Not continuum mechanics

Old sand regeneration process, we can see it as a discrete solid movement, because the large number of sand, grit unequal size, shape differences of factors, it is clear sand regeneration process is a complicated process. Predict sand flow characteristics of the following two main aspects: First, continuum mechanics, mechanism in the continuous medium, the problem is over-reliance on a simplified, the nature of the constitutive equations required, while ignoring the nature of  polycrystalline diamond  particles; Second, do not continuum mechanics methods, such as discrete element method, the method is the main idea of ​​the whole system is seen as a series of separate particles of units, each unit itself has a certain geometrical and physical characteristics. Is the use of algorithms and discrete element displayed differential theory developed micro / meso-mechanics program, it is the structure of elementary particles from the media point of view of basic grinding wheel  characteristics of the medium, and that in a given medium under different stress conditions depends mainly on the basic characteristics of the contact between the particles change of state for the study of the fracture and cracking granular aggregates development issues and particle flow (large displacement) question.