Modeling heterogeneous energetic materials at the mesoscale
Modeling heterogeneous energetic materials at the mesoscale
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DOI：
10.1016/s0040-6031(01)00794-8
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发表时间：
2002-02-25
影响因子：
3.5
通讯作者：
Baer, MR
中科院分区：
文献类型：
--
作者：
Baer, MR
通过对离散“晶体”集合的冲击进行冲击物理分析，研究了冲击多孔含能材料的固结、变形和反应的细观过程。这项工作为提高我们对中尺度过程的理解奠定了基础，以推进含能材料性能预测和安全评估的连续体水平模型。高分辨率的三维数值模拟表明，材料接触点处发生快速变形，产生在多个颗粒直径上持续存在的大幅应力波动。当材料流入间隙区域时，由于内部边界附近的冲击聚焦和塑性作用，能量的局部化会产生“热点”。数值模拟表明“热点”受到多种晶体相互作用的强烈影响。化学反应过程还会引起与颗粒分布效应相关的多种波结构。这项研究为异质含能材料的微机械行为提供了新的见解，强烈表明与冲击异质含能材料中的引发和持续反应相关的重要统计信息可能嵌入在与连续介质水平模型中传统使用的单一冲击跳跃描述明显不同的波动状态中。 (C) 2002 Elsevier Science B.V. 保留所有权利。
The mesoscopic processes of consolidation, deformation, and reaction of shocked porous energetic materials are studied using shock physics analysis of impact on an ensemble of discrete "crystals". This work provides a foundation for improving our understanding of the processes at the mesoscale to advance continuum-level models for energetic material performance prediction and safety assessment. Highly resolved, three-dimensional numerical simulations indicate that rapid deformation occurs at material contact points, producing large amplitude fluctuations of stress that persist over several particle diameters. Localization of energy produces "hot-spots" due to shock focusing and plastic work near internal boundaries as material flows into interstitial regions. Numerical simulations indicate that "hot-spots" are strongly influenced by multiple crystal interactions. Chemical reaction processes also induce multiple wave structures associated with particle distribution effects. This study provides new insights into the micromechanical behavior of heterogeneous energetic materials, strongly suggesting that important statistical information associated with initiation and sustained reaction in shocked heterogeneous energetic materials may be embedded in fluctuating states that are distinctly different than the single shock jump descriptions traditionally used in continuum level models. (C) 2002 Elsevier Science B.V. All rights reserved.