Detonation Tests Research Articles

Effect of AP distribution on energy release characteristics and functional force of HMX/AP/Al explosives

AbstractIn order to understand the reaction kinetics of HMX/AP/Al ternary system, the different distribution of AP in HMX/AP/Al explosives was realized by two different preparation techniques. Detonation test results show that the detonation velocity, explosion heat and detonation pressure of HAP samples are higher than those of HAl samples, but the extent of improvement is not high, not more than 5 %. The results of scanning electron microscopy showed that AP in HAP samples was distributed on the surface of HMX crystal. AP were dispersed around HMX crystals in HAl samples. The experimental results of explosive fireball performance show that the fireball expansion speed of HAP samples is better than that of HAl samples, demonstrating a good fireball effect. Underwater test results show that the shock wave peak pressure and bubble pulsation period of HAP samples increase by 3.06 % and 7.95 % respectively, and shock wave energy and bubble energy increase by 9.8 % and 25.42 % compared with bubble energy. The experimental results show that HAP samples are superior to HAl samples in accelerating ability of Al flies. The dispersion of AP on the HMX crystal surface promotes the energy release of HMX/AP/Al explosives more.

Effect of oxygen rich environment on detonation characteristics of pulse detonation engine

The detonation tests of propane/air pulse detonation engine at normal temperature were carried out in this paper. The effects of chemical ratios on the detonation performance of propane/air pulse detonation engine in oxygen-rich environment were studied. The propagation modes and characteristics of detonation waves and the detonation characteristics of the engine under different conditions were analyzed. Detonation tests were conducted on propane/air mixtures with oxygen mass fraction of 20%, 25%, 30% and 35% respectively. The results showed that: In the detonation experiment of the propane/air mixture with oxygen content of 20%, 25% and 30%, the flame wave propagation velocity in the detonation tube is low, which fails to form a stable detonation wave. The detonation effect of the fuel mixture with oxygen content of 20% is the worst, and the propagation velocity of flame wave is 384.00 m/s. In the experiment of propane/air mixture with oxygen content of 35%, the detonation velocity and pressure obtained by pressure signal analysis are both greater than the theoretical CJ detonation velocity, and the detonation state is successfully reached.

Assessment of modeling methods for predicting load resulting from hydrogen-air detonation

As hydrogen becomes an increasingly vital component in the transition toward a sustainable energy system, its flammable and detonable properties necessitate a comprehensive understanding of its explosive characteristics. This study evaluated the accuracy and computational efficiency of an innovative numerical approach that integrates CESE compressible CFD solver, chemistry reaction model, and structural FEM solver within LS-DYNA to predict hydrogen detonation loads. Comparisons were made with the commonly used energy equivalent methods, i.e., the TNT equivalent method, and the high-pressure volume method, which utilizes multi-material ALE techniques. Hydrogen detonation test results from open-air space, open-air space with a blast wall, and semi-confined space were compared against numerical simulations. The results revealed that, for scaled distance exceeding 0.79 m/kg1/3, all three methods accurately predicted the peak overpressure. The TNT equivalent method exhibited an unexpectedly high energy efficiency factor exceeding 0.51, significantly surpassing the recommended range of 0.01–0.1 for typical vapor cloud accidents. The CESE-chemistry coupling method exceled in capturing overpressure duration and structural response due to its consideration of chemical kinetics. As the scaled distance reduced to 0.37 m/kg1/3, the CESE-chemistry coupling method maintained its proficiency in modelling pressure waves, while the TNT equivalent method overestimated peak pressure by 494%. Conversely, the high-pressure volume method underestimated the peak pressures within or near the H2-air cloud. Nevertheless, the CESE-chemistry coupling method required significantly higher computational costs, with 15–20 times more computational time compared to the other two methods, and 60–70% of the total computation time was spent solving chemical kinetics. It is concluded from the current study that for scenarios involving close scaled distances (less than 0.37 m/kg1/3) or where the structure locates inside or near the gas cloud, the CESE-chemistry coupling method may be preferred despite its higher computational demands. Conversely, for simulations prioritizing computational efficiency and larger scaled distances, the TNT equivalent method or high-pressure volume method is recommended. These findings offer guidelines for researchers and engineering professionals engaged in assessing and mitigating risks associated with hydrogen explosion accidents in the pursuit of safe and sustainable hydrogen utilization.

