LS Dyna ile Serbest Hava Ortamındaki Patlama Yükünün Sayısal Simülasyonu için SPH, ALE, Birleştirilmiş ALE-LBE ve CONWEP Yöntemlerinin İncelenmesi

Öz

Yapıların patlama yükünün etkilerine tepkisini modellemek için farklı simülasyon yöntemleri kullanılabilir. Bazı simülasyon yöntemleri ampirik patlama yükleme ilkelerine dayalıyken, diğer yöntemler patlama sonrası şok dalgalarını ve bunların fiziksel etkilerini tahmin etmek için bir akışkan-yapı etkileşim algoritması kullanır. Bu çalışmada, deneysel bir çalışmanın sonuçlarına göre CONWEP, SPH, ALE ve birleştirilmiş MM-ALE ile LBE sayısal yöntemleri birbiriyle karşılaştırılmıştır. Her bir yöntem, çözüm süresi, yakınsama ve farklı patlayıcı türleri ve ortamları için kullanım açısından test sonuçlarıyla değerlendirilmiştir. Bu karşılaştırmaya göre ampirik yöntemlerin daha sınırlı çevre koşulları ve patlatma türleri için kullanılabileceği, ALE sayısal yöntemlerinin farklı çözüm setlerinde dahi çok hassas sonuçlar verebileceği ancak çözüm süresinin uzun olduğu sonucuna varılmıştır. SPH yönteminde ise hava ve patlama şokunun etkileşimi tam olarak modellenememektedir. Çalışmanın sonuçlarına göre, küresel serbest hava patlama yükü koşullarında hibrit yöntem, P1'de %7,44 ve P2'de %2,29 sapma ile tepe basıncı açısından test sonuçlarıyla uyumludur. Ancak hibrit yöntemde yansıyan basıncın etkileri tam olarak modellenemediğinden daha karmaşık geometrilerin olduğu durumlarda ALE yöntemi tercih edilmelidir.

Anahtar Kelimeler

• Serbest Hava Ortamında Patlama
• Numerik Simulasyon
• Patlama
• Küresel Patlama Yükü
• Yüksek Patlayıcılar

Investigation of Numerical Methods SPH, ALE, Coupled MM-ALE with LBE and CONWEP Empirical method for Simulation of the Spherical Free Air Blast Loading with Using LS Dyna

Abstract

Different simulation methods can be used to model the response of structures to the effects of blast loading. While some simulation methods are based on empirical blast loading principles, other methods use a fluid structure interaction algorithm to predict post-explosion shock waves and their physical effects. In this study, CONWEP, SPH, ALE, and coupled MM-ALE with LBE numerical methods were compared against each other according to results from an experimental study. Each method was compared with the test results in terms of solution time, convergence, and the use for different explosive types and environments. According to this comparison, it was concluded that empirical methods can be used for more limited environmental conditions and blast types, ALE numerical methods can give very sensitive results even in different solution sets but the solution time is long. Meanwhile in SPH method, the interaction of the air and blast shock cannot be fully modelled. According to the results of the study, the hybrid method is consistent with the test results in terms of peak pressure with a deviation of 7.44% at P1 and 2.29% at P2 under spherical free air blast loading conditions. However, since the effects of reflected pressure cannot be modelled exactly in the hybrid method, the ALE method should be preferred in cases with more complex geometries.

Keywords

• Free Air Blast
• Numerical Simulation
• Explosion
• Spherical Blast Load
• High Explosive

Kaynakça

1. Baker W. E., 1974. Explosions in air., University of Texas Press, Austin, TX, USA., AMCP 706-181, 1-2.
2. Boyd S.D., Acceleration of a plate subject to explosive blast loading-trial results, in, DTIC Document, Aeronautical and Maritime Research Laboratory, Melbourne, Victoria, Australia, 2, 2000.
3. Cranz C., Lehrbuch der Ballistik, Springer, Berlin, Germany, 178, 1926.
4. Erdik A., Uçar V., On evaluation and comparison of blast loading methods used in numerical simulations. Sakarya Üniversitesi Fen Bilimleri Enstitüsü Dergisi, 22(5), 1385-1391, 2018.
5. Fichera C., Peroni L., Scapin M., Numerical simulation of landmine explosions: comparison between different modelling approaches. In COUPLED V: proceedings of the V International Conference on Computational Methods for Cou-pled Problems in Science and Engineering: (pp. 708-719). CIMNE, 2013.
6. Flis L., Dobrociński S., Numerical Simulations of Blast Loads from Near-Field Ground Explosions in Air. Studia Geotechnica et Mechanica. 37. 11-17. 10.1515/sgem-2015-0040, 2015.
7. Friedlander F. G., ‘The diffraction of sound pulses. I. Diffraction by a semi-infinite plane’, Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 186(1006), 322–344, 1946.
8. Hallquist J. O., LS-DYNA Theory Manual, Livermore Software Technology Corporation, CA, USA, 17.1, 2006.

