bluuebunny/crossref_metadata_2025_split huggingface dataset:
Protective performance of helmets based on the shock wave from rocket launcher
Authors: Wu Yang , Qin Bin , Zhang Xianfeng , Lu Haitao , Xiong Manman , An Shuo , Liu Shuang 
Published: December 2024

Abstract
Traumatic brain injury(TBI) is one of the most common cause of major casualties in the battlefield. Soldiers may be endangering their brains when they operate certain shoulder-fired weapons or large-caliber artillery for long periods of time. It is necessary to pay attention to protection and prevention of brain injury in daily training. In this paper, the characteristic of shock wave propagation on the head with/without helmet protection when soldiers operated shoulder-fired rocket-propelled grenade launcher. The head-helmet surrogate was constructed in combination with pressure sensors. The pressure sensors were installed on the forehead, temples, top, and back of the head surrogate respectively and the sensors kept a plane with the surface of the head surrogate. The pressure variation of the shock wave flow field under different working conditions was analyzed in three types such as with/without combat helmet and integrated helmet. The results show that the peak overpressure of the shock wave from the back of the head can reach 80∼105kPa without combat helmet. The combat helmet can effectively reduce the shock wave overpressure. The integrated helmet has the best protection and can reduce the overpressure on the forehead, temple, top, and back of the head by 73%, 58%, 80%, and 83% respectively. Meanwhile the shock wave is prone to reflection and diffraction as it transmits inside the helmet. This significantly increase the overpressure of the shock wave on the forehead and the duration of the shock wave in the helmet, which has a negative effect on the protection provided by the shock wave.
Analysis and Research on the crack of a type of pressed PBX column
Authors: Yang Xiong , Lü Xi , Jia Xian-zhen , Sun Feng , Guo Xiaowei , Hao Gang , Li Shuaixiao , Huang Yafeng 
Published: December 2024

Abstract
In this paper, aiming at the crack found in a type of press loaded PBX column during ammunition charging, in order to reveal the cause of the crack, the industrial CT nondestructive testing technology was used to scan and analyze the column. The results shown that there was a bulge on the column surface in the crack area, and the internal structure of the bulge was a clearance surface parallel to the outer surface of the column; The finite element method was used to simulate the stress distribution in the pressing process of explosives and the stress after the column collides with the rigid plane. The simulation results of the pressing process shown that the stress concentration area and the area with the first plastic deformation were not at the crack position, but at the corner of the central hole; The rigid plane simulation results of column collision shown that the stress wave propagates in the axial and radial direction, which was consistent with the crack morphology and crack propagation direction on the surface of explosive column, and also matches the internal morphology of column crack. Through comprehensive analysis and judgment, the crack of the pressed PBX column was more likely to be caused by external force collision, and the probability of being caused by internal stress was very small.
Analysis of Factors Influencing the Reaction Intensity of Composite Propellants with Different Casing Materials under Slow Cook-off
Authors: Liang Jiahao , Nie Jianxin , Zhang Haijun , Zhang Leilei , Li Yingjun , Guo Xueyong , Yan Shi 
Published: December 2024

Abstract
By conducting slow cook-off tests on solid composite propellants, the combustion response characteristics of propellants under different casing materials were investigated. Propellant slow cook-off combustion experiments were designed and carried out. Combining the morphological changes of propellant thermal decomposition weight loss with theories of material mechanics and heat transfer, the heat transfer process and physical state of the propellant before ignition were examined to explore their effects on after ignition reaction intensity. The results indicated that the reaction intensity varied with different casing materials. When the casing material is 45# steel, spontaneous ignition occurred at 214.88, with a slider speed of 14.83 m/s, classifying the reaction as deflagration. For 2A12 aluminum casing material, spontaneous ignition occurred at 199.13, with a slider speed of 0.71 m/s, classifying the reaction as combustion. When the casing material is carbon fiber composite, the reaction was classified as combustion. Different casing materials influence the reaction intensity through their thermal physical parameters and casing constraint strength, providing guidance for the selection and design of casing materials and constraints in slow cook-off combustion of motors.
Study on the gas pressure impact test of gun propellant and fluid-solid coupling dynamics simulation
Authors: Zhang R H , Chen D Y , Liu J H , Zhao H L , He C H , Jin J W 
Published: December 2024

