Page 87 - The Combined Finite-Discrete Element Method
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70 PROCESSING OF CONTACT INTERACTION
Figure 2.41 Contact force potential defined over the domain of a discrete element of a gen-
eral shape.
Figure 2.42 Contact force potential specified at nodes of a regular grid.
The lines connect points of constant contact force potential. The thicker line indicates
the boundary of the discrete element where the potential is zero. Outside of the discrete
element, the potential is negative. To represent this potential, a regular grid of points can
be employed, as shown in Figure 2.42.
Four points (nodes) of the grid form a square. The potential over the domain of each of
the squares is approximated using the values of the potential at the nodes (Figure 2.43).
In this way, both the boundary (shape) of the discrete element and the contact potential
over a discrete element are approximated using the same regular grid. In the case of the
