Shear-band analysis in idealized granular material

Two-dimensional particles experience shear bands as real granular materials; they form a convenient vehicle to investigate shear bands within granular soils. Numerical simulations on these idealized materials are used to assess the assumptions and limitations of the shear-band analyses that are based on linear stability theory and micropolar continua. These shear-band analyses are found to be applicable in the postbifurcation range, and they describe the thickness of shear bands and the displacements and rotations of the particles within the shear bands of idealized granular materials. The influence of particle rotation within shear bands validates the use of micropolar models. The thickness of shear bands is strongly influenced by the model parameters controlling the micropolar effects. The constitutive models based on the deformation and flow theories of plasticity predict similarly the emergence and inclination of shear bands, but give different shear-band thicknesses.