A History of Research and a Review of Recent Developments

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Pressure measurement and blast simulation
camera working by electrically operated remote control from a blast proof
building a short distance from the rig; a few milliseconds later the camera
operated an electrical charge-firing circuit. The moment of firing was recorded
by a flash on the film from a photoflood bulb operated by the firing circuit.
The camera speed was 3000 frames per second, with a running time of about
3 sec, including acceleration and deceleration. The time interval from firing
to complete decay of the blast pressure was about 20 msec. Blast pressures in
the tube were measured by piezo-electric gauges.
A dimensionally similar vertical shock tube was constructed at the US Air
Force Weapons Laboratory, Kirkland, New Mexico, in the 1960s, and has
been described by Abbott [6.9]. Detonation was by means of 4.57 lb of
primacord, and the shock pressure was applied to a cylindrical soil bin 48 in
high, 22 in diameter.
Another type of vertically set apparatus for simulating blast loads was
built at the US Waterways Experiment Station at Vicksburg, Miss. USA, and
has been described briefly by Flathau, Dawsey and Denton [6.39]. It consisted
of a vertical cylinder, containing a piston that could be hydraulically actuated
to provide short duration concentrated loads over a maximum stroke of 4 in.
Tests showed that loads in excess of 200 000 lb could be applied with a minimum
rise time of 1.3 msec with a movement of about 0.25 in of the loading ram. A
second version of this vertical loading system, operated in a similar way, was
capable of applying loads of 500 000 lb over a time of 80 msec.
Figure 6.10 Large blast load generator at the Waterways Experiment Station, USA
(from Flathau et al., ref. 6.39).