SHAPE REPRESENTATION AND CONTACT DETECTION FOR DISCRETE ELEMENT SIMULATIONS OF ARBITRARY GEOMETRIES

Wen simulating the behaviour of granular assemblies and multi-body sys tems using a discrete element analysis, the shape representation of th e bodies and the contact detection algorithm greatly influence the fle xibility, accuracy and efficiency of the simulation. Several geometric al shape descriptors of two and three dimensional arbitrary rigid bodi es are reviewed and a flexible 3-D descriptor introduced. The aim is t o identify appropriate shape descriptors which allow a variety of type s of bodies to be investigated while ensuring accurate and efficient d etection of interparticle contacts. Polygons/polyhedrons, and continuo us and discrete function representations are examined. The investigati on favours discrete representations due to their efficiency and flexib ility but illustrates the elegance and efficiency of using a continuou s function representation, e.g. a superquadric, to generate discrete r epresentation and simplify the contact detection process.