To address the theoretical deviations caused by the CJ(Chapman-Jouguet)hypothesis in the calculation of detonation parameters, the LADM(Least Action Detonation Model)based on the principle of least action was adopted. In this model, the entropy principle is used to determine the endpoint of the detonation process, while the Hamilton principle is applied to describe the reaction zone of the detonation, thereby replacing the traditional CJ hypothesis. The model was used to calculate detonation velocity parameters for 29 types of typical gaseous, liquid, and solid elemental explosives, including metallic hydrogen and all-nitrogen compounds, as well as mixed explosives. The detonation heat values were measured with calorimetric bomb, and the adiabatic index closely matched theoretical values. The results show good agreement between calculated and experimental data, demonstrating strong universality of the method. This indicates that the proposed approach can effectively calculate detonation parameters of novel explosives, offering solid theoretical guidance and promising application prospects.

A novel heat-resistant explosive, 2,6-bis(tetrazolylamino)-3,5-dinitro-4-pyridone-1,1'-dipotassium salt, was synthesized from 4-amino-2,6-dichloropyridine and 5-amino-1H-tetrazole by a three-step reaction of nitration, condensation, and oxidation in an overall yield of 41%. The target compound was characterized using nuclear magnetic resonance spectroscopy(¹H and¹³C), Fourier transform infrared spectroscopy and elemental analysis, and its structure was determined by single crystal X-ray diffraction. The thermal stability was investigated by differential scanning calorimetry(DSC)and thermogravimetry(TG)analyzer, the mechanical sensitivity was determined by BAM method, and the detonation properties were predicted by EXPLO5 software. The results show that the crystal of 4·5H₂O belongs to triclinic crystal system, Pī space group, with a crystal density of 1.782g/cm³(296K). The anionic ligand structure is nearly planar and exhibits face-to-face π-π stacking, which further forms a three-dimensional coordination polymer structure by coordinating with K⁺. Compound 4 has a measured density of 2.10g/cm³, a thermal decomposition temperature of 308.5℃, a detonation velocity of 7884m/s, a detonation pressure of 25.02GPa, an impact sensitivity of 20J, and a friction sensitivity of above 360N, indicating good heat resistance, low sensitivity and high energy.

In order to make up for the small production capacity, poor stability of the production process and low production efficiency of m-dinitrobenzene(m-DNB)in the traditional kettle production process, m-DNB was synthesized based on a microchannel reactor using nitrobenzene(NB)as the raw material, ethylene dichloride as the solvent, and a mixture of fuming nitric and fuming sulfuric acids as the nitrifying agent. The effects of the molar ratio of mixed acids, molar ratio of nitric acid to NB, reaction temperature, and total flow rate of the material on the nitrification reaction were investigated, where the reaction kinetics was also studied. The results show that the optimal conditions for the reaction are 60mL/min for the total flow rate of the material, 1:4 for the molar ratio of nitric acid to sulfuric acid, 1:2 for the molar ratio of NB to nitric acid, and 40℃ for the reaction temperature, under which the yield of m-DNB is as high as 93.60%. The activation energy of the NB nitration reaction is 63.930kJ/mol, and the finger-forward factor is 1.115×10⁹ L/(mol·s). It indicates that the microchannel reactor has the advantages of high heat transfer and mass transfer efficiency, accurate control of the reaction process, and high safety.

In order to obtain the application properties of HMX containing RDX impurities, HMX/RDX composites doped with different RDX contents were prepared by solvent-non-solvent method using N,N-dimethylformamide and dimethyl sulfoxide as the mixed solvent. The morphology, structure, and thermal properties of the prepared HMX/RDX composites were characterized by SEM, XRD, FT-IR and DSC-TG, and their mechanical sensitivities were analyzed. The results show that the prepared RDX-doped HMX/RDX composites are of blocky and flat circular particles, where the particle sizes mainly distribute in the range of 0.5—3μm. The particle size of the composites decreases with the increase of the RDX-doped content, and the doping of RDX has no effect on the crystalline morphology and phase of HMX. The RDX-doped HMX/RDX composite only has one decomposition exothermic peak, which means the doping is uniform. Compared with pure HMX, the exothermic decomposition peak temperatures and apparent thermal decomposition enthalpies of RDX-doped composites decrease slightly with the increase of RDX content(less than 30%), while their mechanical sensitivity is decreased and their safety properties are improved. They can effectively replace pure HMX in some applications.

