Hang, GY; Yu, WL; Wang, T; Wang, JT; Miao, S
To research the effect of adulteration crystal defect on the properties of HMX/ nitroguanidine (NQ) cocrystal explosive, the perfect model and HMX/ NQ cocrystal explosive model with adulteration defect were established, respectively. The stability, sensitivity, detonation performance and mechanical properties of various models were predicted by molecular dynamics method. The binding energy, trigger bond length distribution, interaction energy of the N-N trigger bond, cohesive energy density, detonation parameters and mechanical properties of different models were obtained and compared with that of the perfect model. The results show that compared with the perfect crystal, the decrease range of binding energy of defective crystal is 1.28%-11.05%, which indicates that the intermolecular interaction energy decreases and the stability of explosive decreases. The increase range of trigger bond length of defective crystal is 0.46%-5.29%, while the decrease range of interaction energy of the N-N trigger bond is 0.63%-17.24% and the decrease range of cohesive energy density is 0.83%-10.85%, indicating that the sensitivity of explosive increases and the safety decreases. The decrease range of density, detonation velocity and detonation pressure of defective crystal is 0.89%-7.06%, 0.68%-5.41%, 1.85%-14.18%, respectively, meaning that the power and energy density decrease. Owing to the influence of crystal defect, the decrease range of tensile modulus, bulk modulus and shear modulus is 0.106-4.368GPa, 0.086-2.573GPa and 0.082-1.835GPa, respectively, the increase range of Cauchy pressure is 0.108-1.787GPa, indicating that the rigidity and hardness decrease, while the ductility increases. Therefore, crystal defect will have a negative effect on stability, sensitivity and detonation performance of HMX/NQ cocrystal explosive. © 2019, Editorial Board of Journal of Explosives & Propellants. All right reserved.