bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermal properties regulation of primary explosive based on adhesives’ composition effect
Authors: Lu Feipeng , Han Ruishan , Li Shaoqun , Wang Yanlan , Li Ming , Jiang Jiamin , Hu Gang
Published: December 2024

With the upgrading and development of weapons, primary explosive charge methods based on extrusion/printing technology had become important direction for the support capacity improvement for in service and novel equipment. Binders as the key component in extrusion/printing based primary explosive charge technology, its influence on primary explosives hadn’t been investigated, which shown important influence on energetic materials’ safety and reliability. Thus, primary explosive-binder compositions, (Nitrocellulose (NC), ethylcellulose(EC), and Viton (F) were employed as typical binders; meanwhile, lead azide (LA), silver azide (SA), and lead styphnate (LTNR) were employed as typical primary explosives), were prepared via water phase suspension method, and fully characterized its structure and thermal decomposition property. Hollow sphere structure was formed with NC and EC as binders, nanosheet could be find in the primary explosive-EC compositions. F based compositions shown primary explosive nano particles and aggregate blocks. EC shown more obvious influence effect to azide based primary explosives, which increased the decomposition temperature of LA, decreased the decomposition temperature of SA. F shown enhancement effect to LA’s thermal stability, and weak influence on the thermal stability of SA. These results could be attributed to the nanosheets structure of NC and EC in the composites. For LTNR, EC and F shown the weak effect to its decomposition temperature.
Study on thermal stability of HNS in adiabatic environment
Authors: Zhang Song , Wei Chunqiang , Teng Yiyi , Wang Zao , Chu Enyi , Wang Yanlan , Zhang Fang
Published: December 2024

The thermal stability of heat-resistant explosives plays an important role in their applications. This article uses adiabatic calorimetry to study the thermal stability of HNS-II, HNS-II, nickel chromium alloys of different quantities, and HNS-II after high-temperature storage in an adiabatic environment. SEM, XRD, and other methods are used to assist in analyzing the samples before and after decomposition. The results showed that the larger the sample size, the relatively less heat loss during thermal decomposition of the sample, and the faster the adiabatic decomposition rate. When the sample size was below 70mg, due to the endothermic effect of the sample ball, the temperature rise rate of sample decomposition was lower, and the decomposition process was relatively mild. The morphology of the residue after decomposition remained elongated; HNS II has good compatibility with nickel chromium alloy in adiabatic environments. In addition, compared with DSC, ARC can more accurately characterize the changes in material thermal stability: ARC testing shows that the thermal stability of HNS II has changed after high-temperature storage.
Optimization Design of Lattice Structures Based on Titanium Alloy Composite Reactive Materials
Authors: Wang Minghui , He Yuan , Zhang Rui , Ou Rongjiang
Published: December 2024

This paper proposes the use of active materials Al/PTFE and TC4 metal to form composite materials in order to enhance their mechanical properties. A lattice structure design based on the TC4 metal framework is developed, and three original crystal unit cells of the lattice structure are optimized according to the design concepts of Face-centered Cubic and Edge-centered Cubic. Seven crystal unit cells are simulated and modeled, and these lattice structures are then simulated at volume fractions of 0.25 and 0.35. The results show that regardless of the volume fraction, the mechanical performance of the optimized lattice structures surpasses that of common lattice structures.
Kinetics and mechanism of thermal decomposition of ammonium dinitramide by TG/DSC-FTIR and chip-DSC coupled with microscope
Authors: Haiyang Yu , Lei Huang , Huidi Dai , Limin Wang , Xing Zhou
Published: December 2024

Kinetics and mechanism of ammonium dinitramide were studied by the multiple methods composed of an in-situ testing thermal analysis system, product analysis by XPS/XRD/FTIR and evolved gas analysis using TG/DSC-FTIR. A three-step model for thermal decomposition of ADN was established, which were the low-temperature reaction, the single-step decomposition process with an autocatalytic reaction, and the multi-step decomposition process. N2O and NO2 were the main gaseous products, and there was difference in the intensity of the reaction at each stage. The corresponding kinetics and mechanism were proposed based on the analysis of activation energies and the intensity changes of the gaseous products.
Influence of structural parameters of layered interception compound reactive liner on combined penetrating and implosion effects
Authors: Wei Rongchao , Liu Yakun , Xiao Jianguang , Yang Yifang , Zhang Jinlin
Published: December 2024

