Experimental investigation of blast mitigation of pre-fractal obstacles

Obstacles arranged into a pre-fractal shape (Sierpinski carpet) were tested for their blast attenuation abilities using 250 g PE4 at three different scaled distances ( Z = 1.87, 2.24, 2.99 m/kg 1/3 ). Three iterations tested, as well free-field tests comparative purposes. Reductions in peak overpressure up to 26% and specific impulse 19% observed, attributed mechanism known ‘trapping’. This is characterised by reduction the ability of wave advect downstream, with corresponding increases pressure observed within bounds obstacle. Attenuation magnitudes areas reduced found be drastically each iteration, transition from shadowing trapping obstacles more closely resembled true fractals. A linear dependence on newly-defined obstruction factor OF) was arrival time, sensor locations, suggesting that obstacle inherently determinable. The results indicate mitigation fundamentally singular or arrays regular obstacles, could exploited further develop novel protective structures enhanced attenuation.