摘要本文在COMPASS力场和NPT系综下,采用分子动力学(MD)方法,对奥克托金(HMX)晶体及HMX基高聚物粘结炸药(PBX)进行了模拟研究。
采用MD方法,分别对处于不同温度下的HMX晶体和HMX/石蜡PBX进行模拟,研究温度对HMX晶体和HMX/石蜡PBX各项性能的影响。结果表明随着温度的升高,体系的刚性、强度减弱,内聚能密度(CED)和N-N双原子作用能(EN-N)递减,引发键最大键长(Lmax)递增。CED、EN-N和Lmax在一定条件下可以作为高能晶体热和撞击感度相对大小的判别依据。同时我们也发现石蜡的加入可以导致体系的工程模量减小,表明刚性减弱,柔性增大,力学性能有所改善;体系内聚能密度降低,引发键最大键长增大,EN-N降低;石蜡的致钝作用不是电子结构因素所造成的。
氢化端羟基聚异戊二烯(HHTPI)、端羟基聚丁二烯(HTPB)和端羟基聚醚(HTPE)是三种常用的粘结剂。在同一温度下对三种HMX/端羟基聚合物PBXs进行MD模拟研究,发现Lmax排序为:HMX/HHTPI>HMX/HTPE>HMX/HTPB;EN-N的排序则相反;结合能大小的排序为HMX/HTPE>HMX/HTPB >HMX/HHTPI。这些规律的发现为粘结剂的配方设计提供了依据和指导。63844
毕业论文关键词:奥克托金(HMX);高聚物粘结炸药(PBX);分子动力学(MD)模拟;感度;粘结剂
毕业设计说明书(论文)外文摘要
Title Simulation study on the binary system of HMX and polymer
Abstract Molecular dynamics (MD) simulation was employed for octahydro-1,3,5,7- tetranitro-1,3,5,7-tetrazocane (HMX) crystal and HMX-based polymer bonded explosives (PBX) in NPT ensemble with COMPASS force field.
The influence of temperature on various properties was explored in different temperatures. The results show that with the rising of temperature, the stiffness and strength of the systems decrease, the maximum bond length of N-N trigger bond (Lmax) increases, and the cohesive energy density (CED) as well the interaction energy between two N atoms of the N-N trigger bond (EN-N) decrease. We propose to use CED、EN-N and Lmax as theoretical criteria to judge or predict the relative degree of heat and impact sensitivity for high-energy crystal. The results also show that with mixture of paraffins, the mechanical properties of PBX are improved, its CED and EN-N decrease, but Lmax increases. The desensitization of HMX/paraffins PBX are not caused by the electronic structures.
Hydrogenated hydroxyl-terminated polyisoprene (HHTPI), hydroxyl- terminated polybutadiene (HTPB) and hydroxy-terminated polyether (HTPE) are three frequently-used binding materials. The three HMX/hydroxyl- terminated polymer PBXs were investigated by MD simulation. The results show that the order of Lmax is HMX/HHTPI>HMX/HTPE>HMX/HTPB, while the order of EN-N is in reverse, and HMX/HTPE>HMX/HTPB>HMX/HHTPI is the rank of binding energy. These rules can provide reference for and guidance to the PBXs formulations.
Keywords:Octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX);Polymer bonded explosives (PBX);Molecular dynamics (MD) simulation;Sensitivity;Binding materials
1 绪论 1
1.1 课题背景及研究意义 1
1.2 HMX概述 1
1.2.1 HMX的结构 2
1.2.2 HMX基高聚物粘结炸药 2
1.3 研究方法 4
1.3.1 计算机模拟方法概述 4
1.3.2 分子动力学模拟及其基本原理 5
1.3.3 分子动力学模拟在含能材料领域的应用