THE potential for high-speed video to reveal the hidden details of fracture and crush tests is illustrated in a YouTube video posted by Daniel Rittel.
Using a Kirana ultra high-speed video camera from Specialised Imaging, the movie shows a number of impact, fracture, and crush tests performed on ceramic, plexiglass and polycarbonate plates.
The videos were filmed at 1, 2, and 5 million frames per second.
Specialised Imaging says this shows how understanding of these ultra-short phenomena can be improved using the Kirana camera.
Using a proprietary hybrid camera sensor, the Kirana can deliver high resolution and high speed, up to 5 million frames per second, with full video resolution being maintained at all speeds.
Particularly interesting is the sequence showing crack propagation in perspex or plexiglass sheets which have been drilled with a series of holes.
In many cases the crack propagates around an existing hole, rather than joining to it as might be expected.