From elasto-plasticity to visco-elasto-plasticity for saturated granular materials
Document typeConference report
Rights accessOpen Access
A recent extension of the discrete element method is reported for the simulation of dense mixtures of non-colloidal particles and viscous fluids in the non-inertial regime. The numerical model includes sphere-sphere contacts using a soft contact ap- proach , short range hydrodynamic interactions defined by frame-invariant expressions of forces and torques in the lubrication approximation, and drag forces resulting from the poromechanical coupling computed with the DEM-PFV technique . The proposed model is general and applies directly to sheared satured granular media in which pore pressure feedback plays a key role. A partitioned solver makes the algorithm trivially parallel, which enables the coupled problems to be solved with nearly the same wall-clock time as uncoupled dry materials simulations. The shear stress in a dense suspension is analyzed, and decomposed into contact stress and hydrodynamic stress. Both contributions are shown to be increasing functions of a dimensionless shear rate Iv, in agreement with experimental results . In contrast with a popular idea, the results suggest that lubrication may not necessarily reduce the contribution of contact forces to the bulk shear stress.
All rights reserved. This work is protected by the corresponding intellectual and industrial property rights. Without prejudice to any existing legal exemptions, reproduction, distribution, public communication or transformation of this work are prohibited without permission of the copyright holder