Sources of error in detonation calorimeters and error analysis for neat 2,4,6‐triamino‐1,3,5‐ trinitrobenzene (TATB)

AbstractA calorimeter for measuring heats of detonation at Lawrence Livermore National Laboratory is described. A calibration precision of 0.2 % at the 95 % confidence interval (CI) is reported. Sources of uncertainty are discussed, including nonequivalent sources, which are those arising from differences between calibration and experimental tests. The systematic error due to nonequivalent sources is bounded to 0.19–0.22 % of the measured heat for a standard detonation test where the confinement material is gold. The recommendation is to correct for the systematic error by adding 0.19 % to the reported value and adding 0.03 % to the uncertainty. It is demonstrated that the precision of a detonation test is variable with testing duration because a source of uncertainty resides in the thermodynamic correction factor k6, which accounts for the contribution to heat by stirring; the generated power is additive and therefore highly impacted by total test time. The relative proportion also varies with the magnitude of heat release and sample size, adding variance to the weight of the error arising from the correction factor. A full error analysis based on the described sources of uncertainty is developed. The methodology is applied to a test series on neat 2,4,6‐triamino‐1,3,5‐ trinitrobenzene (TATB), demonstrating an ultimate precision of 0.7 % (single test) for materials testing and a relative standard deviation of 1.8 %.

A multi-material diagnosis method based on high-energy proton radiography

Diagnosis of fluids is extremely significant at high temperatures and high pressures. As an advanced imaging technique, high-energy proton radiography has great potential for application to the diagnosis of high-density fluids. In high-energy proton radiography, an angular collimator can control the proton flux and thus enable material diagnosis and reconstruction of density. In this paper, we propose a multi-material diagnostic method using angular collimators. The method is verified by reconstructing the density distribution from the proton flux obtained via theoretical calculations and numerical simulations. We simulate a 20 GeV proton imaging system using the Geant4 software toolkit and obtain the characteristic parameters of single-material objects. We design several concentric spherical objects to verify the method. We discuss its application to detonation tests. The results show that this method can determine the material and boundary information about each component of a multi-material object. Thus, it can be used to diagnose a mixed material and reconstruct densities in a detonation.

Study on Axial Dispersion Characteristics of Double-Layer Prefabricated Fragments.

The axial distribution of initial velocity and direction angle of double-layer prefabricated fragments after an explosion were investigated via an explosion detonation test. A three-stage detonation driving model of double-layer prefabricated fragments was proposed. In the three-stage driving model, the acceleration process of double-layer prefabricated fragments is divided into three stages: "detonation wave acceleration stage", "metal-medium interaction stage" and "detonation products acceleration stage". The initial parameters of each layer of prefabricated fragments calculated by the three-stage detonation driving model of double-layer prefabricated fragments fit well with the test results. It was shown that the energy utilization rate of detonation products acting on the inner-layer and outer-layer fragments were 69% and 56%, respectively. The deceleration effect of sparse waves on the outer layer of fragments was weaker than that on the inner layer. The maximum initial velocity of fragments was located near the center of the warhead where the sparse waves intersected, located at around 0.66 times of the full length of warhead. This model can provide theoretical support and a design scheme for the initial parameter design of double-layer prefabricated fragment warheads.

Influence of Polyurea Packaging Material on Anti-explosion Performance of a Fuze

Polyurea coating has excellent anti-explosion performance. In order to solve the problem of sympathetic detonation of a fuze, a polyuria-coated packaging barrel is designed. ANSYS software is used to simulate the sympathetic detonation test to verify the anti-explosion performance of the packaging barrel. The shock wave and explosion products produced from explosion are obviously hindered. The packaging barrel and the fuze body are damaged but the booster of the fuze is not detonated. The maximum pressure of selected elements in booster is 13.0 GPa, which is less than the initiation pressure of TATB in the booster. The acceptor fuze is not sympathetically detonated. A sympathetic detonation test is carried out and the results are consistent with the simulation.