In response to the bottleneck problem that the penetration depth of traditional fluoropyr-based reactive material(RMS) shaped charge is seriously insufficient, a Layered Interception Compound Reactive Liner (LICRL) shaped charge structure is proposed. Based on the MPM numerical simulation method, the influence of structural parameters such as the height ratio ϕ and thickness ratio η of the inner and outer liners on the jet formation and its penetration behavior is investigated. The results indicate that the variation in ϕ primarily affects the head shape of jet formation. When ϕ = 2/3, a composite jet comprising a precursor copper jet and a trailing reactive jet is formed, which causes a “Penetrating While Explosion” damage effect on steel targets. The variation in η mainly influences the shaping morphology of the copper jet. When η > 2/3, the damage power of the composite liner is weakened, this is attributed to the poorer shaping morphology of the coaxial copper jet under higher liner thickness ratios and premature fracture of the copper jet due to reactive material response. Compared to traditional single reactive jets, the layered interception compound reactive liner (LICRL) forms jets that penetrate steel targets to a greater depth, and significantly increase the crater diameter compared to single-metal jets.
Research progress of 1,1 ’- dihydroxyl - 5,5’ - ditetrazolium dihydroxylamine salt (TKX-50)
Authors: Minglei Chen , Nana Wu , Fengqin Shang , Kun Chen
Published: December 2024

1,1’-dihydroxyl-5,5’-ditetrazolium dihydroxylamine salt(TKX-50) is a new energetic ionic salt which has attracted wide attention at present. This paper reviews the research progress of TKX-50, including TKX-50 simple explosive and TKX-50 base mixed explosive. TKX-50 has certain application potential due to its advantages of easy synthesis, high energy, low mechanical sensitivity and low toxicity. However, compared with traditional CHNO energetic materials, TKX-50’s different crystal composition, interactions between particles in the crystal, thermal properties and its intrinsic nature, its less than ideal thermal stability and compatibility will limit its application. This indicates that the thermal response mechanism and energy release mechanism of the energetic ionic salt represented by TKX-50 May be different from that of traditional CHNO energetic materials, which needs further study.
Intelligent calibration of dual liner CCD intersection testing system based on Backpropagation neural network
Authors: peng Wang , Fangchao Xia , Zhongchen Cao , Jianbin Zhang , Zhenyi Zhang , Yongzhong Wang , Yutao Gu , Xuejun Chen , Lin Zhang , Weixi Yang
Published: December 2024

In order to improve the measurement accuracy and calibration efficiency of the dual liner Charge Couple Device (CCD) intersection measurement system, a calibration technique based on Backpropagation (BP) neural network is proposed. This calibration method does not consider the parameters of the linear CCD camera and treats the entire dual liner CCD intersection measurement system as a whole for calibration. In the testing of the dual liner CCD intersection measurement system, the pixel coordinates of the measured target in the pixel plane of the linear CCD camera will change with the actual position of the measured target. The position of the measured target is continuously changed multiple times to construct a training sample set. The BP neural network is trained using the constructed training samples, and the strong nonlinear mapping ability of the BP neural network is utilized to obtain the mapping relationship between the pixel coordinates of the measured target and the actual coordinates of the measured target in the dual liner CCD intersection measurement system. A dual liner CCD intersection measurement system was constructed, and calibration experiments were designed to compare and analyse the experimental data. The results show that the proposed method can improve the testing accuracy and stability of the dual liner CCD intersection measurement system, while also improving calibration efficiency.
3D printing technology and its potential applications in laser pyrotechnic systems
Authors: Li Yan , Zheng Wei , He Aifeng , Cao Chunqiang , Yu Xiaogang , Li Minjie
Published: December 2024

This article starts with the technical problems encountered in the development of laser pyrotechnic products, introduces the additive 3D printing technology, and combines application examples to introduce its molding process and characteristics. It mainly expounds the optical curing 3D printing technology used for optical device and optical system molding, as well as the integrated application of optical fiber and micro-lens. In the laser pyrotechnic system, it is required that the laser window can accurately focus the laser energy to the ignition powder surface, and be compatible with the miniaturization of the device and system. The 3D printing technology of an achromatic micro-lens based on the end face of the optical fiber, as introduced in this article, is of reference significance for improving the reliability of the laser pyrotechnic system and the miniaturization of the system.
Study on the Leakage Magnetic Field Characteristics of Multiple Halbach Magnetic Rings Based on the Equivalent Magnetic Charge Method
Authors: Wen Nai-Jin , Wang Hou-Sheng , Wang Jian-Chao , Ma Ben-Dong
Published: December 2024

A small astronomical detection platform needs to separate low-energy electrons from an X-ray beam. The Permanent Magnet Deflector (PMD) achieves electron deflection using its magnetic field. However, magnetic leakage can affect the operation of surrounding high-sensitivity instruments, it’s necessary to make a clear understanding of the leakage magnitude. Halbach magnetic rings can reduce magnetic leakage through an internally uniform unidirectional magnetic field and low magnetic density on the outer side. This paper proposes using the Equivalent Magnetic Charge Method (EMCM) to calculate the magnetic field of four Halbach magnetic rings at a distance. The magnetic field in space for Halbach magnetic rings with various magnetization directions is calculated using the Differential Element Method (DEM) combined with Orthogonal Decomposition Method (ODM). The calculation results are compared with finite element simulation results to verify the model’s accuracy. The study found that when the magnetization angles of the four magnetic rings differ by 180° around the x and y axes, the magnetic leakage is minimized at a distance. At a relatively close range, magnetic leakage is minimized when the magnetization direction changes by 90° in sequence. The results indicate that optimizing the arrangement of magnetization angles can significantly reduce magnetic leakage, providing a theoretical basis for the application of multi-Halbach permanent magnet arrays in space engineering.
Research on decomposition filter optimization algorithm of laser echo signal based on fractional fourier transform
Authors: Chen Zhuo , Zha Bingting
Published: December 2024