In order to obtain the damage characteristics of the double-layer shell structure under the underwater explosion of the shelled charge, the damage test of the double-layer shell structure under the underwater explosion was carried out with a small explosive tank device, and the influence of the hollow medium at the back cavity of the inner plate, the filling medium between the inner and outer plates, the explosion position and distance and other factors on the damage characteristics of the double-layer shell were analyzed, and the damage mode of the double-layer shell structure under the underwater explosion of the shelled charge was obtained. The results show that under the contact explosion of the underwater shell charge, there are three kinds of damage modes: the overall plastic deformation of the double-layer shell, the tearing of the inner and outer plates in the shape of “mouth”, “grid” and “cross”, and the local bending or fracture deformation of the inner and outer plates and ribs. Under the same underwater contact explosion conditions, when the explosion position is at the intersection of the transverse and longitudinal ribs of the double-layer shell, the damage range caused to the inner and outer plates is larger, and the filling of the water medium between the double-layer shells greatly reduces the impact effect on the inner shell and improves the impact resistance of the inner plate of the double-layer shell.

To investigate the effects of different machine oil-diesel ratios on the explosive properties of site-mixed emulsified explosives, the viscosity and particle size distribution of emulsion matrices with varying oil-diesel ratios by using digital viscometry, laser particle size analysis, and optical microscopy were examined, the internal phase structure of explosive samples was observed. The density of matrices and explosive specimens were measured through PVC tube simulations of borehole charging configurations. Detonation velocity and brisance were respectively determined by using a detonation velocity tester and lead cylinder compression method. The results reveal that as the oil-diesel ratio in explosive formulations increased from 0:5.5 to 5.5:0, the matrix viscosity rose from 1.5×10⁵mPa·s to 3.7×10⁵mPa·s. Concurrently, the sensitized bubble concentration increased while the bubble size decreased, demonstrating improved uniformity. The dispersed phase droplet size distribution narrowed significantly with distribution width decreased from 86.19μm to 6.33μm, the mean particle size reduced from 13.85μm to 2.78μm, and dispersion index declined from 6.23 to 2.27, indicating enhanced homogeneity. At 0.3% sensitizer content, the explosive density increased progressively from 0.95g/cm³ to 1.10g/cm³. Corresponding improvements in detonation performance were observed: the detonation velocity increased by 24.08% from 3155m/s to 3915m/s showing consistency with theoretical predictions from the B-W method, and the brisance increased by 34.48% from 9.05mm to 12.17mm.With increasing the sensitizer concentrations(0.3%,0.5%,0.7%), the bubble density increased and the explosive density reduced. Distinct performance trends emerged based on oil-diesel ratios: formulations with ratios ≤3:2.5 exhibited initial enhancement followed by decline in detonation parameters, while those with ratios ≥4:1.5 demonstrated progressive reduction in explosive performance characteristics.

In order to solve the problem of reducing the damage area caused by the axial energy waste of conventional fuel air explosive, numerical simulation researches on the multiphase cloud near-field growth process of fuel air explosive were carried out. The influence mechanism of axial non equal diameter degree on the near-field growth characteristics of cloud was revealed at multiple scales. By incorporating the baroclinic effect induced by axial non equal diameter and the annular shear fragmentation of the fuel, a multiphase cloud near-field growth model of axial non equal diameter structured fuel air explosive was constructed. Based on this model, the cloud size and radial growth rate were quantitatively calculated. The results show that the axial non equal diameter structured induces a baroclinic effect on the fuel. With the increase of axial non equal diameter, the radial growth rate of multiphase clouds in the near-field stage decreases, and the axial growth rate increases. The particle size distribution along the radial direction demonstrates a gradient decay from the center outward during the near-field stage. As the axial non equal diameter degree of the device intensifies, the axial velocity component of the fuel increases, whereas the radial component decreases, leading to a morphological transition of the multiphase cloud from a “lantern shape” to an “umbrella shape”. The central cavity size of the multiphase cloud was reduced in the axial non equal diameter structure, and the continuity of the internal distribution of the cloud was strengthened. A maximum deviation of less than 6.5% between the predicted cloud size and experimental data validates the reliability of the multiphase cloud near-field growth model.

