TLSPH example: two rubber rings impact each other

This animation illustrates a simulation of Smooth Mach Dynamics (MACHDYN package) where two objects using a grid-free continuum model (the particles are the equivalent of the grid points of a mesh-based model), representing rubber rings, are pushed toward each other and then bounce back. The green ring on the left is represented by a plastic model and retains its deformation while the red ring on the right is represented by an elastic model and recovers its shape.

The special graphics gimmick here is the use of the fix graphics/isosurface command to represent the continuum shape of the rings. The refined surface, generated with the marching cubes algorithm, is then passed to the LAMMPS dump image command to render it as continuum objects. For illustration, the constituent atoms are also rendered and shown “inside” the translucent isosurfaces.