For laser echo signal, a decomposition filter optimization algorithm based on fractional Fourier transform is proposed. Faced with the problem of effective signal loss caused by empirical mode decomposition algorithm, the signal component is further filtered by Fourier transform, and then the signal is reconstructed. The denoising algorithm can reduce the signal loss under the condition of effective denoising, and the numerical simulation test proves the effectiveness.
Single photon detection based on photon driven mode for improving the depth reconstruction quality
Authors: Pei Zihao , Wang Bowen , Zeng Min , Zuo Chao
Published: December 2024

In the single photon detection, the precise time of flight (TOF) between the target and the detector is very important to retrieve the depth information with high quality. It is hard to obtain in the practical experiment due to the existence of the system jitter, the background noise and the dead time, respectively. In this letter, a single photon detection method based on photon driven mode is proposed to improve the depth reconstruction quality. An additional reference signal is added to suppress the delay of the system. The photon driven model is built to explore effects of the dead time on the incident photon sequence. Finally, the incident photon sequence retrieved by maximum likelihood estimate (MLE) is filtered by a butterworth filter to improve the depth information.
Simulation and experimental analysis of explosive reactive armor collateral damage
Authors: Peng X F , Xiang H , Liang J Y , Zhong Y W , Bai F Q , Huang W B , Gao Y L , Yang Y
Published: December 2024

Addressing the issue of collateral damage caused by the structural design of explosive reactive armor (ERA) containers to close-combat units, this study combines simulation with experimental validation to focus on the damage intensity and range of ERA package side strips on target plates at different distances and positions during the defense against long-rod penetrators. Simulation analysis shows that the main collateral damage of the explosive reactive armor is the side strip of the cartridge flying in the normal direction of the target plate, and the fragmentation speed is about 760m/s. The experimental results show that collateral damage is relatively minor to the rear-side but concentrated primarily on the frontal-side. Under the action of explosion, the flight path of the side strip of the plate cartridge is stable, and the degree of collateral damage caused by it is the greatest. The flight path of the side strip is mainly in the range of the vertical scattering Angle of about 33° and the horizontal scattering Angle of about 31°. The distance attenuation of shock wave is much greater than the velocity attenuation of fragment, making debris the primary factor in collateral damage. The fragment speed range is 700m/s∼800m/s, the diameter (or length) of the penetrated hole is about 8mm∼20mm, and the fragment size is about 6mm∼10mm
Experimental study on the effect of energy absorption and wave attenuation of sand wall in ground motion under explosion
Authors: Song Shiqian , Shi Yongxiang , Li Zengyue , Huang Xiaofei , Xing Yuanding
Published: December 2024

Sand walls have a good energy absorption and wave attenuation effect on explosion shock waves, which can also have an impact on the seismic waves generated by the evolution of shock waves. In order to study the effect of sand wall in energy absorption on the results of explosive ground motion, four repeated explosion experiments were conducted by using different sand wall configurations. A ground motion measurement system was designed to measure the velocity at different distances from the explosion center. The measurement and analysis results showed that under the action of the sand wall, the peak velocity and the total energy based on vibration velocity both significantly decreased, fully demonstrating the energy absorption and wave attenuation effect of the sand wall. The sand wall also has an impact on the cube root similarity rate, resulting in the distribution of ground motion parameters no longer strictly following this law, but the sand wall has no significant impact on the frequency distribution. Under different sand wall configurations, the circle shaped sand wall has a better energy absorption and wave attenuation effect, while the circle shaped sand wall with nested circle shaped ends can enhance the energy absorption and wave attenuation effect by 21%.
Determination and verification of parameters in the dynamic constitutive for Inconel 718 superalloy
Authors: Yang L F , Wen H M
Published: December 2024

Inconel 718, which is a nickel-based superalloy material used in aero engines, may be subjected to intense dynamic loading in an accidental engine failure. However, the material models for Inconel 718 employed in existing studies can not describe the mechanical behaviors under complex stress states, high strain rates and elevated temperatures satisfactorily. In this paper, various parameters of a previously proposed dynamic constitutive model for Inconel 718 are determined and verified. First, the parameters of strength, strain rate effect, temperature effect and failure for precipitation hardened Inconel 718 are calibrated against various material tests. Then, the parameters are verified by comparing the numerical results obtained from the dynamic constitutive model with the corresponding ballistic test data. It transpires that the numerical results agree well with the test data, which demonstrates the accuracy and effectiveness of the dynamic constitutive model for Inconel 718. It can also be concluded that the consideration of Lode angle effect and precise descriptions of strain rate and temperature effects are significant for the reproduction of mechanical responses of Inconel 718 plates under intense dynamic loadings in numerical simulations.
Novel damage criterion in database form based on component-level vulnerability assessment
Authors: Feng Bo , An Fengjiang
Published: December 2024

