Application Of DEM In Sand Ripple Research

In recent years, all kinds of emerging natural disasters threaten the global environment that humans live on. Desertification, as a global problem, has been eroding the natural environment at an alarming speed and turned out to be a focus for all humans. As a common form, sand ripple has been the center of many researches, the study of which has great scientific value.The thesis conducts numerical simulation based on PFC2D in DEM, builds reasonable contact model in accordance with the contacts between particles without too many proposition designs, and all the calculating processes included are done on the basis of Newton’s second law and Force-displacement law to get the natural movement process till equilibrium, in which displacement continuity and compatibility of deformation are not required. Thus the formulation and development of sand ripple are visualized, which is a breakthrough of traditional studies of sand ripple.In the light of PFC2D in DEM, the paper analyzes the whole process of single-size particles and multi-size particles into sand stack layer till equilibrium. The paper times the history of equilibrium in the two systems, and concludes the change law of porosity in single-size system and multi-size system at equilibrium. Moreover, the specific movement of one single particle is carefully studied by following the track of it in both one-size and multi-size system and the curve diagrams of its movements and further explanation are given in detail, which supply valuable material for further research of sand ripple.