Abstract
In order to reveal the mechanical response characteristics of high-energy propellant under high pressure gas impact, the gas pressure impact test and fluid-solid coupling dynamics simulation of propellant are carried out. The propellant gas pressure impact test device is established. The propellant gas pressure impact tests are conducted under different quality of depressant and thickness of iron pressure relief fragments. The gas pressure-time curve, gas pressure rise and decreasing rate are obtained. It is found that longitudinal and transverse cracks occur locally in propellant under high pressure impact. In order to reveal that mechanical property change of propellant under gas impact, the simulation study on fluid-solid coupling dynamics of gas pressure impact test is carried out using ANSYS Workbench multi-field coupling platform. The flow field pressure in the device and the change process of fixed propellant stress and deformation are obtained. The error of monitoring point simulation and test pressure is 5.3%. The maximum peak value of internal flow field pressure reaches 71.6MPa. The average value of maximum stress and maximum deformation of fixed propellant reaches 220MPa and 1.77mm respectively. It reveals the mechanical response characteristics of propellant under high pressure gas impact.
The Equivalence Method of Overload Characteristics of Detonation Control System based on High-speed Deep Penetration of Composite-medium Thick Target
Authors: Yan Huan , He Hongwei , Hu Qianyu , Huang Dan 
Published: December 2024

Abstract
In response to the improvement of the penetration ability for kinetic energy projectiles, the projective structures have been continuously increasing in thickness and developing in the direction of composite-medium materials, resulting in increasing complexity in testing the overload characteristics of the detonation control system. Addressing this difficulty, this paper analyses the range test data of the high-speed deep penetration of the composite-medium thick target. It is found that the overload characteristics has the long pulse width and multiple overload peaks, which is quite different from penetrating the single-medium target. Taking the overload characteristics of the detonation control system when penetrating composite-medium thick targets as the starting point, the influence of the thickness of the medium layer on overload characteristics is analysed, based on the deep penetration overload theoretical model of composite-medium thick target. It is found that by changing the medium layer in the composite-medium thick target, the overload peak and pulse width can be better considered in the equivalence study of overload characteristics. The equivalence composite-medium thick target is designed by the FE simulation, the overload characteristics of double overload peaks and long pulse width in the range test are well simulated. The equivalence method of the overload characteristics of the detonation control system is formed based on the composite-medium thick target, and it can also provide technical support for the reliability design of the anti-thick detonation control system.
Numerical Simulation of Modular Charge Security under Different Drop Postures
Authors: Wu S , Yu Y G , Zhao Z Y , Wang Y Q , Liu C 
Published: December 2024

Abstract
The impact of an accidental drop of modular charge may inevitably cause the charge to fail. In order to deeply understand the safety of modular charge under drop impact conditions and promote the safety evaluation and structural design of modular charge, a dynamic finite element model of modular charge was established based on nonlinear finite element theory. The module charge drop test was simulated by using ANSYS/LS-DYNA software. A numerical simulation was performed to evaluate the influence of drop postures on the stress, strain and acceleration response of the modular charge. The stress, strain and acceleration data of the modular charge when it dropped from a height of 1.5m onto Q235 steel plate, with three drop postures: bottom-downward vertical drop, horizontal drop and a 45° inclined drop. Results show that the ranking of dropping postures in terms of risk of modular charge rupture from highest to lowest is: 45° inclined drop, horizontal drop, and vertical drop. Under the condition of 45° drop, the maximum stress and strain in the modular charge are observed, with the minimum acceleration and the longest time to reach peak values. Under all three drop postures, the safety risk areas are located at the bottom of the combustible cartridge. The bottom of the combustible cartridge is the first to rupture when the modular charge is dropped at a 45° angle. Therefore, in the subsequent research on the improvement of modular charge, the impact resistance of combustible cartridges should be focused on.
Propagation characteristics of explosion shock waves in air under different temperature and pressure conditions
Authors: Hang Peng , Wenjin Yao 
Published: December 2024

