From discrete element simulations towards a continuum description of particulate solids

摘要: The description of the behavior particulate materials relies on constitutive equations, functions stress, strain, and other physical quantities describing system. It is rather difficult to extract macroscopic observables like stress from experiments—for example, in a two-dimensional (2D) geometry with photo-elastic material, where visualized via crossed polarizers. alternative is, perform discrete element simulations average over microscopic simulation, obtain some averaged quantity. averages scalar density, velocity, particle-spin are straightforward, but for deformation gradient, one finds slightly different definitions literature. This chapter briefly introduces boundary conditions model system, before presenting averaging procedure. Kinematic dynamic system obtained simulation data material properties determined as combinations observables.