Blast Wave Mitigation Through Confined Volume and Porous Material

Abstract Over a period of time, the impact of shock waves on human bodies and structures has been studied. To understand the shock wave mitigation over confined volume and porous material, an experimental study is carried out using a shock tube. For the current study, shock velocities ranging from 500 m/s to 650 m/s are created in the tube. The normal shock pressure ranged from 1.1 to 2.8 bar, and the reflected shock pressure ranged from 4.3 to 8 bar in the closed tube. High-frequency PCB pressure transducers is used to measure shock pressure. Three different methods are studied to understand the shock wave mitigation through a confined volume. The methods are perforated bodies with 30%, 40%, and 50% of circular cross section on one side and closed at other end, porous compressible materials kept outside the shock tube to understand head on collision of shock wave and head on shock wave impact on porous material sandwich between the two plates. The number of times the shockwave travelled is highest in the least porous material. On direct shock impact porous compressible material such as glass wool foam, rubber foam is observed to be shredded off, whereas polyurethane foam was comparatively stable. When sandwiching between the two thin plates, it is observed that the shock loading is more on the glass wool foam, less on the rubber foam and the least on the polyurethane foam. It can be concluded that shock waves can be attenuated by perforating bodies, and further impact of the shock can be reduced by materials having blast mitigation properties.