Molecular dynamics simulations have been performed to investigate well-known energetic material cyelotrimethylene trinitramine （RDX） crystal, 3-azidomethyl-3-methyloxetane （AMMO） and RDX/AMMO propellant. The resul...Molecular dynamics simulations have been performed to investigate well-known energetic material cyelotrimethylene trinitramine （RDX） crystal, 3-azidomethyl-3-methyloxetane （AMMO） and RDX/AMMO propellant. The results show that the binding energies on different crystalline surface of RDX changes in the order of （010）〉（100）〉 （001）. The interactions between RDX and AMMO have been analyzed by means of pair correlation functions. The mechanical properties of RDX/AMMO propellant, i.e. elastic coefficients, modulus, Cauchy pressure, and Poisson＇s ratio, etc., have been obtained. It is found that mechanical properties are effectively improved by adding some amounts of AMMO polymers, and the overall effect of AMMO on three crystalline surfaces of RDX changes in the order of （100）〉（010）〉（001）. The energetic properties of RDX/AMMO propellant have also been calculated and the results show that compared with the pure RDX crystal, the standard theoretical specific impulse of RDX/AMMO propellant decrease, but they are still superior to those of double base propellant.展开更多
Within the constraints of density functional theory(UB3LYP/6-311++G(d,p)),RDX/Al and RDX/2Al composites are investigated,considering various multiplicity states(singlet and triplet states).Depending on the localizatio...Within the constraints of density functional theory(UB3LYP/6-311++G(d,p)),RDX/Al and RDX/2Al composites are investigated,considering various multiplicity states(singlet and triplet states).Depending on the localization of Al atom(s)in space and multiplicity of the composite systems,the structure of RDX undergoes various degrees of perturbations.It has been shown that the presence of Al atoms affects the bond lengths,electron population as well as the HOMO and LUMO energies and the inter frontier molecular orbital energy gap of RDX.All these perturbations are thought to affect ballistic properties of the explosive molecule RDX.展开更多
In this paper,a primary model is established for MD(molecular dynamics) simulation for the PBXs(polymer-bonded explosives) with RDX(cyclotrimethylene trinitramine) as base explosive and PS as polymer binder.A series o...In this paper,a primary model is established for MD(molecular dynamics) simulation for the PBXs(polymer-bonded explosives) with RDX(cyclotrimethylene trinitramine) as base explosive and PS as polymer binder.A series of results from the MD simulation are compared between two PBX models,which are represented by PBX1 and PBX2,respectively,including one PS molecular chain having 46 repeating units and two PS molecular chains with each having 23 repeating units.It has been found that their structural,interaction energy and mechanical properties are basically consistent between the two models.A systematic MD study for the PBX2 is performed under NPT conditions at five different temperatures,i.e.,195 K,245 K,295 K,345 K,and 395 K.We have found that with the temperature increase,the maximum bond length(L max) of RDX N N trigger bond increases,and the interaction energy(E N-N) between two N atoms of the N-N trigger bond and the cohesive energy density(CED) decrease.These phenomena agree with the experimental fact that the PBX becomes more sensitive as the temperature increases.Therefore,we propose to use the maximum bond length L max of the trigger bond of the easily decomposed and exploded component and the interaction energy E N-N of the two relevant atoms as theoretical criteria to judge or predict the relative degree of heat and impact sensitivity for the energetic composites such as PBXs and solid propellants.展开更多
文摘Molecular dynamics simulations have been performed to investigate well-known energetic material cyelotrimethylene trinitramine （RDX） crystal, 3-azidomethyl-3-methyloxetane （AMMO） and RDX/AMMO propellant. The results show that the binding energies on different crystalline surface of RDX changes in the order of （010）〉（100）〉 （001）. The interactions between RDX and AMMO have been analyzed by means of pair correlation functions. The mechanical properties of RDX/AMMO propellant, i.e. elastic coefficients, modulus, Cauchy pressure, and Poisson＇s ratio, etc., have been obtained. It is found that mechanical properties are effectively improved by adding some amounts of AMMO polymers, and the overall effect of AMMO on three crystalline surfaces of RDX changes in the order of （100）〉（010）〉（001）. The energetic properties of RDX/AMMO propellant have also been calculated and the results show that compared with the pure RDX crystal, the standard theoretical specific impulse of RDX/AMMO propellant decrease, but they are still superior to those of double base propellant.
文摘Within the constraints of density functional theory(UB3LYP/6-311++G(d,p)),RDX/Al and RDX/2Al composites are investigated,considering various multiplicity states(singlet and triplet states).Depending on the localization of Al atom(s)in space and multiplicity of the composite systems,the structure of RDX undergoes various degrees of perturbations.It has been shown that the presence of Al atoms affects the bond lengths,electron population as well as the HOMO and LUMO energies and the inter frontier molecular orbital energy gap of RDX.All these perturbations are thought to affect ballistic properties of the explosive molecule RDX.
基金supported by the National Key Laboratory of Shock Wave and Detonation Physics,Institute of Fluid Physics,China Academy of Engineering Physics(076100-1197F)the Defence Industrial Technology Development Program(B1520110002)the State Key Laboratory of Explosion Science and Technology,Beijing Institute of Technology(KFJJ09-5)
文摘In this paper,a primary model is established for MD(molecular dynamics) simulation for the PBXs(polymer-bonded explosives) with RDX(cyclotrimethylene trinitramine) as base explosive and PS as polymer binder.A series of results from the MD simulation are compared between two PBX models,which are represented by PBX1 and PBX2,respectively,including one PS molecular chain having 46 repeating units and two PS molecular chains with each having 23 repeating units.It has been found that their structural,interaction energy and mechanical properties are basically consistent between the two models.A systematic MD study for the PBX2 is performed under NPT conditions at five different temperatures,i.e.,195 K,245 K,295 K,345 K,and 395 K.We have found that with the temperature increase,the maximum bond length(L max) of RDX N N trigger bond increases,and the interaction energy(E N-N) between two N atoms of the N-N trigger bond and the cohesive energy density(CED) decrease.These phenomena agree with the experimental fact that the PBX becomes more sensitive as the temperature increases.Therefore,we propose to use the maximum bond length L max of the trigger bond of the easily decomposed and exploded component and the interaction energy E N-N of the two relevant atoms as theoretical criteria to judge or predict the relative degree of heat and impact sensitivity for the energetic composites such as PBXs and solid propellants.