9. Han Y., Liu H., Finite Element Simulation of Medium-Range Blast Loading Using LS-DYNA. Shock and Vibration. 2015. 1-9. 10.1155/2015/631493, 2015.
10. Hopkinson B., British Ordnance Board Minutes, Report 13565, British Ordnance Office, London, UK, 11, 1915.
11. Hyde D. W., Conventional Weapons Program (CONWEP), U.S Army Waterways Experimental Station, Vicksburg, MS, USA, 18, 1991.
12. Karlos V., Solomon G., Calculation of Blast Loads for Application to Structural Components. 10.2788/61866, 2013.
13. Kingery C., Bulmash G., Air blast parameters from TNT spherical air burst and hemispherical burst, US Army Armament and Development Center, Ballistic Research Laboratory, Aberdeen Proving Ground, Maryland, 51, 1984.
14. Kingery C., Coulter G., Tnt Equivalency of Pentolite Hemispheres, ARBRLTR-02456, Aberdeen, Maryland, 1983.
15. Lee E. L., Hornig H. C., Kury J. W., Adiabatic expansion of high explosive detonation products, Technical Report TID 4500-UCRL 50422, Lawrence Radiation Laboratory, University of California, CA, USA, 2, 1968.
16. Luo H., Baum J. D., Löhner R., On the computation of multi-material flows using ALE formulation, Journal of Computational Physics 194(1), 304–328, 2004.
17. Messahel R., Soulie Y., SPH and ALE Formulations for Fluid Structure Coupling. CMES - Computer Modeling in Engineering and Sciences. 96, 2013.
18. Randers-Pehrson G., Bannister K., Air blast Loading Model for DYNA2D and DYNA3D, DTIC Document, 13, 1997.
19. Rebelo H. B., Cismasiu C., A Comparison between three air blast simulation techniques in LS-DYNA. In 11th European LS-DYNA Conference, 2017.
20. Rigby Sam., Blast wave clearing effects on finite-sized targets subjected to explosive loads, PhD Thesis, The Department of Civil and Structural Engineering at the University of Sheffield, Sheffield, 168, 2014.
21. Roache P., Verification and Validation in Computational Science and Engineering.Korkmaz K., Investigation and characterization of electrospark deposited chromium carbide-based coating on the steel. Surface and Coatings Technology 272(1), 1-7, 2015, 1998.
22. Schwer L., A Brief Introduction to Coupling Load Blast Enhanced with Multi-Material ALE: The best of Both Worlds for Air Blast Simulation, 9th International LS-DYNA Forum, Bamberg, Germany, J-I-2, 2010.
23. Schwer L., Jones-Wilkens-Lee (JWL) Equation of State with Afterburning, 14th International LS-DYNA User Conference, Constitutive Modeling, Detroit, USA, 1-29, 2016.
24. Slavik T. P., A Coupling of Empirical Explosive Blast Loads to ALE Air Domains in LS-DYNA, 7th European LS-DYNA Conference, Salzburg, Austria, 10, 2009.
25. Tabatabaei Z. S., Volz J. S., A comparison between three different blast methods in LS-DYNA: LBE, MM-ALE, Coupling of LBE and MM-ALE. In 12th International LS-DYNA Users Conference (pp. 1-10), 2012.
26. Trajkovski J., Kunc R., Perenda J., Prebil I., Minimum mesh design criteria for blast wave develop- ment and structural response – MMALE method. Latin American Journal of Solids and Structures. 11. 1999. 10.1590/S1679-78252014001100006, 2014.
27. UFC 3-340-02, Structures to Resist the Effects of Accidental Explosions, Department of the Army and Defense Special Weapons Agency, Washington, DC, USA, 2008.
28. Zakrisson B., Wikman B., Häggblad H., Numerical simulations of blast loads and structural deformation from near-field explosions in air, International Journal of Impact Engineering. Volume 38, Issue 7, 597-612, 2011.
29. Zakrisson B., Wikman B., Häggblad H.-Å., Numerical simulations of blast loads and structural deformation from near-field explosions in Air, International Journal of Impact Engineering, 38(7), pp. 597–612. Available at: https://doi.org/10.1016/j.ijimpeng.2011.02.005, 2011.