Page 107 - The Combined Finite-Discrete Element Method

90 CONTACT DETECTION

total number of cells. All these integer numbers are best represented by a two-dimensional
array of integer numbers (called a screening array):

 
c 1,1 c 1,2 c 1,3 ... c 1,j .. . c 1,n cel
 c 2,1 
 
 c 3,1 
C =  ...  (3.29)


 i, j 
 c i,1 
...
 
c n cel ,1 c n cel ,n cel
Mapping of discrete elements onto the cells is represented by associating a singly con-
nected list of discrete elements with each cell. The first discrete element in the list (head
of the list) is represented by array C(short for cell), while the rest of the list is represented
by the integer array called E (short for element).
As each discrete element is mapped to one and only one cell, E is a one-dimensional
array of size N,where N is the total number of discrete elements comprising the discrete
element system, i.e.

E = e 1 e 2 e 3 ... e i .. . e N (3.30)

For the discrete element system shown in Figure 3.19, the representation of mapping of
discrete elements onto cells is achieved by setting array C to point to the heads of singly
connected lists for each of the cells, i.e.

10
9

8
•5
7 •7 •4
9• •3 •1 •2
•6
6 •8
5
4
3

2
1
1 2 3 4 5 6 7 8 9 10

Figure 3.19 Mapping of discrete elements onto the cells for the screening contact detection
algorithm.