The Development And Research Of DEM Analysis-design Software Based On Object-oriented Technique

There are lots of granular materials in the nature, and the traditional continuum mechanics method (CMM), which is applied to research the interaction between granular materials and related mechanical parts, can only consider the granular colony as a whole, and it is unable to analyze the movement course of each granular particle and the interaction among the colony. As a result, it cannot resolve the problem very well. Recently when designing the related mechanical parts, the experience and experimentation methods are depended on mostly, and it takes both time and stamina a lot and cannot achieve the expected designing purpose. It is estimated that the abrasion loss of related equipments during the carrying course of granular materials costs 40%, and the demand of optimized design and energy saving is far away from satisfaction. In seventies of the 20th century, Cundall et al. put forward the DEM primarily. The basic thought is to simplify granular colony as a set of particles with a certain kind of shape and mass, and endues the particle-particle and particle-boundary relationship with a certain kind of contact mechanics model and some parameters. The DEM is applied to research the contact effects, which influence the particle-particle and particle-boundary relationship, and the different physical and mechanical characteristics between particle and contacted boundary. The dynamic laxity method, the Newton's Second Law and time step iteration are introduced in DEM to calculate the movement and displacement of each particle, and thus it is especially compatible to resolve the nonlinear problem. Because of these virtues mentioned above, DEM has become a popular method on studying the kinetic problem of granular colony, and it is widely applied in the field of rock engineering and sands flowing; the transportation, mixing, classification of granular materials; the agglomeration and collision of granular materials; the interaction between granular materials and related mechanical parts; the equipment of chemical industry and mine engineering. Therefore the method is popularized to a universal method of multi-arcs particle modeling. The thought of modeling DEM computing course is presented. The DEM computing model is composed of the contacting model, mechanics model, searching algorithm and the methodology and theory of DEM computing, and detailed realization and key technique of each part are depicted respectively. This paper takes an example for AutoCAD, presents a novel thought to establish the DAM from the CAD model of boundary (CAD drawings) based on the redevelopment of AutoCAD, then implements the integration between CAD software and DEM analysis software of related mechanical parts. An integrated analyzing and designing...