Target vulnerability assessments commonly involve large and complex components such as engines exhibiting a lack of systematic and comprehensive representation of damage criteria. This study presents a novel approach to characterizing the damage criteria of large and complex components when impacted by fragments in the form of a database. The damage criteria are formulated based on component-level vulnerability assessments and presented in tabular format, providing information on the component damage probability under the impact of fragments with different velocities, masses, and directions, as well as the residual velocity and mass data for fragments passing through the component. A servo is chosen as a representative component to establish damage criteria in the form of a database. Steel fragments, with masses ranging from 4 g to 7 g and velocities from 100 m/s to 1800 m/s, are employed to impact the servo component from 26 different directions. A total of 1144 sets of vulnerability data for the component are collected, including the damage probability of the servo and the residual mass and velocity of fragments. These data serve as comprehensive damage criteria for the servo component. A comparison between these component damage criteria in a database form with those derived using an equivalent target method shows that the former approach offers greater accuracy and adequacy in representing the damage characteristics exhibited by large and complex components than the latter. the proposed method in this study to represent damage criteria for large complex components in the form of a vulnerability database has broad application prospects and provides new ideas for future research on damage criteria for components.
Experimental and numerical study on jet penetrating multi-layer metal rubber air-spaced composite target
Authors: Qiong Qi , Lei Zhang , Xun-cheng Guo , Dong-jiang Zhang , Yun-hui Hou
Published: December 2024

A multi-layer metal rubber air-spaced composite target was designed. Based on the 140 mm caliber shaped charge, the penetration test and simulation study were carried out. By analyzing the damage of the target plate and the interaction process between the jet and the target plate in the simulation, the interference mechanism of the composite target to the jet is revealed. The equivalent armor thickness and anti-jet penetration ability of the composite target under oblique penetration with large inclination angle are obtained by using the equivalent criterion of residual penetration depth. It is concluded that the multi-layer metal rubber air-spaced composite target can not only reduce the load of the armored vehicle, but also has good anti-jet penetration performance, which can provide support and basis for the design of other rubber composite target structures.
Study on the Damage Effect of Shaped Charge Jet Penetrating Multi-layer Spaced Inclined Target Plates
Authors: Wang M , Qiu J W , Chen X W , Wang Y S , Liu F
Published: December 2024

This study aims to investigate the formation characteristics and penetration performance of multi-layer spaced inclined target plates by shaped charge jets. Based on a multi-material fluid-structure interaction algorithm, a three-dimensional simulation model of a shaped charge jet penetrating multi-layer spaced inclined target plates was established. The process was numerically simulated using a nonlinear finite element program. Relevant validation experiments were conducted, and the causes of discrepancies between numerical simulations and experimental results were analyzed. The effect of the target plate placement angle on the damage effect of the shaped charge jet penetrating multi-layer spaced inclined target plates was discussed. The results show that the numerical simulations are in good agreement with the experimental results. The impact of the shaped charge jet on the spaced inclined target plates diminishes as the placement angle increases. The penetration time and velocity reduction values of the jet on various target plates at different angles were measured. It was found that the size of the openings in the target plates positively correlates with the placement angle, and the symmetry of the opening shapes degenerates with increasing placement angles.
Study on the blast resistance of concrete reinforced with multi-scale hybrid fibers
Authors: Chengyuan Wang , Zhijun Wang , Zhijun Cheng
Published: December 2024

Hybrid fibers can greatly improve the toughness of concrete and enhance the blast resistance of concrete. In this study, nano-sized multi-walled carbon nanotubes, micron-sized calcium carbonate whiskers, and millimeter-sized steel fibers were added to the concrete to improve the cracking resistance of the concrete on a nano-micron-millimeter multi-scale. The blast resistance of multiscale hybrid fiber-reinforced concrete with different TNT equivalents and the volume content of steel fiber were investigated by numerical simulation methods. The results showed that, with the addition of multi-scale hybrid fibers, the concrete plate in the TNT equivalent of 200 g occurred in a moderate degree of delamination failure, in the 400 g TNT equivalent, the MSHFPC plate penetration damage occurred, compared with the plain concrete plate, the blast resistance significantly improved; the explosion pit diameter with the increase in the TNT equivalent increased; with the increase in the volume content of steel fibers, the number and length of cracks in concrete plates significantly decreased, and the blast resistance performance significantly increased.
Damage Patterns and Boundary Research on the Internal Explosion of Shell-Encased Warhead within Compartments
Authors: Deyang Zhang , Xingxing Wu , Juan Chen , Nu Zhang , Yanjie Zhao
Published: December 2024

