ARUP; ISBN: 978-0-9562121-5-3 - CMBBE 2012 - Cardiff University

4.1 Fracture types from experiments and simulation
Of the 12 tests conducted, eleven fractures were oblique and one was transverse in
nature. Eight of the oblique fractures were of the pattern as shown in Figure 3(a), where
there is a crack diversion in the compression side of impact. These fractures are
observed only in 1.5 m and 1.0 m drop experiments. The other three were of the pattern
as shown in Figure 3(b), where there is no crack diversion in the compression side of
impact. This pattern is observed exclusively in 0.5 m drop tests.
Figure 3 Fracture types observed in experiments.
(a)
Figure 4 shows the comparison between high-speed video and simulation results on
selected frames for the most frequently occurring fracture type.
Figure 4 Comparison between high-speed video frame and simulation for 1.5 m drop. (a) At time
t=0.26 ms: Fracture initiation in lhu13. (b) At time t=0.37 ms (c) At time t=1.1 ms
The fracture type that was observed in 0.5 m drop experiments is shown in Figure 5.
The main difference between this fracture and the one observed in 1.5 m and 1.0 m drop
experiments is that there is no crack diversion seen in the concave (compression) side.
This is also well predicted by the simulation. Thus out of a total of 12 experiments
conducted , fracture type from 10 experiments were predicted correctly. Transverse
fracture was predicted instead of oblique fracture in the remaining 2 simulations.
However the fracture initiation time was predicted in all the 12 cases.
(b)
Figure 5 Fracture type observed in 0.5 m drop experiments
5. CONCLUSION