Mess of scripts in the trunk version! Many scripts do not run mainly because the code is updated at some stage but nobody updates the scripts.
• Missing list with favourite features! Let me start...

Favourite features

• Open source
• Linux based
• Integration of python
• Great flexibility in adding your own contact law etc.
• Easy pre- and post-processing

Christian Jakob

About me

• PhD at TU Bergakademie Freiberg, Germany

Field of interest

• Numerical investigation of soils with Discrete Element Method on microscale
• Hydromechanical coupling methods (continuum-discrete, DEM-SPH, DEM-LBM)

Working on

• Micromechanical investigation of sandy soil under increasing water level
• Capillary effects in an unsaturated granular material
• Triggermechanisms for liquefaction without external stimulation

Favourite features

• Clumps within periodic space
• Simulation Inspection

Jan Stránský

About me

• PhD student at CTU, Prague, Czech Republic

Field of interest

• Concrete modeling
• Numerical modeling in general

Working on

• Development and improvement of concrete model in Yade
• DEM-FEM coupling

Favourite features

• Python
• Open source
• Clumps
• Interaction masks