Study of Blast Wave Pressure Modification through Rubber Foam

The study of different porous and granular materials like polyurethane foams, aluminium foams, aqueous foam, sand, saw dust etc. for shock mitigation have been reported in literature using shock tubes. But the shape of explosively generated blast wave is different from the shock wave generated using shock tubes. The present paper deals with the study of generation of blast waves in laboratory using a blast wave generator. The blast wave generator is a shock tube with high pressure (Driver) and lower pressure (Driven) sections separated by a solid metal diaphragm. In this, the blast wave profile is produced within the tube by adjusting the driver section length. Then modification of blast wave pressure through open cell rubber foam is studied by varying the thickness of foam sample. The results show that the presence of the foam initially amplifies the end plate pressure as reported in the literature. But with increase in the foam thickness the end plate pressure starts decreasing and finally mitigation is observed for foam thickness more than the critical thickness.