Page 64 - The Combined Finite-Discrete Element Method

IMPLEMENTATION DETAILS FOR DISCRETISED CONTACT FORCE IN 2D 47

0.4 m

0.3 m
V = 900 m/s
1 m

9.6 m

Figure 2.9 Beam-shaped heap of rigid fragments.

(a)

(b)

(c)

(d)
Figure 2.10 Beam-shaped heaps of fragments. Heap A–80 fragments, heap B–320 fragments,
heap C–1280 fragments, heap D–5120 fragments.

moving at an initial velocity of 900 m/s. Four heaps of the same shape and size were con-
sidered (Figure 2.10). Heap A is made of a smaller number of relatively large fragments,
while heaps B, C and D are comprised of a larger number of smaller fragments.
The transient motion of Heap A is given in Figure 2.11. Initially, all of the 80 heap
fragments are at rest. As the projectile approaches the heap, contact between the projectile
and fragments produces acceleration of the heap fragments and deceleration of the projec-
tile. Also, interaction between the heap fragments themselves results in fragments further