TNT equivalency method in confined space based on steel plate deformation

TNT equivalency has been a widely accepted concept in engineering. However, as a fuel-rich explosive, the afterburning effect of detonation products would be remarkable when TNT is detonated in a confined space. The additional energy release from the burning of detonation products makes the traditional TNT equivalency to be more complicated. In this paper, in order to reveal the influence of afterburning effect of detonation products under the condition of confined blast, a series of TNT detonation tests in a confined chamber filled with four different atmospheres, air, nitrogen, water mist, and combined nitrogen and water mist were performed. The temperature, pressure-time histories and deflection of blast loaded steel plate were recorded. It is found that the pressure, temperature and the dynamic response of the blast loaded plate in nitrogen and water mist atmosphere were significantly lower than those in the air conditions, due to different mechanisms of energy release and absorption. In addition, the relation between deflection of target plate and the released energy from explosive was established. Furthermore, the method of determining TNT equivalency in confined explosion considering the afterburning effect was proposed and was employed to determine the TNT equivalency of a cased charge. By comparing the present TNT equivalency method with the method based on quasi-static pressure, the potential application of the method has been illustrated.

Results and evaluation of US Navy shock trial environmental mitigation of marine mammals and sea turtles

A shock trial of a US Navy Destroyer, the USS Winston S. Churchill, was conducted offshore of northern Florida in May and June 2001. The shock trial consisted of three underwater detonation tests, spaced approximately one week apart. Environmental mitigation to minimise the impact of the shock trial on marine mammals and sea turtles was based on a Safety Range of 3.7km (2 n.miles) radius around the detonation site, and a Buffer Zone of an additional 1.85km (1 n.mile) radius beyond the Safety Range. Mitigation included site selection surveys, pre-detonation aerial, vessel and bio-acoustic monitoring, and post-detonation aerial and vessel monitoring. Six species of odontocete and two species of sea turtle were identified during mitigation monitoring, as well as several sightings that could not be identified by species. Site selection aerial surveys were implemented to select a test site with the lowest abundance of marine mammals and sea turtles. Nearly 300 animals were seen during site selection surveys. Pre-detonation aerial and vessel monitoring was implemented to sight any marine mammal and sea turtle within the Safety Range on designated test days, and track the animals until they could be verified to be outside the Safety Range. Approximately 1,200 marine mammals and 32 sea turtles were sighted during pre-detonation monitoring. Pre-detonation bio-acoustic monitoring was implemented to detect large cetaceans within the Safety Range and Buffer Zone; the only calls heard were from dolphins that could not be localised. Post-detonation monitoring was implemented to determine the effectiveness of mitigation procedures. No injured or dead marine mammals or turtles were detected during approximately 185 hours of post-detonation aerial and vessel visual monitoring. Post-detonation monitoring resulted in observations of 767 marine mammals and 42 sea turtles. With only two exceptions, the same marine mammal and sea turtle species were observed prior to, during and after the shock trial test time period. Factors leading to the success of this environmental mitigation effort are summarised, and recommendations for improvements to mitigation efforts of this size and scope are suggested. These recommendations include the use of a simultaneous second aircraft for improved coverage during pre-detonation surveys, increased post-detonation aerial monitoring, equitable survey data for all test sites under consideration during planning stages, and reassessment of bio-acoustic monitoring need and purpose.

Distribution Characteristics and Pollution Assessment of Heavy Metals in Soils of a Testing Range

Heavy metal pollution in testing ranges is one of the most widely concerning environmental problems. The ammunition static detonation test area, the bomb falling area, and the living area of a testing range in Jilin were selected as the study objects. The contents of heavy metals (As, Cd, Cr, Cu, Ni, Pb, and Zn) in 112 topsoil samples and two soil profiles were analyzed, and their distribution characteristics and sources were analyzed in detail. After that, the pollution degree and potential ecological risk of heavy metals were investigated using multiple pollution index assessment methods. The results showed that the average contents of As, Cd, Cu, Ni, and Zn in the soil of the ammunition static detonation test area were higher than the soil background values in Jilin province, and the contents of Cu, Zn, As, and Cd showed strong spatial heterogeneity. The average concentrations of As, Cd, and Ni in the soil of the bomb falling area exceeded their background values. The average contents of As and Cd in the soil of the living area were higher than the background values, and the variation coefficients of Pb, Cd, Zn, and Cr were relatively high, indicating that they may have been affected by human activities. In different test areas, the contents of As, Cr, Cu, Ni, and Zn in the soil samples were significantly different (P<0.05). The ammunition static detonation test area was more strongly affected by the test activities than the bomb falling area, and the heavy metal contents in the surface layer of the soil profile were significantly higher. There was no obvious vertical migration of heavy metals in the soil profiles. The results of multivariate statistics and source identification analysis using absolute principal component score-multiple linear regression (APCS-MLR) showed that Zn, Pb, and Cd were mainly affected by pollution sources related to test activities; Cr and Ni were mainly affected by natural sources of soil forming materials; and the sources of As and Cu were more complicated. The geo-accumulation index showed that Cd in the three areas and Ni in the bomb falling area belonged to pollution level 1 (uncontaminated to moderately contaminated). The Nemerow comprehensive pollution index showed that the pollution levels among the different functional areas were:living area>ammunition static detonation test area>bomb falling area, and the three functional areas were slightly polluted. The potential ecological risk index showed that the study area was at moderate ecological risk level, and Cd was considered to be the main soil pollution factor.

