Research On The Method Of Impact Sensitivity Prediction Methods Of Energetic Materials Based On Molecules And Crystals

Safety is one of the most important characteristics of energetic materials?EMs?.It is often scaled by sensitivity.Acceptable sensitivity guarantees the safe application of EMs.However,as sensitivity is related to the multi-level structure and physicochemical properties of EMs,stimulus modes and environmental conditions,sensitivity is subject to serious uncertainty,which is the root cause of poor predictability of energetic materials.Based on this,based on the perfect crystal phase structure of energetic compounds,this paper carried out quantum chemistry,molecular dynamics?MD?and statistical analysis studies,proposed a new model for predicting impact sensitivity,and established bridge experiments and MD to evaluate energetic compounds thermal stability method,and preliminary proposed a classification method of impact sensitivity combined of theoretical calculation and experimental test.The paper not only expanded the research method of impact sensitivity,but aslo proposed a new sensitivity prediction method,which will help the molecular design of energetic compounds and recognize the sensitivity mechanism of EMs.The main research contents and results of this article are as follows:1)Using the method of density functional theory,structural optimization calculations and energy calculations were performed for twenty CHNO energetic molecules with high diversities in component,structure and impact sensitivity.Based on the"hot spot"theory,a self-ignition propagation coefficient?SIPC,k?was proposed to reflect the self-sustaining ignition ability of EMs,k and other impact sensitivity correlation indexes were correlated with impact sensitivity(H₅₀)respectively.The results showed that the correlation between k and H₅₀ is better than other indicators.The reliability and universality of the SIPC model were further verified by 148 energetic molecules with high diversity.2)The MD method was used to simulate the thermal decomposition of PETN,?-HMX and TATB at different programmed heating rates,and the important temperature points in the decomposition process were analyzed.The results showed that the higher the heating rate,the higher the pyrolysis temperature,which is consistent with the trend of experimental DSC.In order to avoid the magnitude difference in the heating rate between the MD simulation and the experimental DSC,the correlation erro r between the two is directly used.Matlab fitting was used to obtain the thermal decomposition temperature under extreme conditions?heating rate tends to zero?in combination with extrapolation.It was found that the experimental and simulated thermal decomposition temperature trends of the three substances were consistent,that is,PETN<?-HMX<TATB,thus a method for evaluating the thermal stability of energetic compounds was established by bridging experiments and MD.3)Based on the existing experimental test sensitivity values of EMs and the related factors of molecular and crystal levels,the sensitivity classification of EMs was explored and researched,which provides ideas for designing new EMs in consideration of multiple factors.