Atıl ERDİK, Vahdet UÇAR

On evaluation and comparison of blast loading methods used in numerical simulations

Dynamic behavior of structures exposed to blast loading have been widely investigated to assess the integrity of structures and to examine structural factors influencing survivability of occupants. Numerical simulation techniques are efficient design tools to estimate the response of structures under blast loading. This study investigates numerical simulation of blast loading by using LS-DYNA explicit solver. In LS-DYNA, blast simulations are carried out through the following methods: CONWEP, Arbitrary Lagrangian Eulerian (ALE), and hybrid CONWEP-ALE. The aim of this study is to evaluate three blast loading approaches in order to get better understanding on the requirements of computational effort, accuracy of blast loading scheme, and influence of element size. Therefore, an experimental testing of a flat plate subjected to blast loading is modeled using these three blast loading methods in LS-DYNA. Mesh resolution study of ALE formulation is also carried out to determine the effect of element mesh size on predicting blast loading effects that is converted through fluid structure interaction algorithm from Eulerian to Lagrangian type of elements. It is drawn a comparison between peak pressures calculated in simulations and maximum dynamic deformation measured in the field test. Finally, the discussion and conclusion are provided.

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P. D. Smith and J. G. Hetherington, Blast and ballistic loading of structures. 2003, Eastbourne, Great Britain: Antony Rowe Ltd.

U.S. Army Corps of Engineers, N.F.E.C., Air Force Civil Engineering Support Agency, Design and analysis of hardened structures to conventional weapons effects, in Supersedes TM 5-855-1/NAVFAC P- 1080/AFJAM32/DSWA DAHSCWEMAN-97 August 1998. 2002, Department of the Army: US Army Corps of Engineers and Defense Special Weapons Agency, Washington, DC.

G. Randers-Pehrson and K. A. Bannister, Airblast Loading Model for DYNA2D and DYNA3D, in ARL-TR-1310. 1997, US Army Research Laboratory: Aberdeen Proving Ground.

J. O. Hallquist, LS-DYNA keyword user’s manual. 2007, Livermore Software Technology Corporation: California, U.S.A.

G. Sławiński, M. Świerczewski, and P. Malesa, Modelling and numerical analysis of explosion underneath the vehicle. Journal of KONES Powertrain and Transport, 2017. 24(4).

J. Donea, S. Giuliani, and J.-P. Halleux, An arbitrary Lagrangian-Eulerian finite element method for transient dynamic fluid-structure interactions. Computer methods in applied mechanics and engineering, 1982. 33(1-3): p. 689-723.

S. G. Lee, et al., Shock Response Analysis of Blast Hardened Bulkhead in Partial Chamber Model under Internal Blast. Procedia Engineering, 2017. 173: p. 511-518.

T. P. Slavik, A Coupling of Empirical Explosive Blast Loads to ALE Air Domains in LS-DYNA. in 7th European LS-DYNA Conference. 2009. Salzburg, Austria: Livermore Software Technology Corporation.

S. H. Than, et al., Fluid-Structure Interaction involving Close-in Detonation Effects on Column using LBE MM-ALE Method, in 9th European LS-DYNA Users Conference. 2013, Dynamore: Manchester, UK.

Z. S. Tabatabaei, et al., Experimental and numerical analyses of long carbon fiber reinforced concrete panels exposed to blast loading. International Journal of Impact Engineering, 2013. 57: p. 70-80.

C. N. Kingery and G. Bulmash, Airblast parameters from TNT spherical air burst and hemispherical surface burst. 1984, Ballistic Research Laboratory, Aberdeen Proving Ground, Aberdeen, MD.

A. L. Kozak, et al., Validation of the ALE Methodology by Comparison with the Experimental Data Obtained from a Sloshing Tank, in 14th International LS-DYNA Users Conference. 2016: Detroit.

B. M. Dobratz, LLNL explosives handbook: properties of chemical explosives and explosives and explosive simulants. 1981, Lawrence Livermore National Laboratory: California, U.S.A.

J. O. Hallquist, LS-DYNA theory manual, in, Livermore Software Technology Corporation, 2006.

L. Schwer, H. Teng, and M. Souli, LS-DYNA Air Blast Techniques: Comparisons with Experiments for Close-in Charges. 10th European LS-DYNA Conference 2015. Würzburg, Germany2015, 2015.