The correct representation of bulk materials depends on many factors, one of which is the particle shape. In many cases, spheres with additional physical properties (e.g., rolling friction) are a good choice, but often also nonspherical particles are used. Aspherix® offers a wide range of them, comprising multispheres, flexible, bonded particles, superquadrics (tablets, boxes, cylinders, …) and also triangulated objects.
Simulation with A and X shaped particles in a rotating drum. The usage of concave particles allows for an accurate representation of the bulk material.
Real convex shapes without inward facing components can be imported easily from 3D CAD files.
SPH, FEA, MBD, Wear
Shape effect – multispheres vs spheres:
In Aspherix™, fibers are modelled as multi-spheres bodies with elasto-damping interparticle forces (normal and tangential).
Rolling wheel on grass
In this video, the grass leaves, modelled as fibers, are bended by a rotating wheel. After being bent, the fibers tend to move to their original configuration due to the interparticle forces.
Bonded particles can be used to generate custom shapes like pellets, ellipsoids etc. The mechanical properties of the assemble depend on the bond breakage criterion, normal and tangential stiffness of the bonds, energy dissipation of the bonds and properties of the spherical particles.
This video shows a flexible membrane that consists of spherical particles. This is a specific application case of a cohesion model.
Filling and emptying of a cylinder with superquadric particles.
Prismatic spouted bed – simulation with triangulated particles.