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

Abstract

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.

Keywords

• 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

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