Computational analysis of fluid–structure interaction based blast-mitigation effects

Abstract

Advanced non-linear dynamics, finite element computational methods and tools are utilized in order to assess the blast wave mitigation potential of the fluid–structure interaction phenomena involving rigid and deformable structures. The employed computational methods and tools are verified and validated by first demonstrating that they can quite accurately reproduce analytical solutions for a couple of well-defined blast wave propagation and interaction problems. Then the methods/tools are used to investigate the fluid–structure interaction phenomena involving deformable structures while accounting for both the interaction of the incident blast wave with the structure and for the structure-motion induced blast wave (at the back-face of the structure). To assess the role of the structure deformability, i.e. the role of the shock waves generated within the structure, the results obtained are compared with their rigid structure counterparts. This comparison established that no additional structure-deformability-related blast-mitigation effects are observed in the case of fully supported blast wave loading while, under exponentially decaying blast wave loading, such effects are observed but only under conditions when the shock wave propagation time within the structure is comparable with the incident wave decay time.

Air blast injuries killed the crew of the submarine H.L. Hunley

“…Blast interactions with structures can be prohibitively complex to test experimentally, so these tests are often performed both in air and in water by scaling down the size of the experiment according to the relevant dimensionless parameters [ 17 , 22 ]. G.I.…”

“…Taylor first described the pi groups that dictate the behavior of an underwater blast wave hitting a solid structure with air behind that structure, primarily in an attempt to predict damage to ships from TNT depth charges [ 23 ]. Taylor’s dimensional analysis and subsequent studies by other groups concluded that the amount of momentum transferred into a structure by a blast wave can be scaled by size if the time-relevant parameters of the blast wave are also scaled [ 22 , 23 ]. Dimensionless parameters dictating the amount of momentum transferred are shown as Eqs ( 3 ) & ( 4 ).…”

“…Momentum transfer into a structure produces motion of that structure, and rapid initiation of motion can create a shock wave off the structure’s back surface [ 22 , 25 , 26 ]. Transmitted blast waves have been observed computationally behind structures and experimentally measured behind armor [ 22 , 27 ].…”

“…Momentum transfer into a structure produces motion of that structure, and rapid initiation of motion can create a shock wave off the structure’s back surface [ 22 , 25 , 26 ]. Transmitted blast waves have been observed computationally behind structures and experimentally measured behind armor [ 22 , 27 ]. Computational simulations confirm that backface pressure response is the product of rapid motion of the structure wall in response to the original external blast, and because the motion response of the structure increases for stronger blasts, so will the magnitude of the transmitted blast [ 22 , 25 ].…”

Using Computational Fluid Dynamics (CFD) for Blast Wave Propagation under Structure

“…Explosives such as (TNT) and ANFO when exploded would generate blast waves that can result in extensive damages to the buildings and environments (Ngo et al, 2007). Blast waves can be defined as pressure-based waves propagating in the vicinity of the explosive charge and shock waves serve as the stress-based wave in the protective structure and in turn developed as an outcome of the interaction of structure and blast wave (Grujicic et al, 2013). The interactions of blast wave with an object ignites with an explosion followed by fast chemical reactions.…”