摘要
为从理论上寻求典型硝酸酯炸药太安(PETN)晶体的感度判据和力学性能,在NPT系综下,用COMPASS力场对PETN(4×3×4)超晶胞和沿其(100)晶面切割的两种模型,实施了5个温度(195,245,295,345,395K)的周期性分子动力学(MD)模拟。结果表明,随温度升高,它们的引发键O—NO2的最大键长(Lmax)递增,引发键连双原子作用能(EO-N)和内聚能密度(CED)递减,与感度随温度升高而增大的实验事实相一致。Lmax、EO-N和CED在一定条件下,确可用作高能物质热和撞击感度相对大小的理论判据。随温度升高,弹性系数与弹性模量递减,刚性减小,柔性递增,符合实验事实,表明,以切割分面模型进行MD模拟能获得较符合实际的确定结果。
To explore theoretically the sensitivity criterion and the mechanical properties of PETN explosive crystal, molecular dy- namics （MD） simulation periodic at 195, 245, 295, 345,395 K for （4 x3 x4） super cells and its cutting model along （100） crystalline surface was conducted by COMPASS force field in the NPT ensemble. The results show that as the temperature increa- ses, the maximum bond length （Lmax） of their O--NO2 trigger bond increases, the interaction energy （Eo_N ） between O atom and N atom of the O--NO2 trigger bond decreases and the cohesive energy density （CED） decreases. These results agree with the experimental fact that PETN becomes more sensitive as the temperature increases. The L Eo_N and CED can be used as the the- oretical criteria to predict the heat and impact sensitivity under certain conditions. With increasing the temperature, the elastic co- efficients and elastic modulus decrease, the stiffness of PETN crystal decreases and the flexibility increases, which agrees with the experimental fact, indicating that the MD simulation of PETN cutting model is able to yield more concrete quantitative results.
出处
《含能材料》
EI
CAS
CSCD
北大核心
2013年第5期563-569,共7页
Chinese Journal of Energetic Materials
基金
国家自然科学基金委员会与中国工程物理研究院联合基金(U1230120)