This paper primarily focuses on basic ship compartment as the research object, conducting experiments on internal explosion of shell-encased warheads to ascertain the corresponding damage patterns and the damage boundaries under current conditions. Additionally, numerical computation methods are employed to gain a more detailed understanding of the entire transient testing process and to validate the reasonableness of the computational models. Based on the experimental data, observed phenomena, and simulation results acquired, this paper draws the following conclusions: for internal explosion test of shell-encased warhead, the theoretical formula provides good prediction for the shock pressure, but there is a considerable discrepancy in the quasi-static pressure; a comparison between simulation and test results shows that the damage pattern from the internal explosion of an equivalent mass of bare charges within a compartment is consistent with the experiment, although the damage boundary is underestimated; under the current test condition, the damage boundary of the warhead extends beyond three compartment walls. The research presented in this paper can better inform the design of naval structures and provided foundational experimental data for the internal explosion of shell-encased warhead within compartments.
Study on the Constitutive Relationship and Mechanical Properties Fitting of SFRC Based on Optimized BP Neural Network
Authors: Ma Pengsheng , Zhou Fengjun , Liu Li , Li Feng , Kang Huaiqiang , Gao Hang , Sun Yunhou
Published: December 2024

In order to accurately characterize the complex mechanical behavior of steel fiber reinforced concrete (SFRC) under high-speed impact and accurately describe the constitutive relationship of its mechanical behavior, the dynamic compression test of plain concrete and SFRC with two different fiber contents, 0.5% and 1.5%, was carried out based on the split Hopkinson pressure bar (SHPB). Firstly, the stress-strain curves and their failure morphology at different strain rates in the range of 47s−1-214s−1 are obtained; Next, a back propagation (BP) neural network prediction model optimized by particle swarm optimization (PSO) algorithm was established based on SFRC stress, taking strain rate, fiber content, and true strain as input parameters, and outputting the true stress; Finally, the fitted constitutive relationship of SFRC is obtained by inference based on the established model. The results show that SFRC has a strong strain rate enhancement effect in strength, and its peak stress will be continuously enhanced with the increase of strain rate. The steel fibers can effectively inhibit the generation and expansion of cracks, thereby improving the impact resistance of concrete. The PSO-BP neural network model proposed in this paper can effectively fit the constitutive relationship of SFRC, and the deviation of the model inference results is less than 10%, with the model correlation coefficient R of 0.9563 and the average relative error E of 5.92%. At the same time, the proposed model can also be used for the prediction of the performance indexes of elastic modulus and ultimate compressive strength, and the model has a good generalization ability and good fitting accuracy.
Compressive Mechanical Properties of a New High Density NiW Alloy
Authors: Yang Jincheng , Chen Chunlin , Ma Kun , Cao Jin , Yin Lixin , Gao Pengfei , Feng Na
Published: December 2024

In order to apply a new high density NiW alloy to hollow kinetic energy penetrators, the mechanical properties of the alloy at high temperature and high strain rate are studied by Hopkinson pressure bar. The results show that the strength of the alloy decreases significantly with the increase of temperature, and the decreasing rate between 900°C to 1200°C is about 4 times that between 25°C to 900°C; the alloy has a strain rate strengthening effect, and the strain rate sensitivity increases with the increase of temperature under dynamic loading; unlike normal metals, the tangent modulus of the alloy does not decrease monotonously with the increase of temperature due to the precipitation of Ni4W phase, the solid solution strengthening mechanism and the dynamic recovery mechanism jointly determine the trend of the tangent modulus.
Numerical study on the effect of initial detonation points on energy output structure
Authors: Ying Yuan , Guotao Yang , Yongxin Wen , Yilei Li
Published: December 2024

A numerical simulation was employed to investigate the influence of initiation modes on the energy output structure of cylindrical explosives. Based on the numerical simulation results of the response behaviours of identical explosive configurations under different initiation scenarios, including one-end initiation, two-end detonation, centre point detonation, and axial detonation, combined with the development and propagation rules of detonation waves as well as the response behaviour of the shell, the temporal and spatial distribution characteristics of the output energy distribution of explosives under various initiation modes were obtained. The research findings provide a theoretical foundation for the design of explosive initiation points, the regulation of the directional energy output of warheads, and the enhancement of energy utilization efficiency.
The Protective Capability of Helmet Against Blast Wave to Prevent Traumatic Brain Injury
Authors: Wenchao Zhang , Bin Qin , Liang He , Yang Wu
Published: December 2024

Blast-induced traumatic brain injury (b-TBI) is a kind of prevalent military injury in combat casualty care, yet little is known about the protective capability of typical helmet structure against blast wave. In this study, a head model under blast was used for experimentally and numerically research. A finite element model with a typical human head structure was established. Tests on the distribution of air pressure field of the unprotected head, typical combat helmet protected head, combat helmet protected head with face shield, motorcycle helmet protected head were carried out after the explosion of 50gTNT action at 1m. Various test conditions were analyzed by numerical simulation method. The interaction law between the blast wave and the head under the protection of different helmet structures was obtained. Combined with the brain tissue pressure, the protective effect of different helmet structures on the blast wave was analyzed. The results show that increasing the helmet protection area is a good protection strategy for blast wave and the research suggests a possible protection strategy for blast wave often associated with military concussions.
Effect of considering thermoplasticity of gun steel on thermomechanical coupling response of barrel
Authors: Wang Haoyu , Fu Jiawei , Chen Longmiao , Liu Nailin , Pang Jianing
Published: December 2024

