Blast characterization using a ballistic pendulum with a centrally mounted Hopkinson bar

A series of laboratory-scale blast characterization experiments are presented to show the degree to which two alternative configurations of an instrumented ballistic pendulum can provide an ideal impulsive load. Both the total impulses and blast pressure histories were captured, the latter using a centrally mounted Hopkinson bar. Repeatable and consistent total impulse values were achieved, while the Hopkinson bar technique was sufficient to capture the essential shape of the blast loads, although the fine detail of the peak pressure could not be resolved due to higher mode dispersion. A short stand-off configuration produced short duration blast loads that approached an ideal impulsive load condition with near uniform impulse distributions, although the blast pressure distributions were non-uniform. Conversely, a blast tube configuration produced blast loads with near uniform pressure and impulse distributions but did not approach an ideal impulsive load condition, that is, the pressure history must be accounted for in subsequent analytical work.