Dear clients,
We would like to thank you for your participation to the latest FLAC/DEM Symposium in Lima. It has been an important opportunity for anyone interested in numerical modeling of geomechanics and the broader field of applied mechanics to get together with experts from around the world to exchange the latest developments and experiences.
The issue of this newsletter deals particularly with our introductory training courses planned for the first semester 2016. Let us remind that Itasca also organizes customized training courses to fit individual user needs. Contact us if you have a specific request in term of training or consulting support.
The European Itasca team
 Consulting
Itasca Germany has performed a numerical analysis of a sinter cooling system. Sinter material is falling through a chute system onto a conveying belt, which is 4 m wide, has a diameter of app. 40m and moves with one rotation per hour. After one rotation of the conveying belt, the sinter material drops into an outlet. The sinter material should slowly cool down from initial temperatures of up to 1000°C, and should be evenly distributed on the conveying belt with respect to particle size.
The purpose of the numerical simulation was to verify that the modified design of the chute system would eliminate the segregation effects. The numerical modeling was accomplished using the software Particle Flow Code 3D (PFC3D).
A CAD-model of the chute was imported into PFC. Because the system consisted of several thousand parts, the CAD-model was simplified so that only those parts remained, which can be in contact with the sinter material. Only the first app. 20 m of the conveying belt were built into the model, which was sufficient to get steady state conditions beneath the feeding chute (Fig. 1).
The size distribution of the sinter material had to be upscaled for the simulation, due to the small size of the fines and the resulting huge number of particles. The micromechanical parameters for the numerical simulation were calibrated with an emphasis on the friction angle.
The system was then simulated with a continuous refill of the chute system and a moving conveyor belt, until the material filled the conveying belt, so that a representative size distribution on the belt could be assumed, and the particle size distribution on the belt was analyzed (Fig. 2).
The design of the chute system was then used to build the sinter cooler plant, and after it went to operation, the numerical results have been confirmed. |
Fig. 1: Chute system with sinter material
(color indicates particle size)
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Fig. 2: Particle size distribution on the conveying belt
at the end of the simulation
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Itasca France took part in a national research project on the behaviour of dry stone or weakly bound structures, named PEDRA and funded by the Ministry of Ecology (MEDDE) and the Civil and Urban Engineering Network (RGCU).
The purpose of the study was to model and to explain the mechanical behaviour of a stone arch bridge during the phase of the formwork removal. We compared the numerical results with on-site measurements of the displacement of the arch voussoirs. The formwork removal is the most delicate phase during construction, because it loads the arch, which must work in compression for stability.
Due to the discrete nature of the system, a discrete element method (UDEC, then 3DEC software) was used. This numerical approach has the ability to reflect the specific displacement field pattern observed on-site, which could not have been reproduced with a finite element method. The system has two parts, the arch itself composed of well-adjusted wedged schist blocks (voussoirs) of good quality and the wall spandrel with schist blocks of lower mechanical strength.
The onsite measured displacements showed a singular profile, with a singularity for voussoirs very close to the keystone. The 2D numerical model allowed to explain the observed behaviour: a key feature is the rotation of the voussoirs, which changes the location of the contact zones. Therefore, the contacts between blocks are restricted to small zones for the voussoirs close to the keystone.
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Sketch of the UDEC model performed |
Sensor positions before and after formwork removal,
considering a full length contact and a 20% contact length involving the keystone
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Software
- FLAC 8.0 release
FLAC 8.0 is officially released. All users who prepurchased Version 8.0 will receive in the following weeks the new manuals and executable. Anyone who wants to receive Version 8.0 is invited to contact his Itasca office to upgrade his license.
- PFC 5.0
We remind you that PFC 5.0 was released two year ago and that Itasca converted all PFC 5.0 software to an Annual Maintenance Program. All PFC Suite 5.0 customers were automatically enrolled in this program. The program provides software technical support and bug-fix updates, but most of all this program includes new software functionalities as they become available throughout the year. While enrolled in the AMP, you never have to worry about working with out-of-date software or pre-purchasing the next version of the product. You no longer have to wait for the next major release to take advantage of the newest and greatest features added to PFC.
