Blast wave propagation in survival shelters: experimental analysis and numerical modelling

Abstract

The propagation of blast and shock waves in confined environments is a complex phenomenon; yet, being able to derive valid predictions of such phenomena is highly relevant, for example, when it comes to the assessment of protection of personnel in military environments. This study looks at the propagation of blast waves inside a compound survival shelter. Experimental analyses are performed on a small-scale model of the actual configuration of the shelter subjected to the detonation of an explosive charge at different locations close to its entrance. Pressure-time signals are recorded on a number of locations in the model. A numerical model is also developed to complement the experimental program, based on the explicit finite element (FE) code LS-DYNA. The recorded experimental data (e.g., pressure and impulse) are compared with the numerical predictions to validate the FE model. The authors discuss two different modelling approaches (the Lagrangian and the MM-ALE formulations) and analyse the influence of using a different number of ambient layers, the advection method, the time-step size, and level of discretisation. The proposed numerical model predicts and captures the relevant stages of the propagation of the shock wave very well, with error levels on the resulting specific impulse always lower than 19% when compared to the experimental observations. Keywords Blast wave • Shock wave • Small-scale models • Confined explosions • Experimental analysis • Numerical modelling • LS-DYNA

Structural response of corrugated plates under blast loading: The influence of the pressure-time history

“…The work is divided in two main parts: the influence of different parameters concerning experimental pressure signals measured by Cac ¸oilo et al [19] in a confined environment such as survival shelters, and the possibility to simplify those signals according to their total impulse.…”

Prediction of blast loading in an internal environment using artificial neural networks

“…Generally, the accuracy of these methods is controlled by the coarseness of the element mesh forming the environment or the step size used in the calculation process. This is discussed further by Caçoilo et al (2018), who studied the propagation of blast waves inside a survival blast chamber using an LS-DYNA numerical model. Through comparing the numerical results to a physical experiment, the authors reported specific impulse errors below 19% when using a mesh size of 3.25 mm.…”

Semi-confined blast loading: experiments and simulations of internal detonations

“…Other simplified approaches exist [16,17], but to evaluate possible shadowing or amplification effects for which no test data are available, robust numerical models are crucial [18]. Naturally, numerical solutions are dependent on the discretisation [19]-finer discretisation gives, in general, more accurate solutions but adds to the computational time.…”