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DYNAMICS OF IRREGULAR DISCRETE ELEMENTS SUBJECT 201
Figure 5.13 Pebbles in a box: motion sequence after the first contact.
Figure 5.14 Pebbles in a box: ‘Pirouetting’.
on a point. Towards the end of the motion sequence shown in this figure, the pebble,
although attached to the bottom of the box, starts slowly overturning toward the floor of
the box. At the end of this sequence it is sitting flat on the box floor. However, it is still
moving, as shown in Figure 5.15, where the left-hand side pebble hits the right-hand side
pebble, which then moves towards the wall of the box.
Subsequent motion occurs with both pebbles being ‘glued’ to the box floor, but still
moving. This motion is shown in Figure 5.16, and can be best described as ‘rocking’
back and forth.
All the time the energy of the pebbles is dissipated through both friction and material
and contact damping. No damping in the form of external forces has been employed.
