Page 139 - The Combined Finite-Discrete Element Method

122 CONTACT DETECTION

z

y

x
Figure 3.57 Singly connected lists for layers of cells represented by two integer arrays.

• One-dimensional array Z of size N integer numbers (Z[N]), where N is the total
number of discrete elements, represents for each discrete element the next discrete
element that is in the same singly connected list (Figure 3.58).

Once all the lists for the z-layers of cells have been formed, they are considered to be
‘new lists’. To locate a non-empty list, a loop over all discrete elements is performed:

Loop over all discrete elements (i=1; i≤N;i++)
{ calculate integerised coordinate

z − z min
i z = Int (3.75)
d
if the z iy list is marked as “new”:
{ mark it as “old” and call it central z-list
}
}
and a particular ‘new list’ found is marked as an ‘old list’.

Integer array C

−1 −1 −1 −1 5 9 7 2 −1 −1

−1 −1 −1 1 −1 3 4 6 8 −1

Integer array Z

Figure 3.58 Layers of cells with all discrete elements in a particular layer i z being represented
by a singly connected z-list z iz .