Coupling Effect of Shock, Heat, and Defect on the Decay of Energetic Materials: A Case of Reactive Molecular Dynamics Simulations on 1,3,5-Trinitro-1,3,5-triazinane
Coupling Effect of Shock, Heat, and Defect on the Decay of Energetic Materials: A Case of Reactive Molecular Dynamics Simulations on 1,3,5-Trinitro-1,3,5-triazinane
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冲击、热和缺陷对含能材料衰变的耦合效应：1,3,5-三硝基-1,3,5-三嗪反应分子动力学模拟案例
DOI：
10.1021/acs.jpcc.8b09170
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发表时间：
2018-12-13
影响因子：
3.7
通讯作者：
Zhang, Chaoyang
中科院分区：
文献类型：
--
作者：
Deng, Chuan;Liu, Jian;Zhang, Chaoyang
多种类型的外部刺激通常同时加载到含能材料（EM）上，因此它们对其衰变具有耦合效应。同时，电磁场的结构对衰减有着本质的影响。因此，这些刺激和结构的耦合效应，应考虑在评估衰减和进一步的安全EM。然而，它仍然是难以澄清的原子/分子的衰变和安全机制的耦合效应的细节。在目前的工作中，我们进行反应分子动力学模拟结合多尺度冲击技术，以揭示一个充满活力的代表，1，3，S-三硝基-1，3，5-三嗪烷（RDX）的衰变机制的冲击预热位错耦合效应。也就是说，三个因素，包括冲击波速度，预热温度，刃位错作为变量的模拟。提高冲击波速度和预热温度以及晶体中存在刃型位错都促进了RDX的衰变。预热提高了冲击波的灵敏度实验确定，和灵敏度的提高是由于由于预热的黑索今分子的势能升高。此外，有趣的是，两种不同的冲击-预热位错耦合可以对RDX衰变具有等效的影响，因为它们可以导致几乎相同的主要化学物种、温度、压力和势能的演变。这些研究结果将有助于我们深入了解外环境对外界刺激的反应机制，特别是在多因素耦合的情况下。
Multiple types of external stimuli are usually loaded on an energetic material (EM) simultaneously, and thus they have a coupled effect on its decay. Meanwhile, the structures of the EM essentially influence the decay. Thereby, the coupling effects of these stimuli and structures should be considered in assessing the decay and further the safety of EMs. Nevertheless, it is still difficult to clarify the atomistic/molecular details of the coupling effects on the decay and safety mechanisms. In the present work, we perform reactive molecular dynamics simulations in combination with the multiscale shock technique to reveal a shock preheating dislocation coupling effect on the decay mechanism of an energetic representative, 1,3,S-trinitro-1,3,5-triazinane (RDX). That is, three factors including shock velocity, preheating temperature, and edge dislocation are accounted as variables for the simulations. Increasing shock velocity and preheating temperature and presenting edge dislocation in crystal both promote the RDX decay. Preheating enhances the shock sensitivity as ascertained experimentally, and the sensitivity enhancement is caused by the elevated potential energy of the RDX molecules because of preheating. Moreover, interestingly, two different shock-preheating dislocation couplings can possess an equivalent effect on the RDX decay, as they can lead to almost same evolutions of major chemical species, temperature, pressure, and potential energy. All these findings are expected to deepen the insight into the response mechanisms for the EMs against external stimuli, particularly in the case of multiple factors coupled.