A packing generation scheme for the granular assemblies with 3D ellipsoidal particles

This paper introduces a new generator algorithm and computer program for 3-D numerical simulation of packing configuration in a granular assemblies composed of ellipsoidal particles of different a/b aspect ratios. Each ellipsoidal particle is approximated by the revolution of an ellipse, formed by four connected arcs, about the major axis passing through its centroid. The centroid co-ordinates, major axis direction and lengths of the major and minor axes are the essential data for the packing generation and associated contact detection. The domain to be filled with particles can be a polyhedron of any shape. The packing program was coded based on a newly proposed scheme which obeys the no interpenetration kinematics of solid bodies. New contact detection algorithms for any two ellipsoids in the packing space were developed. Though simple, these algorithms effectively determine the contact condition and contact point without solving the simultaneous equations of the two ellipsoidal surfaces. Each particle's packing location, contact-point co-ordinates, and three-dimensional graphs can be created using the packing domain given boundaries, along with numbers, and geometrical information of particles to be generated. Simulation results show that this new algorithm provides an effective packing model as a required initial input for analysing the mechanics of granular material. This generation scheme potentially can explore the complex 3-D behaviours of material composed of discrete particles. Copyright © 1999 John Wiley & Sons, Ltd.

[1]  K. Walton,et al.  The effective elastic moduli of a random packing of spheres , 1987 .

[2]  Sia Nemat-Nasser,et al.  A statistical study of fabric in a random assembly of spherical granules , 1982 .

[3]  Richard J. Bathurst,et al.  INVESTIGATION OF MICROMECHANICAL FEATURES OF IDEALIZED GRANULAR ASSEMBLIES USING DEM , 1992 .

[4]  Richard J. Bathurst,et al.  Numerical simulation of idealized granular assemblies with plane elliptical particles , 1991 .

[5]  Vei-Chung Liang,et al.  A PACKING GENERATION SCHEME FOR THE GRANULAR ASSEMBLIES WITH PLANAR ELLIPTICAL PARTICLES , 1997 .

[6]  J. Ting,et al.  Discrete numerical model for soil mechanics , 1989 .

[7]  M. Satake.  A discrete-mechanical approach to granular materials , 1992 .

[8]  T. Ng,et al.  A three-dimensional discrete element model using arrays of ellipsoids , 1997 .

[9]  P. Cundall,et al.  A discrete numerical model for granular assemblies , 1979 .

[10]  John M. Ting,et al.  A ROBUST ALGORITHM FOR ELLIPSE-BASED DISCRETE ELEMENT MODELLING OF GRANULAR MATERIALS , 1992 .

[11]  T. Ng,et al.  Contact detection algorithms for three-dimensional ellipsoids in discrete element modelling , 1995 .

[12]  Richard J. Bathurst,et al.  Micromechanical features of granular assemblies with planar elliptical particles , 1992 .

[13]  M. Sadd,et al.  a Discrete Element Study of the Relationship of Fabric to Wave Propagational Behaviours in Granular Materials , 1997 .

[14]  R. Bathurst,et al.  Micromechanical Aspects of Isotropic Granular Assemblies With Linear Contact Interactions , 1988 .