@inbook{05bbb763b7b74c21a9aabac524d44835,

title = "Objective constitutive relations from DEM",

abstract = "Powders 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 density, velocity, deformation gradient and stress are computed and evaluated with the goal to formulate objective constitutive relations for the powder flow behavior. From a single simulation, by applying time- and local space-averaging, a nonlinear yield surface is obtained with a peculiar stress dependence. Stress and strain are observed to be not perfectly co-linear, and the difference in orientation seems to be decaying with shear-rate. The anisotropy is always smaller than the macroscopic friction coefficient. However, the lower bound of anisotropy increases with the shear rate, approaching the maximum according to a stretched exponential with a specific rate that is consistent with a shear path of about one particle diameter.",

keywords = "METIS-249692, IR-80340",

author = "Stefan Luding",

year = "2008",

language = "Undefined",

isbn = "9783936310177",

publisher = "Technische Universit{\"a}t Hamburg-Harburg, Germany",

pages = "173--182",

editor = "J. Grabe",

booktitle = "Seehaefen fuer Containerschiffe zukuenftiger Generationen",

}