Determination of thickness parameters of detonation shell and safety performance analysis

AbstractOn the premise of security, it is necessary to ensure good operational performance and technical indicators for nonlethal weapons such as flash detonation bombs. To make the weight of a flash detonation grenade more convenient for hand throwing and material costs save, the outer dimensions of the grenade body are fixed, and the optimal parameters of outer shell thickness of the vertigo grenade are explored. Based on the maximum deformation energy theorem, the strength of the shell with the obtained maximum thickness of 8 mm is checked, and then the optimal shell thickness under the ideal air explosion condition is obtained by reducing the thickness; Then check the thread strength to obtain the inner casing fracture, shock wave, and sound pressure level. The fragmentation performance test, detonation test, and sound pressure level test were carried out for the projectiles involving the shell thickness of 4 and 5 mm, and the simulation results were verified from three aspects of sound intensity, shell strength, and fragments. The results show that the maximum equivalent stress is 232.6 MPa and the maximum deformation is 1.07 × 10−4 mm when the outer shell thickness of the vertigo grenade is 5 mm, which is less than the material failure strength standard and no plastic deformation could occur. The structural connection strength of the missile body meets the standard. Most of the fragments are trapped in the cavity. The average sound pressure level at 1.5 m can reach 159.7 dB. The relative error between the sound pressure level at 3 m and the live ammunition test results is 4.8%, which meets the expected operational technical indicators and has good safety performance. The results of the numerical simulation can provide a reference for the design optimization and performance evaluation of similar vertigo grenades.

Synthesis of energetic coordination polymers based on 4-nitropyrazole by solid-melt crystallization in non-ionization condition

Based on the theory of crystallization, a solvent-free solid-liquid phase crystallization method called solid-melt crystallization was designed to prepare energetic coordination polymers. Two target compounds [Cu(NPyz)4NO3]·NO3 (ECPs-1) and Cu(NPyz)4(ClO4)2 (ECCs-2) were prepared through programmed heating and cooling by using 4-nitropyrazole (NPyz), (Cu(NO3)2·5H2O and Cu(ClO4)2·5H2O as raw materials. In addition, crystallization pre-experiments and annealing experiments also verified the feasibility of the method. Their structures were confirmed by IR, elemental analysis, single-crystal X-ray diffraction and powder X-ray diffraction. The physicochemical properties and sensitivity test results showed that ECCs-2 has better thermal stability (Td = 221 °C), while ECPs-1 is less sensitive to mechanical stimuli (IS = 12 J, FS = 240 N). Calculations based on EXPLO5 and the Kamlet-Jacobs equation showed that ECCs-2 has more considerable detonation performance (P = 25.2 GPa, D = 7.5 km/s). In comparison, the more intuitive results from the HN test, flame test, thermal resistance test and lead plate explosion test revealed that ECCs-2 has an “ acceptable” detonation performance. The laser detonation test also showed that ECCs-2 is a promising excellent laser detonation material (E = 408 mJ, P = 24 W, τ = 17 ms).

Blast resistance of RC tubular structure under internal ANFO explosion

The degree of structural damage is significantly more severe when a blast occurs inside than outside of a structure. However, existing designs for RC structures such as reinforced concrete containment vessels (RCCV) do not include design features to protect the structure for internal blast. Therefore, the internal blast resistance capacity of RC structures is evaluated by performing internal blast tests on RC tubular structures. The main objective of the study was to observe and document the basic structural behavior data obtained from internal detonation tests. ANFO explosive charge weights of 15.88, 20.41, 22.68 and 24.95 kg were selected for a charge detonating at a cross section center of the mid-span of the specimen, giving a standoff distance to the inner wall surface of 1000 mm. The data acquisitions include blast pressure, deflection, strain, and crack pattern. When the explosive charge weight increased from 15.88 to 24.95 kg, the peak incident pressure and time duration increased from 0.1718 to 0.3394 MPa and from 5.856 to 5.981 ms, respectively. Then, the test data were used to predict the internal charge weight required to fail a real scale RCCV using simple assumptions and the test data. The results of the study are discussed in detail in the paper.