An energetic binder based on hydroxyl-terminated polybutadiene(HTPB), doped with different ratios of nitrocellulose(NC)(10%, 20%, 30%, and 50%), was developed to study the effect of NC doping on the thermal decomposition behavior of a composite propellant(CP)comprising ammonium nitrate(AN)as an oxidizer and magnesium(Mg)as a fuel. Optimization of the propellant formulation was conducted using Chemical Equilibrium with Applications-National Aeronautics and Space Administration(CEA-NASA)software, which demonstrated an increase in specific impulse by 12.09s when the binder contained 50% NC. Fourier-transform infrared spectroscopy(FTIR)analysis confirmed the excellent compatibility between the components, and density measurements revealed an increase of 6.4% with a higher NC content. Morphological analysis using optical microscopy showed that NC doping improved the uniformity and compactness of the surface, reduced cavities, and achieved a more homogeneous particle distribution. Differential scanning calorimetry(DSC)analysis indicated a decrease in the decomposition temperature of the propellant as the NC content increased, while kinetic studies revealed a 48.68% reduction in the activation energy when 50% NC was incorporated into the binder. These findings suggest that the addition of NC enhances combustion efficiency and improves overall propellant performance. This study highlights the potential of the new HTPB-NC energetic binder as a promising approach for advancing solid propellant technology.

To evaluate the anti-high overload performance of HTPB propellant over a wide temperature range, based on one-dimensional elastic stress wave propagation and loading theory, the test system for high overload loading of propellant charge was developed, the theoretical design of overload amplitude and pulse width of propellant charge strip sample under the single pulse loading was realized. In addition, the waveform shaping technology was combined to achieve accurate control of high overload stress wave, and the high and low temperature control systems were coupled to realize the wide temperature range axial high overload test condition of propellant. A series of high-overload experiments with different loading pulse widths(100, 200, 300μs)of propellant samples at 12000g and 16000 g overload amplitude under high and low temperature(-50, -20, 0, 25 and 70℃)were investigated. Based on the genetic integral form viscoelastic constitutive model, the finite element analysis of the high overload test process was carried out. Combined with μCT test and finite element analysis, the variation of damage response characteristics of propellant samples with overload amplitude, pulse width, temperature under complex and high overload loading were studied. The results show that under high overload conditions, with the same overload amplitude and pulse width, the stress level increases as the temperature decreases; under the same overload amplitude and temperature conditions, the stress level increases as the pulse width increases. The stress distribution of the propellant samples at high and low temperatures show a relatively consistent pattern, with the maximum stress occurring near the end of the load climbing section and stress concentration at the bottom of the propellant grain. By taking the compressive strength varying with strain rate and temperature as the strength criterion and through the coupled analysis of the stress field, strain rate field and temperature, the structural integrity of the propellant column can be guaranteed under five different temperatures and three different pulse widths under 16000g overload. Meanwhile, the increase of temperature would inhibit the formation of damage characteristics, while the increase of pulse width under loading would promote the formation of damage characteristics.

In order to further reduce the glass transition temperature(T_g)of HTPB propellants and expand their operational temperature range, the molecular structures and T_g values of high cis HTPB, anionic polymerized HTPB and type I HTPB were analyzed and compared. Propellants based on different HTPB were prepared, and their curing reaction kinetics, mechanical properties, energy performance, combustion performance, and feasibility of ignition at ultra-low temperatures were investigated. The results show that the molecular structures of HTPB has a significant influence on its T_g. The T_g of hydroxyl-terminated polybutadiene with a cis-1,4 structure accounting for 74% to 76% is approximately -101℃. Compared with type I HTPB propellants, propellants based on high cis HTPB has a lower curing reaction rate and a lower T_g. By using nonyl oleate plasticizer and optimizing the plasticization ratio, the T_g of HTPB propellant can reach -96.2℃. Compared with the propellant containing anionic polymerized HTPB and type I free-radical-polymerized HTPB as a binder, high-cis HTPB-based propellants have a lower elongation under the condition of comparable tensile strength. Verified by the BSFΦ118 engine tests and BSFΦ165 engine tests, the burning rate and energy performance of the high-cis HTPB propellant are at the same level as those of the type I HTPB propellant. High-cis HTPB-based propellants passed the -70℃ BSFΦ118 engine test, preliminary demonstrating the feasibility of high-cis HTPB propellants in ultra-low-temperature environments.