Numerical investigations on the role of the μ(I) viscoplastic rheology and the 3D frictional effects on a granular column collapse on large slopes - Laboratoire des Sciences des Procédés et des Matériaux Accéder directement au contenu
Pré-Publication, Document De Travail Année : 2015

Numerical investigations on the role of the μ(I) viscoplastic rheology and the 3D frictional effects on a granular column collapse on large slopes

Résumé

The present work focuses on the modeling of dry granular flows in the context of the granular column collapse in an inclined channel and detailed comparison with experimental thickness profiles and front velocities. A nonlinear Coulomb friction term, representing the friction on the lateral walls of the channelis added in the model, providing the ability to accurately simulate this column collapse on large slopes (up to 22 ◦ ). We demonstrate that accouting for lateral friction effect in the simulations is crucial at large slopes (higher or equal to 16 ◦ ). In other respect, we show that a Drucker-Prager constant viscosity model with a well-chosen value for the viscosity is able to predict the slow propagation phase at large slopes, experimentally observed, whereas the viscosity provided by the μ(I) rheology, evaluated from physical quantities, does not behave as well. Finally, we show that the present model predicts the appearance of shear bands in the bulk when refining the mesh. This behaviour appears to be unstable (as it induces shear bands as narrow as 4 grain diameter, to the best of our refining capacities) but is not affecting the simulations in terms of velocity range and free-surface movements. We also show that this effect is triggered by the coupling of the plasticity criterion with the pressure field.
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Dates et versions

hal-01204716 , version 1 (24-09-2015)
hal-01204716 , version 2 (16-10-2015)
hal-01204716 , version 3 (25-07-2016)
hal-01204716 , version 4 (19-11-2016)

Identifiants

  • HAL Id : hal-01204716 , version 1

Citer

Nathan Martin, Ioan Ionescu, Anne Mangeney, Maxime Farin. Numerical investigations on the role of the μ(I) viscoplastic rheology and the 3D frictional effects on a granular column collapse on large slopes. 2015. ⟨hal-01204716v1⟩
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