Developing A Novel Small‐Scale Test to Predict Large‐Scale Explosivity

AbstractThere is a need for small‐scale (gram) tests that accurately predicts large‐scale (kilogram) detonation performance of energetic materials. Many attempts have been made to create such tests, but they are either too narrow in scope [1–3] or fail to demonstrate correlation with large‐scale behavior [4–9]. When creating regulations relative to safety and transportation, accurate small‐scale tests are crucial to organizations such as the Department of Defense, Department of Homeland Security, Occupational Safety and Health Administration, and the Pipeline and Hazardous Materials Safety Administration. Herein is reported small‐scale (15 g) detonation tests which can be reasonably correlated to large‐scale results. The protocol utilizes a ” diameter rate stick, booster to overdrive the sample, seeding with RDX, and evaluation of the run distance to failure using optical techniques. By these means we hope to develop reliable safety information prior to scaleup of production.

Research on performance of PBT/Bu-NENA low-vulnerability propellant

Large-size program temperature controller was used to carry out the slow cook-off test study of PBT, Bu-NENA, PBT/Bu-NENA mixture and PBT/Bu-NENA propellant in the range of gram and kilogram scale. The comprehensive performance of PBT/Bu-NENA propellant was carried out evaluation, including energy performance, mechanical performance, and low vulnerability performance (including fast cook-off test, slow cook-off test, shaped charge jet impact test and bullet impact test). The test results show that the slow cook-off response temperature of gram-weigh PBT, Bu-NENA and PBT/Bu-NENA mixture are 178.5°C, 142.3°C, and 139.0°C, respectively, while that of kilogram-weigh PBT/Bu-NENA propellant is 121.9°C. Analysis believes that high volatility of Bu-NENA plasticizers the main reason for the response temperature to drop from 139.0°C to 121.9°C. The PBT/Bu-NENA propellant has low vulnerability characteristics. Among them, the shaped charge jet impact test has the highest degree, which is an explosive reaction, and the sympathetic detonation test has the lowest response degree, which is below the burning. The theoretical special impulse of the PBT/Bu-NENA propellant is greater than 267 s,the density is greater than 1.80 g/cm3, the glass transition temperature (Tg) is less than -66°C, and the mechanical properties in the range of -60°C ∼ +70°C are excellent.

Preformed Fragment Velocity Distribution of Elliptical Cross-section Projectile

In the field of warhead design, non-cylindrical warhead, especially elliptical cross-section warhead, has received considerable attention. In this study, the initial velocity and distribution characteristics of the preformed fragments of a columnar projectile with an elliptical cross-section were examined. To obtain the velocity distribution of the fragments in this kind of projectile, three elliptical cross-section projectiles with different geometric sizes were test based on the static detonation tests. Then, the numerical models of the elliptical cross-section projectile have been established and validated according to the experiment results. Besides, two kinds of initiation types were studied by the simulation model, and the results indicate that not only the geometric size but the initiation type do great influences on the fragment velocity distribution in the direction of the axis. An empirical model was proposed based on the fragment two-step acceleration progress, and it was in good accordance with numerical results.

CFD analysis of large-scale hydrogen detonation and blast wave overpressure in partially confined spaces

The effect of confinement on the magnitude of overpressure due to a gaseous detonation of a hydrogen-air mixture was studied with the aid of numerical simulations. A simplified combustion reaction kinetic model applied along with computational fluid dynamics (CFD) allowed for the numerical simulation of large-scale detonations of hydrogen-air mixtures. The model was validated against experimental data reported in the literature for the case of a large-scale (300 m3) surface (unconfined space) detonation of a hydrogen-air mixture and the results of a hydrogen-air (confined space) detonation test performed in a 263 m3 tunnel facility. The predicted overpressure and detonation velocity was in agreement with the measurements in both unconfined and confined detonation cases. To verify the effect of confinement on the magnitude of the blast wave overpressure due to detonation of a combustible gas cloud, a series of CFD simulations of hydrogen detonations followed by propagation of a non-reactive blast wave in various geometries were carried out. The results were compared with the correlation applicable for unconfined detonations, which was also found to be applicable for partially confined detonations after the transformation of the distance from explosion centre to spherical blast wave equivalent radius.

