Modeling shear localization along granular soil–structure interfaces using elasto-plastic Cosserat continuum

All you need is shape: Predicting shear banding in sand with LS-DEM

“…In general, these models work acceptably; however, they fare less well in the commonplace yet complex scenario where strain is localized in regions so small that the granular structure cannot safely be ignored (e.g., landslides, hourglass orifice flow). Models such as micropolar theory [28] inherently possess a length scale that allow them to capture strain localization such as shear banding [38]; however, studies have been limited to 2D conditions [14,53] and many of their parameters' physical interpretations are not known and must be back-calculated from experimental data [15]. Thus, in order to handle 3D strain localization problems, it is generally agreed that an explicit modeling of the particle scale is needed.…”

The importance of Thermo-Hydro-Mechanical couplings and microstructure to strain localization in 3D continua with application to seismic faults. Part II: Numerical implementation and post-bifurcation analysis

“…◆ ◆ ◆ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲▲ ▲▲ ▲▲ ▲▲ ▲▲ ▲▲ ▲ ▲▲ ▲ ▲ ▲ ▲ It is also interesting to explore how the internal length of the Cosserat model affects the response of the system in terms of the stress-strain diagram, the 300 shear band thickness evolution and the shear strain profile (Khoei et al, 2010, Ebrahimian et al, 2012. In Fig.…”

Bifurcation and Degradation of Geomaterials in the New Millennium

“…The enhanced micropolar elasto-plastic Lade's model is used to describe the mechanical behavior of sand (Ebrahimian et al 2012b). The model takes into account sliding and rotating resistances of soil grains, non-symmetric shear stresses, curvatures, couple stresses, pressure level, void ratio and mean grain diameter (Ebrahimian et al 2012b). Mean grain diameter is considered as an internal length.…”

“…Therefore, the results of finite element calculations will be mesh independent provided the element size is small enough (Ebrahimian and Noorzad 2013). The rotating resistance of soil grains along the boundaries of sand layer can be naturally modeled with the additional non-standard Cosserat boundary conditions (Ebrahimian et al 2012b). …”

“…The curvature vector of deformation is given by n κ ij = n ω c j,i . Micro-polar Lade's model, employed in this study, is enhanced through the second stress and deviatoric stress invariants in order to incorporate the internal length (Ebrahimian et al 2012b). The model has a non-linear elasticity function and assumes non-associative flow rule and non-linear plastic work-based hardening function (Ebrahimian et al 2012b).…”