Blast protection of vehicle underside through fireball extinction by water

Abstract

The aim of this research is the study of blast mitigation using water within the context of underbelly vehicle protection. The interaction of a shock wave generated by an explosive charge, with a relatively small quantity of water, in a vehicle underside environment has been investigated. The simulant vehicle underside was almost a cube with open side faces and a volume of about 7 m3. The deformation of target plates bolted onto the vehicle simulant floor was assessed. These were either unprotected or protected by plastic bags filled with water. Three quantities of water were tested: 4, 10 and 15 kg. Both the residual deformation of the test plate and the maximum dynamic deformation were assessed. This latter was obtained by the squeezing of a hexagonal aluminum tube and by digital image correlation. The results showed that both deformations, residual and dynamic, of a 5 mm thick steel plate decreased when it was protected by water. Water was more effective in reducing deformation parameters than using an equivalent mass of steel. The protective effect of water was also tested with a 1 kg TNT equivalent charge in a steel-pot on a 5 mm thick armor plate. In this case as well, it could be shown that for both deformations – residual and dynamic - the armor plate was less deformed when protected by water.