Computational modeling of confined blast waves with focus on interaction with structures

Abstract

Blast loading is a critical extreme loading condition for most engineering structures. Modeling such scenarios is challenging due to the intrinsic non-linearities. Recent numerical methods can capture the physics governing blast waves and their interaction with structures in a more accurate way than established empirical methods. This article is intended as a proof of concept that state-of-the-art CFD and FE software can be combined to set up high-fidelity uncoupled simulations. Computational fluid dynamics is exploited in this work to map the pressure field developed during a detonation reaction in a Eulerian domain. Then, such pressure time history is applied in the finite element framework to perform Lagrangian simulations. The methodology is used to compare the structural response of blast-loaded plates in fully confined environments to that in free-field scenarios. It turns out that confined blast waves are more severe than blast waves in unconfined scenarios, mainly due to the multiple reflections and residual quasi-static pressure. Moreover, on the one hand, the quasi-static pressure appears to contribute to further increasing the plate out-of-plane deflection, while on the other hand, it prevents plates from undergoing reverse buckling or oscillations around the initial equilibrium configuration. Experimental tests are required to provide further evidence about the latter contribution.