Experimental study on TNT equivalent coefficients for two new kinds of propellants

The TNT equivalent coefficient is an important evidence to guide the blast-resistant design and safe-distance determination for dangerous goods. To find out the TNT equivalent coefficients of two new kinds of propellants (H1, H2), a series of free-field static detonation tests were performed for the two propellants (H1, H2) and flaky 2,4,6-trinitrotoluene (TNT). Five repeated tests were carried out for each explosive and the mass of the tested explosive was 10 kg in each test. And the existing method for calculating the TNT equivalent coefficients was modified. Base on the overpressure-time curves of the shock waves at different distances from the explosion centers, the TNT equivalent coefficients for overpressure and specific impulse at different scaling distances were analyzed by the modified calculation method. The results show that the propagations of shock waves induced by explosions of the propellants agree well with the similar law, and are similar with that induced by explosion of the TNT explosive. Meanwhile, the overpressures and specific impulses of shock waves induced by explosions of the two propellants are much higher than those of the TNT explosive. With the increase of scaling distance, the overpressure TNT equivalent coefficient of H1 first increases to 1.34 and then decreases, while that of H2 decrease monotonously, and the maximum value is 1.26. With the increase of the scaling distance, both the specific impulse TNT equivalent coefficients of H1 and H2 first increase and then decrease. The specific impulse TNT equivalent coefficient of H1 with the peak value 1.38 is greater than that of H2. The modified method can be used to accurately calculate the TNT equivalent coefficients of the tested samples, and the results can improve the safety design of blast-resistant structures.

Preparation and Properties of NC/TATB/Bu‐NENA/TMETN Low Sensitive Gun Propellants

AbstractSafety improvements in the field of energetic materials promoted the development of insensitive gun propellants. A low sensitive gun propellant was prepared by traditional extrusion using nitrocellulose (NC) as a binder, 1,3,5‐triamino‐2,4,6‐trinitrobenzene (TATB) as insensitive solid energetic filler, N‐butyl‐N‐nitramine (Bu‐NENA) as insensitive plasticizer, trimethylolethane trinitrate (TMETN) as co‐plasticizer, and graphite as thermal conductive filler. The density of gun propellants obtained was 1.611 g ⋅ cm−3 which was almost equaled to the theoretical density of 1.615 g ⋅ cm−3. The gun propellants exhibited excellent mechanical properties, especially cryogenic mechanical property, with the impact strength of 12.4 kJ ⋅ m−2 and the compressive strength of 157.1 MPa at −40 °C. The closed bomb test was conducted to investigate the energy and combustion performance. The results showed that the gun propellants had stable and regular combustion properties at a pressure up to 600 MPa. The burning rate pressure index n was about 1, and the impetus f and covolume α were 1045 kJ ⋅ kg−1 and 0.9764 cm3 ⋅ g−1 respectively. The vulnerabilities of the prepared gun propellants were evaluated by bullet impact, fragment impacts, sympathetic detonation, fast cook‐off, and slow cook‐off tests. The results showed that no response that was more severe than burning in test bombs was observed in bullet impact, fast cook‐off, and slow cook‐off tests under the given conditions. Moreover, a partially combustion reaction occurred in the fragment impact test with no obvious burning reaction in the sympathetic detonation test. It demonstrates that the prepared gun propellants possess good low vulnerability characteristics.

A facile strategy for synthesizing promising pyrazole-fused energetic compounds

A novel hydrazine-functionalized strategy is utilized for the synthesis of pyrazole-based energetic materials, giving rise to a new family of pyrazole-fused compounds and N-nitramine compounds with excellent properties. These new energetic materials are fully characterized by IR, 1H and 13C NMR and elemental analysis, as well as further confirmed by single crystal X-ray diffraction. All compounds exhibit high densities (1.816–1.882 g cm−3), good detonation properties (8323–8935 m s−1) and low sensitivities (IS > 15 J). Among these compounds, pyrazole-fused compound 5 features a striking thermal decomposition temperature of 302 °C and a better integrated energetic performance (D = 8935 m s−1, IS > 20 J, FS = 360 N) than that of RDX (D = 8795 m s -1, IS = 7.5 J, FS = 120 N). Furthermore, the results of detonation tests support the fact that 5 could be used as an applicable heat-resistant explosive and a replacer of HNS.