A numerical and experimental approach to blast protection with fluids, effect of impulse spreading

In the face of rapidly evolving challenges, new protection techniques against blast waves generated by high explosive detonations must be identified. The protection of vehicle floors is particularly relevant, especially against improvised explosive devices (IED), as these are challenging to detect. In this paper, investigations on fluid-filled sacrificial claddings are presented. Classical sacrificial claddings aim at limiting the deflection of the target by dissipating the blast wave energy through the core plastic or brittle deformation. On the contrary, fluid-filled sacrificial claddings are systems which aim at limiting the deflection of the target by extracting energy from the system and modifying the load distribution on the target. A new experimental set-up, designed for this investigation, is presented. Based on pressure signals, high speed-imaging and numerical simulations on LS-DYNA, it is shown that the ability to extract energy from the system is directly linked to the freedom of displacement of the fluid. It is also shown that at the same time, higher fluid displacement and well-designed boundary conditions lead to higher impulse spreading on the target.