To explore the effect of considering thermoplasticity of gun steel on the thermomechanical coupling of the barrel during artillery firing, the thermoplastic coupling behavior of the barrel under transient thermal and mechanical loads is investigated. A thermomechanical coupling finite element model of the barrel was established. The transient temperature field and stress field of the barrel during the gun firing process were analyzed. By comparing the results of the thermoelastic model with that of thermoplasticity model, the effect of considering thermoplastic of gun steel on thermomechanical coupling response of barrel was investigated. The results show that the peak of Mises stress evolution considering thermoplasticity of material in the bore of the barrel is significantly reduced during the gun firing process, and the hoop stress evolution appears double-peak phenomenon. In addition, at the peak moment of bore pressure, the peak values that the hoop and Mises stress distributions along the radial direction at the midpoint of the land are reduced by 14.5 % and 20.9 %, respectively. This paper can provide a reference for the design of a large-caliber barrel.
The attenuation characteristics and optimization design of polyurethane foam bulkhead to blast wave
Authors: Shouren Wang , Pengwan Chen , Chuan Zhao
Published: December 2024

Polyurethane foam has the characteristics of low density, nonlinear mechanics and energy absorption, and has been widely used in the research of shock wave attenuation. In order to realize the effective attenuation of the blast wave, the attenuation process of the shock wave in the medium is simulated by Autodyn. The impact ignition simulations were carried out for the Comp B impact ignite TNT under the bulkheads. The results show that the explosion-proof performance of the composite bulkhead is signi2icantly better than that of the single medium bulkhead. The combination of PR 6720 (polyurethane foam) and 45#steel can greatly attenuate the blast wave. The impact impedance matching relationship of the bulkhead and the medium on both sides should be used as an important design factor when designing the bulkhead.
Study on the Formation Characteristics of Composite Damage Elements
Authors: Zheng Juhong , Yu Rui , Wang Yajun , Zhao Junmin
Published: December 2024

More innovative and high technologies are being emerging endlessly, and more requirements for comprehensive damage effect have been further proposed. As a results, the single usage method and damage effect can no longer fully fit the future trends. In this paper, the formation characteristics of EFP and the scattering characteristics of prefabricated fragments was studied on the basis of the structure with composite damage elements, such as prefabricated fragments and explosively formed penetrator (EFP). The results show that the composite damage elements can form high-velocity projectiles with an initial velocity of 2230 m/s in the axial direction and a tungsten ball array with the scattering velocity in the range of 750 to 840 m/s. Moreover, if prefabricated fragment structures are removed, the change of EFP formation characteristics is not obvious. However, shaped-charge structure play an evident influence in the scattering velocity of fragments. Compared to the structure with single damage elements, the average velocities of fragments of composite structure are higher and its scattering angles are more widely, maximum scattering angle increasing from 16° to 20.1°.
Fragmentation Process and Combustion Performance of the Grain-molded Gun Propellant
Authors: Jia ZJ , Hu XB , Liu ZY , Yan WR , Wen XM , Cui HL , Li CH , He L
Published: December 2024

In order to research the impact fragmentation and combustion behavior of the grain-molded gun propellant and guide the design of ammunition charge structures, experiments were conducted using constant-volume gas pressure impact and closed bomb tests. Tests were conducted and results were obtained, including the combustion pressure variation curves of the grain-molded gun propellant as well as its disintegration and fragmentation states under different termination pressures. The study analyzed the impact fragmentation process and the progressive combustion characteristics of the grain-molded gun propellant.. The results show that the combustion of the molded gun propellant does not follow the parallel layer combustion rule; The molded gun propellant exhibits inconsistencies in burning rate and disintegration fragmentation, making it difficult to achieve simultaneous ignition and combustion. Additionally, the molded gun propellant can reduce the gas generation rate during the initial stage of cartridge firing, thereby extending the combustion duration.
Study on the forming of eccentric sub-hemisphere tungsten tantalum alloy liner
Authors: Yu Wang Zhe , Bing Li Wei , Bin Li Wen , Ming Wang Xiao
Published: December 2024

