A method for representing boundaries in discrete element modelling—part II: Kinematics

Abstract

SUMMARYThe application of the DEM to engineering problems involving the dynamic behaviour of discontinuous media has necessitated the introduction of moving boundary surfaces. In this paper a method is presented for modelling three-dimensional moving boundary surfaces within the discrete element framework. The surfaces of boundary objects are discretized into triangular planar surfaces using the ÿnite wall method. Wall elements are grouped and each group is associated with a single discrete boundary object which may move independently. Movement comprises any combination of translation and rotation of wall element groups, subject to a given acceleration and velocity during a calculation cycle. The scheme is explicit due to rigidity of the wall elements which are stationary ÿxed in position and orientation over a time step. Any in-plane velocity is handled as a contact point velocity within a calculation cycle. The kinematic conditions at each calculation cycle may be pre-deÿned or returned from a separate calculation of rigid body motion of the boundary object. The method provides a means for coupling sphere-based particle dynamics with rigid body dynamics and structural analysis of boundary components.

Validation of Particle Size Segregation of Sintered Ore during Flowing through Laboratory-scale Chute by Discrete Element Method

“…The speeding-up of DEM is possible to optimize the particle detection process [9][10][11] and the program tuning, 12) which were proposed by the authors. The multi-sphere or ellipsoidal particles are the commonest solutions for considering particle shape in DEM, [13][14][15][16][17][18] and the usual commercial software packages have this kind of tool. However, it needs huge calculation time, therefore, the method for considering the effect of particle shape on flowing behavior with low calculation load is necessary for the large-scale calculation in the ironmaking process.…”

Numerical analysis of contact electrification of non-spherical particles in a rotating drum

“…The cylindrical drum with a 3 mm diameter and 5 mm length is discretized into 504 triangular meshes. The contact interactions are detected and applied between particles and each triangular mesh [35]. Initially, 300 (multi-sphere) particles are deposited on the cylindrical surface of the drum until the granular bed is stable (i.e.…”

Development of a discrete element model with moving realistic geometry to simulate particle motion in a Mi-Pro granulator

“…Contact between the discrete triangular elements and the spherical particles can be determined by the finite wall method of Kremmer and Favier (2001a). These authors also described how to incorporate moving parts into DEM models (Kremmer and Favier, 2001b). Although finite element meshes allow for representation of very complex geometries and can handle movement of internal parts, the drawback is computational expense.…”