BLAST PRESSURE MITIGATION USING PERFORATED PLATES

Abstract

The detonation of an explosive system creates high-pressure blast wave in the adjoining media. The interaction of blast wave can inflict severe injuries to humans and catastrophic damage to structures. Many materials such as foams, soil etc., and techniques e.g. reflecting plates, perforated plates, and metallic grids are studied in literature to mitigate the deadly effects of blast waves. In the present experimental study blast wave generator (a short driver section shock tube) is used for the evaluation of blast pressure mitigation in perforated plates of different blockage ratios and hole configurations. These plates with blockage ratio (BR) from 78.79% to 93.43% were deployed inside the driven section of the blast wave generator at a suitable distance from the diaphragm so that blast wave loading occurs on perforated plates. The strength of transmitted blast wave through different plates is measured in terms of peak over pressure using piezoelectric pressure sensors deployed downstream at 0.2m and 0.48 m distances from the perforated plates. The measured strength of the incident blast wave was found to reduce by about 36% to 65% at 0.2 m and about 37% to 73% at 0.48 m downstream through different blockage ratio plates. It was observed from the recorded data that transmitted pressure decreased with an increase in blockage ratio. In the case of the same blockage ratio, the decrease in pressure for a plate with circular holes was more in comparison to a plate having triangular holes and a central hole.