In order to obtain a tantalum tungsten alloy rod penetrator structure with good performance indicators, LS-DYNA numerical simulation software is used to study the effects of different structural parameters (such as curvature radius of liner, liner thickness, liner thickness variation rate, eccentricity, and the height of charge) of the eccentric sub-hemispherical structure liner on the formation of Ta-2.5W rod penetrator, and the optimal range of each structural parameter is determined. Through orthogonal optimization design, the primary and secondary order of the influence of various structural parameters on the formability of Ta-2.5W rod penetrator is obtained, and the optimization scheme for Ta-2.5W rod penetrator is determined (the internal curvature radius R2
of the liner is 0.9571Dk
, the top thickness t of the liner is 0.0286Dk
, the eccentricity d of the liner is 0.0429Dk
, the thickness variation rate s of the liner is 1.25, the diameter Dl
of the liner is 0.9Dk
, and the charge height l is 1.0Dk
, where Dk
is the charge diameter). The results show that the optimized Ta-2.5W rod penetrator scheme has good performance indicators, with a speed V of 1830.7m/s, an aspect ratio L/D of 7.13, a compactness N of 0.84, and a necking ratio M of 0.30. Compared to pure tantalum, the Ta-2.5W rod penetrator is superior because pure tantalum will break under the same working conditions.
Damage effectiveness evaluation of a certain type of submarine
Authors: Hao Li , Wenbin Li
Published: December 2024

In order to evaluate the damage effectiveness of a certain type of submarine, through the analysis of the vulnerability of the target and the calculation of the explosive power field, the damage effectiveness evaluation platform of the submarine is built, and the missile-target rendezvous parameters are set up, and different schemes are established, the damage effectiveness evaluation of the submarine model is completed. The results show that the damage effect of torpedo is the best among different parts of submarine, the damage probability of heavy torpedo is 97.51%, and that of light torpedo is 91.18%.
Study on the Effects of Multiple Macroscopic Deviations Coupling on the Jet Formation Performance of Shaped Charges
Authors: Xu Hengwei , Lu Zhengcao , Liang Bin , Lu Yonggang
Published: December 2024

To improve the penetration stability of shaped charges, this study investigates the influence of three common types of macroscopic manufacturing deviations—off-centre initiation, liner offset, and liner deflection—on the jet formation performance of shaped charges. The study employs variance analysis to elucidate the relative significance of each macroscopic deviation. The findings indicate that off-centre initiation causes the jet to deflect while maintaining a linear shape, whereas liner offset and deflection deviations result in jet bending. When multiple macroscopic deviations are coupled, the degree of jet bending approximates the vector sum of the bending induced by individual deviations.
Theoretical Study on Impact Compression Behavior and Reaction Characteristics of Reactive Materials
Authors: Du Ning , Song Xiaoyu , Sun Yinglue , Guo Qiuping , Dong Xing , Huang Weiping
Published: December 2024

Reactive Materials (RMs) is usually inert at normal temperature and pressure, but when it is subjected to enough impact energy, it can be rapidly transformed into a high-temperature and high-pressure environment, which triggers a chemical reaction and releases a large amount of energy. In order to study the impact compression behavior and reaction characteristics of RMs, this paper established a typical Al/PTFE RMs impact reactivity calculation equation based on the Arrhenius reaction rate model and combined with Avrami-Erofeev’s n-dimensional nuclear/growth control reaction model. And theoretical calculations were conducted on the impact response and reaction characteristics of typical Al/PTFE RMs. The reliability of the model was verified by comparing the calculated results with the simulation results. At the same time, the propagation process of shock wave pressure peak under explosive load in RMs was numerically simulated using software, and the propagation law was studied. The results showed that the impact pressure had a significant impact on the energy release characteristics of typical Al/PTFE active materials. The calculation results of the critical reaction threshold for impact are in good agreement with the simulation results, indicating the reliability of the model. The size of the explosive charge remained unchanged, and as the propagation distance of the shock wave increases, the peak pressure of the shock wave attenuated slowly in the Al/PTFE RMs. During the explosive loading process, the Al/PTFE RMs did not undergo complete chemical reactions, and only a portion of the RMs underwent chemical reactions.
Mesoscale simulation study on formation of reactive double-layered liner
Authors: Qiu Wenhao , Zheng Yuanfeng
Published: December 2024

A mesoscale numerical simulation model of double-layered liner with reactive material and copper is established by means of mesoscale numerical simulation method. The mesoscale morphology, velocity characteristics and the force-thermal coupling characteristics of reactive material during the formation process are studied by simulating the double-layered liner with typical structure. Six kinds of double-layered liner with different liner thickness ratios are simulated to study the influence of liner thickness relationship on formation. The main results are as follows: The slug is almost completely formed by the reactive outer layer liner, and the jet head is completely formed by the inner liner. The slug speed is about 450m/s, the jet head speed is about 5000m/s, PTFE and Al material speed is basically the same, there is no velocity gradient; The pressure and temperature of reactive outer layer liner are positively correlated. The impact temperature rise of reactive material is low due to the wave impedance characteristics of double-layered liner, which may lead to a low degree of activation. In addition, the jet length and head velocity decrease with the increase of total liner thickness. The liner thickness is increased from 1mm/3mm to 2mm/5mm, the jet length is shortened by 20%, and the head speed is reduced by 15%; At the same time, the thickness of copper inner layer liner has a greater influence on the jet length, and too thick liner will have a negative effect on the pressure and temperature of the jet.
Numerical simulation of ballistic protection performance of circular and hexagonal perforated high nitrogen steel
Authors: Shi Anshun , Hong Xiaowen , Xia Kailang , Sun Sujie , Fan Xuefei , Qin Chao , Zhao Hongyuan , Han Hongwei , Ge Yuanyuan
Published: December 2024

