Model-based simulation of the synergistic effects of blast and fragmentation on a concrete wall using the MPM
Model-based simulation of the synergistic effects of blast and fragmentation on a concrete wall using the MPM
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DOI：
10.1016/j.ijimpeng.2005.05.004
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发表时间：
2006-12
影响因子：
5.1
通讯作者：
Wen Hu;Zhen Chen
中科院分区：
文献类型：
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作者：
Wen Hu;Zhen Chen
随着计算流体力学(CFD)向计算结构动力学(CSD)发展的物质点方法(MPM)的发展，本文采用基于模型的模拟方法来研究爆炸和破片对结构破坏的协同效应。从公开文献中可以发现，BLAST和碎片的协同效应通常通过CFD程序和CSD程序之间的接口通过组合的方法来模拟。因此，数值解对不同物理现象的不同时间步长和空间网格的选择非常敏感，特别是对于涉及结构破坏起始和演化的多物理现象。因此，如果需要客观的结果，在单个计算域内的耦合方法似乎是必要的。本文提出了一种利用MPM的数值方法，使得不同类型的梯度和散度算子可以在一个计算区域内离散，而不涉及固定的网格连通性。为了模拟冲击失效的演化，通过分叉分析识别了从连续失效模式到不连续失效模式的转变。通过一维和二维等温情况，包括套管炸弹的爆炸和破碎、冲击波通过破碎壳的扩展以及爆炸和破片对混凝土墙的撞击，验证了所提出的基于模型的模拟方法的潜力。数值研究中得到的初步结果有助于更好地理解抗冲击/抗爆炸结构设计中的协同效应。需要进行综合的实验、分析和计算工作，以进一步改进拟议的一般应用程序。
With the development of the material point method (MPM) that is an extension from computational fluid dynamics (CFD) to computational structural dynamics (CSD), a model-based simulation is performed in this paper to investigate the synergistic effects of blast and fragmentation on structural failure. As can be found from the open literature, the synergistic effects of blast and fragmentation have been usually simulated via a combined approach through an interface between CFD codes and CSD codes. As a consequence, numerical solutions are very sensitive to the choices of different time steps and spatial meshes for different physical phenomena, especially for the multi-physics involved in the initiation and evolution of structural failure. Hence, a coupled approach within a single computational domain seems to be necessary if objective results are needed. In this paper, a numerical procedure is proposed with the use of the MPM, so that different kinds of gradient and divergence operators could be discretized in a single computational domain without involving fixed mesh connectivity. To simulate the evolution of impact failure, the transition from continuous to discontinuous failure modes is identified via the bifurcation analysis. The potential of the proposed model-based simulation procedure is demonstrated through 1D and 2D isothermal cases including cased bomb expansion and fragmentation, blast wave expansion through a broken case, and blast and fragment impact on a concrete wall. The preliminary results obtained in this numerical study provide a better understanding of the synergistic effects on impact/blast-resistant structural design. An integrated experimental, analytical and computational effort is required to further improve the proposed procedure for general applications.