How to get the Yield Locus of an Adhesive Powder from a Single Numerical Experiment

Granular materials in a split-bottom ring shear cell geometry show wide shear bands under slow, quasi-static deformation. From discrete element simulations (DEM), several continuum fields like the deformation gradient and stress are computed and evaluated with the goal to formulate objective constitutive relations for the flow behavior. From a single simulation only, by applying time- and (local) space-averaging, yield loci can be obtained: linear for non-cohesive granular materials and non-linear with peculiar pressure dependence for adhesive powders. While the contact model will possibly need additional effects to be included in order to resemble realistic powders, the method how to obtain yield loci from a single numerical test on one material appears very promising and waits for calibration and validation.