Page 70 - The Combined Finite-Discrete Element Method

IMPLEMENTATION DETAILS FOR DISCRETISED CONTACT FORCE IN 2D 53

(a)

(b)
Figure 2.19 Initial configuration of bar shaped heaps A and B.

4

2

1
3

Figure 2.20 Transient motion sequence for bar shaped heap B.

forces generated, the heap fragments decelerate and move sideways around the obstacle,
forming a spray of fragments behind the obstacle. This contact immediately behind the
obstacle also produces contacts between the fragments further away from the obstacle.
However, these contacts are not able to accelerate the fragments enough to produce
a velocity field that would significantly disturb the shape of the heap. Thus, the heap
disintegrates mainly due to contacts between the obstacle and heap fragments, coupled
with contacts between the fragments which are close to the obstacle.
After initial contact with an obstacle, an almost steady state motion behind the obstacle
is formed, in which the head of the heap disintegrates and the tail of the heap moves