Do not forget to renew the AMP period if you still want to benefit from these advantages.
- 10% off discount
We have distributed a 10% off coupon to attendees at the 4th Itasca Symposium on Applied Numerical Modeling taking place in Lima at the beginning of March. The coupon is for 10% off Itasca software products if ordered by June 30, 2016.
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Current Updates:
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Training & Seminars
Itasca will host introductory training courses in Europe:
Code |
Location |
Dates |
Contact |
| FLAC3D Training course |
Shrewsbury, UK |
26-28 Avril 2016 |
Itasca UK |
| PFC Training course |
Ecully, France |
18-20 May 2016 |
Itasca France
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| InSite-Lab |
Shrewsbury, UK |
Spring 2016 |
Itasca UK
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| FLAC 8.0 Training course |
Ecully, France |
23-25 June 2016 |
Itasca France |
| FLAC3D Training course |
Ecully, France |
Fall 2016 |
Itasca France |
ITASCA offices regularly organize customized training courses for their clients. The training courses are designed to fit individual user needs and experience. Instruction is available either at Itasca or at the client's location. If you are interested in planning and purchasing a customized software training course, please contact your local agent. |
Conferences
Itasca and/or representative will be attending the following conferences:
Recent Publications
Vatcher, J., S. D. McKinnon and J. Sjöberg (2016) – "Developing 3-D mine-scale geomechanical models in complex geological environments, as applied to the Kiirunavaara Mine", in Engineering Geology, Vol 203, pp. 140–150 (http://dx.doi.org/10.1016/j.enggeo.2015.07.020)
J. J. Oetomo, E. Vincens, F. Dedecker, J-C. Morel (2016) - "Modeling the 2D behavior of drystone retaining walls by a fully discrete element method", in Int. Journal for Numerical and Analytical Methods in Geomechanics, to publish
Sjöberg, J., A. Bolin, A. Sánchez Juncal, T. Wettainen, D. Mas Ivars and F. Perman (2015) – "Input to ore pass design – a numerical modelling study", in Proceedings of International Seminar on Design Methods in Underground Mining, Potvin, Y,. (eds.), pp. 571–584. Perth: Australian Centre for Geomechanics (17–19 Nov, 2015, Perth, Australia)
Tran M. H., Sulem J., Subrin D. and Billaux D. (2015) - "Anisotropic Time-Dependent Modeling of Tunnel Excavation in Squeezing Ground", in Rock Mechanics and Rock Engineering, DOI: 10.1007/s00603-015-0717-y
Ghazal R., Mas Ivars D., Johansson F. and Batres-Estrada R. (2015) - "Back analysis of in situ stress at shallow depth using discontinuum numerical modeling - a case study at the Odenplan station in Stockholm". Proceedings of Eurock 2015, Salzburg, Austria (October 2015)
Moreno J., Senis M. and Olalla C. (2015) "Aspectos necesarios a introducir en la modelización numérica 3D de las presas de escollera con pantalla de hormigón para reproducir correctamente las tensiones en el elemento de impermeabilización ", In X Jornadas Españolas de Presas, Spancold, Sevilla (18-20 February 2015)
Graf F., te Kamp L., Auer M., Acharya M. and W. Wu (2015) – “Soil aggregate stability in eco-engineering: comparison of field and laboratory data with an outlook on a new modelling approach”, in Recent Advances in Modeling Land-slides and Debris Flows. Springer Series Geomechanics and Geoengineering, pp. 29-47.
Wu W., Switala BM., Acharya M., Tamagnini R., Auer M., Graf F., te Kamp L. and W. Xiang (2015) – “Effect of vegetation on stability of soil slopes: numerical aspects”, in Recent Advances in Modeling Landslides and Debris Flows. Springer Series Geomechanics and Geoengineering, pp. 163-177. |
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64 Chemin des mouilles
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