The ballistic performance of high nitrogen austenitic stainless steel (HNASS) plates with round and hexagonal perforations was numerically simulated by LS-DYNA software. A systematic analysis was conducted to explore the effects of pore size, hole spacing, impact point, and other variables on the material’s ballistic resistance. It indicate that the failure mechanism of the bullet core penetrating the perforated HNASS plate is dependent on the specific impact point. Additionally, circular perforated plates exhibit superior crack arrest capabilities compared to hexagonal perforated plates. When the width of the steel plate between adjacent holes exceeds the hole radius, there is an increase in core mass loss, both at the center of the hole and at the impact point between two holes. The deflection angle of the bullet core is significantly affected by the impact point, particularly when the width of the steel plate between holes is greater than the hole radius, with a maximum deflection angle of approximately 20°. Factors such as the hole diameter of the perforated plate, the width of the steel plate between holes, and the shape of the perforations all influence the residual velocity of the bullet core. Generally, smaller hole diameters, wider steel plates between holes, and hexagonal perforations result in lower residual velocities of the bullet core. Notably, the hexagonal perforated plates demonstrate a lower residual velocity compared to circular perforated plates, with a maximum average velocity drop that is 43.8% higher. The findings can serve as valuable references for designing additional armor for light armored vehicles.
Initial velocity circumferential distribution model of Multi-layer spherical premade fragments
Authors: Qifei Meng , Jianbing Men , Yuxiang Nan , Shiyu Liu
Published: December 2024

To calculate the force field of multi-layer spherical premade fragment warheads, a calculation model for the initial velocity of multi-layer spherical fragments is constructed. Based on the scattering process of multi-layered spherical fragments under explosive loading, the fragment driving process is divided into three stages: common motion, filler penetration, and fragment delamination. A multi-layer spherical fragment circumferential initial velocity calculation model was constructed by combining the Stanovich model and Gurney model, using the momentum theorem and energy conservation law. Conducting numerical simulations and pulse X-ray verification experiments on the explosive loading of fragment warheads under different levels of fragment layers, the numerical simulation and experimental results show that when the number of fragment layers is less than 4, the average velocity of each layer calculated by the model has an average error of less than 15% compared to the simulation and experiment, which can basically achieve prediction of the initial velocity and distribution of premade fragments scattered along the circumferential direction in each layer.
Capacitor cell with boosted switching-on
Authors: Enikeev R , Fridman B , Korkunov A , Sapozhnikov K , Tomashevich P , Vasil’ev A , Popkov D
Published: December 2024

The paper presents the results of the development and experiments of a capacitor cell with stored energy up to 121.875 kJ with boosted switching-on, designed to operate at voltages up to 50 kV and a maximum discharge current amplitude of up to 500 kA. The cell has two circuits. The “fast” circuit, switched using a pseudo-spark switch, provides the initial boosted switching-on and increase in voltage in the load, and the main “slow” circuit, switched using trigger vacuum switches, ensures a subsequent increase in the current to the required value.
Combustion enhancement and control of modular charge by electrothermal plasma
Authors: Yang Xuqing , Wang Zhangfei , Liu Jian , Li Baoming
Published: December 2024

Uni-modular charge has the advantages of easy automatic loading, fast loading speed, high safety and easy logistics support, which is the best choice for large calibre artillery charge. For uni-modular charge, the small number modular charge has some problems, such as ignition inequality, propellant combustion instability, and easy residue, which results in chamber pressure surge and low firing accuracy. Electrothermal plasma has the advantages of high temperature, high heat enthalpy and fast chamber diffusion, which is a feasible way to solve the problem of modular charge combustion. The key technologies such as plasma generator and high-power breech transmission have been studied, and the large calibre modular charge electrothermal chemical launch system has been established. Electrothermal chemical launch test was conducted. It is verified that electrothermal plasma can significantly enhance the firing performance of the small number modular charge.
Research on transmission line capture algorithm based on AI ISP
Authors: Li Mingyue , Cui Wenpeng , Tian Zhizhong , Yang Bokuan , Yang Qingchen , Chen Yuzhe
Published: December 2024

Routine power inspection is crucial for the safe operation of the power system, and unmanned aerial vehicle (UAV) inspection methods are commonly used for power inspection. However, there are still challenges in improving the quality of captured videos and images during UAV inspection. More and more researchers are introducing AI ISP methods to improve the image quality of transmission lines in harsh scenarios such as night, foggy, and rainy days. This article designs a dual-branch model based on AI ISP technology, which takes Raw data and HVI spatial data as inputs, extracts their respective features, and fuses them as outputs. The model is experimentally compared on multiple public datasets and validated on the self-made transmission line inspection data in this article. This article achieved SOTA performance on the aforementioned datasets.