基于分子动力学的DNAN基熔铸炸药结合能和热分解反应性能研究

采用Compass力场对DNAN基熔铸炸药的结合能、溶度参数进行分子动力学模拟。计算结果表明:DNAN/RDX混合体系的溶度参数大于DNAN/HMX混合体系的溶度参数;当RDX团簇和HMX团簇的直径均大于15×10^-10 m时，DNAN/RDX混合体系的结合能远大于DNAN/HMX混合体系的结合能。基于ReaxFF-lg力场的分子动力学计算方法，对目标温度为2 000~3 500 K时DNAN/RDX混合炸药的热分解反应进行研究。结果表明:DNAN分子和RDX分子在高温下的初始分解反应路径均会受到影响;除了两种组分的硝基官能团发生脱落形成硝基官能团的初始反应路径不会受到影响之外，DNAN分子生成CH₂O碎片、RDX分子生成HONO和C₃H₃N₃碎片的反应路径均会受到抑制。

Binding Energy and Thermal Decomposition Reaction Properties of DNAN-Based Melt-Cast Explosive Based on Molecular Dynamics

Molecular dynamics simulation of the binding energy and solubility parameters of DNAN-based melt-cast explosive was carried out by Compass force field. The calculated results show that the solubility parameters of DNAN/RDX mixed system are greater than those of DNAN/HMX mixed system. When the diameter of RDX cluster and HMX cluster are greater than 15×10^-10 m, binding energy of DNAN/RDX mixed system is much larger than that of DNAN/HMX mixed system. Based on the molecular dynamic calculation method of ReaxFF-lg field, thermal decomposition reaction of DNAN/RDX mixed explosive at the target temperature of 2 000-3 500 K was studied. Results show that the initial decomposition reaction path of both DNAN and RDX molecules would be affected by high temperature. In addition to the initial reaction path to form the nitro functional groups by shedding off the two components, the reaction path to form CH₂O fragments from DNAN and to form HONO and C₃H₃N₃ fragments from RDX molecules would be inhibited.