CL-20/DNB共晶炸药晶体缺陷的理论计算

Theoretical Calculation on Crystal Defect of CL-20/DNB Cocrystal Explosive

为了研究晶体缺陷对CL-20/DNB共晶炸药的力学性能、稳定性、感度与爆轰性能的影响,建立了"完美"型及带有晶体缺陷(掺杂、空位与位错)的CL-20/DNB共晶炸药模型;采用分子动力学方法计算了不同模型的力学性能、结合能、引发键键长分布、键连双原子作用能、内聚能密度与爆轰参数。结果表明,与"完美"型晶体相比,缺陷晶体的拉伸模量、体积模量与剪切模量的值减小,而柯西压的值增大,表明体系的刚性减弱,塑性与延展性增强;缺陷晶体的结合能减小幅度为9.30%~17.21%,表明炸药中分子之间的相互作用力减弱,炸药的稳定性变差;缺陷晶体的引发键最大键长增大幅度为0.45%~4.76%,而键连双原子作用能减小幅度为5.10%~17.20%,内聚能密度减小幅度为2.45%~13.71%,表明其感度增大,安全性变差;缺陷晶体的密度与爆轰参数减小,其中空位缺陷对能量的影响最大。因此,晶体缺陷会对CL-20/DNB共晶炸药的稳定性、感度与能量特性产生不利影响。

To research the effect of crystal defect on the mechanical properties, stability, sensitivity and detonation performance of CL 20/DNB cocrystal explosive, the perfect model and defective （adulteration, vacancy and disloca tion） CL 20/DNB cocrystal model were established. The mechanical properties, binding energy, trigger bond length distribution, interaction energy of trigger bond, cohesive energy density and detonation parameters of different co crystal models were calculated by molecular dynamics method. The results show that compared with the perfect model, the tensile modulus, bulk modulus and shear modulus of defective crystals are decreased, while Cauchy pres sure is increased, indicating that the rigidity of defective models is decreased, while plastic property and ductility are increased. The binding energies of defective crystals are declined by 9. 30% -17.21%, indicating that the intermo lecular interaction energy is decreased and the stability is worsened. The maximum trigger bond length of defective crystal models is increased by 0.45 %-4.76 %, while the interaction energy of trigger bond is decreased by 5.10 % -17.20 % and cohesive energy density is decreased by 2.45 %- 18. 71%, indicating that the sensitivity is increased and the safety is worsened. The density and detonation parameters of defective crystals are decreased, and the va cancy defective has the greatest effect on the energy. Therefore, crystal defect has a negative effect on stability, sensitivity and energetic performance of CL 20/DNB cocrystal explosive.