Papers by Keyword: Detonation Properties

Abstract: To explore effects of air humidity on properties of JO-9159 explosive, the amorphous model of six components was constructed by Materials Studio software, periodic molecular dynamics simulation was conducted at seven kinds of relative humidity ranging from 10% to 70% for (001), (010), (100) crystal planes of JO-9159 explosive in COMPASS force field and NVT ensemble. Mechanical properties, sensitivity and detonation properties of JO-9159 explosive were researched basing on equilibrium trajectory of model. The results show that with the increasing of relative humidity, the total adsorption energy increases. The adsorption capacity of JO-9159 explosive for H₂O is much stronger than O₂ and N₂; The breaking strength has a decreasing trend with the humidity increases and the stiffness and hardness of JO-9159 explosive are smaller at 30% and 40% relative humidity; At 30% relative humidity, the sensitivity of JO-9159 explosive is highest and detonation properties are weakest, while the detonation properties are strongest at 20% relative humidity.

Abstract: The heat of formation (HOF) for a caged owurtzitane analogue compound of 4,10-dinitro-2,6,8,12-tetraoxa-4,10-diaza-tetracyclododecane (TEX) was obtained by density functional theory B3LYP method with 6-31+G** basis set. The isodesmic reaction, instead of atomization reaction, makes good use of the available experimental data of HOFs and thus ensures the credibility of the result. The value of HOF of TEX is –448.37 kJ/mol. The predicted detonation velocity is about 8.2 km/s and detonation pressure is 31.44 GPa. The dissociation energy for the N-NO2 bond of TEX is 165.43 kJ/mol. There is large strain in TEX with strain energy of 62.47 kJ/mol. The nitro group interaction in TEX is small.

Abstract: One of the most important tasks of thermochemical codes for the calculation of detonation properties is the accurate description of the state of gaseous products within a rather wide range of pressures and temperatures – from several hundreds of kbar and several thousands of K to atmospheric pressure and temperature. Due to its simplicity and convenience, the Becker-Kistiakowski-Wilson (BKW) equation of state is used in many practical applications in the explosives field, despite its lack of rigorous theoretical background. The BKW EOS gives good agreement between calculated and experimentally obtained detonation parameters for many standard high explosives having densities in the range 1.2 – 2 g/cm3. However, it fails to predict accurately detonation properties at lower densities. To overcome this problem, we introduced the concept of density dependent molecular covolumes in the BKW EOS instead of invariant. The applicability of the approach is verified by comparing experimental and calculated values of detonation parameters for a series of explosives having different formulations and densities. It was found that by applying this approach the accuracy of the calculations for lower densities can be significantly improved.