Study On Model Of Dry Particulate Contacts By Distinct Element Method & Visual Programming On PC

The Distinct Element Method (DEM) is an efficient numerical calculating methods in solving problem about disperse particles system, and compensates the insufficiency of continuum mechanics in the same field. Although there are lots of work to do in the research and application of DEM, and the result obtained is some proximate, it is really the most efficient method in disposing particles system by nowadays. The fundamental principle of DEM is introduced in this paper, and the calculation of normal or tangential contact force with adhesion or without adhesion between sphere particles is discussed. The reasonable parameters in DEM and its affection to calculation precision is discussed at the same time. For readers to understand the realization of DEM more clearly, the DEM program which will be adapted in the paper is introduced in detail in aspect of general structure, programming thinking, data restoring, iterated calculation, and the calculation of time step. Because large capacity and high calculating speed of computer are requested for DEM program, the Workstation which is also superiority in plotting is the first choice for giving system environment. But following the rapid development of computer technology, the restore capacity and CPU speed of Personal Computer with superior plotting function have been raised remarkably in aspect of hardware, and the excellent developing platform has strengthened the dialogue between the user and the computer in aspect of software. So a DEM program with visualization function is developed in the paper, which keep all of its function running in Workstation and enlarge the number of particles simulated with more highly calculating speed. By the way, the advantaged functions of plot operating, plot storing and printing of, dialoguing with computer, querying the simulation results and data analyzing have not been presented in the previous version. The adapted Visual DEM Program is used to simulating the proceeding of particles transportation by vehicle, which is related in the last part of the paper. By simulating, the movement of particles during its carrier is decelerating, the contact force between particles and the impacting force on vehicle from particles could be recorded in database so as to be analyzed in detail.