Abstract
In order to study the propagation characteristics of explosion shock waves in air under different temperature and pressure conditions, stress wave theory and detonation wave theory were first used to analyze the propagation characteristics of shock waves. Combined with numerical simulation results, the propagation characteristics of explosion shock waves were comprehensively analyzed and verified. The following conclusion was drawn: the higher the pressure, the larger the peak value of shock waves at the same spatial position, and the greater the specific impulse of shock waves, Shortening of shock wave propagation distance; The higher the temperature, the less the peak pressure changes at the same spatial position, the smaller the specific impulse of the shock wave, and the longer the propagation distance of the shock wave.
Effect of aluminum powder particle size on quasi-static pressure and temperature in confined space explosion of aluminized explosives
Authors: Liu Zheng , Nie Jianxin , Kan Runzhe , Guo Xueyong , Yan Shi 
Published: December 2024

Abstract
Aluminum powder particle size is a crucial parameter concerning the energy release of aluminized explosives. This study aimed to examine the effect of single aluminum powder particle size and particle size gradation on the explosive energy release characteristics of aluminized explosives in confined spaces by using a self-developed confined explosion experimental device. Aluminized explosive samples having aluminum powder particle sizes of 6, 24, and 43 μm and particle size gradation of 6/24/43 μm were tested for explosion parameters generated by an internal explosion. The results indicate that the quasistatic pressure of the measured aluminum powder samples decreased gradually with the increase of the particle size. The quasi-static pressure of the particle size gradation explosive samples was the largest, and the quasi-static pressure increased by 5.0%, 9.9%, and 12.0%, respectively, compared with a single particle size. The highest peak temperature was observed for the 6 μm particle size sample. However, the highest equilibrium temperature was obtained for the particle size gradation sample, indicating that particle size gradation promotes the reaction of aluminum powder in the afterburning stage; this helps maintain the temperature of a confined space for a certain duration and increase the energy release of the aluminized explosives.
Effect of water environment on penetration parameters of shaped rod jets
Authors: Cheng Yubo , Jiao Junjie , He Yong 
Published: December 2024

Abstract
This study conducts a comparative analysis of the influence of the water environment on the large conical angle rod jet, juxtaposed with its behavior in air. Utilizing the LS-DYNA finite element software, the research simulates and examines the operational dynamics of a rod jet under identical shaped charge configurations in both water and air environments. The findings indicate that the compressibility of water is significantly lower than that of air, leading to a more rapid deceleration of the penetrating body upon entry into the aqueous medium. This results in a pronounced increase in the counter-impact force exerted by the water on the rod, which, in turn, is transmitted rearward. This backward transmission of force diminishes the pressure within the central region of the penetrating body, effectively reducing the velocity gradient and promoting the continuity of its motion through water.
Research on the effect of thin tungsten patch on the fracture behaviour of steel shells under detonation
Authors: Guo Q S , Ma Y , Meng Y P , Zhang X M , Zhang J J , Fang Z , Wang C T 
Published: December 2024

Abstract
To achieve controlled fragmentation of the shell, a pre-control method was designed, which involved adhering high-impedance thin tungsten patches to the outer wall of the shell according to specific rules. Based on the transmission and reflection characteristics of shock waves at different interfaces, the effect of waves on shell fracture was analyzed, revealing that the shell at the gap between the patches fractured first. Through numerical simulation studies, it was found that adhering thin tungsten sheets externally could effectively control the fragmentation of the shell, with shear fracture being the prior mechanism for shell fragmentation. When using rectangular patches, there were fewer connected fragments, and the effective fragment generation rate reached 67.90%, higher compared to the other two patch methods. Comparison revealed that the effective length χ was directly proportional to the effective mass of the fragment when using a rectangular patch, and χ=1.3 resulted in a pure shear fracture mode, forming the most uniform fragments. The velocity distribution along the axial direction was consistent under different patches, with the highest fragment velocity occurring at a distance of 3/4 from the initiation point. When rhombus patches were used, the average fragment velocity was higher than that of the other two patch methods.
Experiments and numerical simulations on ceramic-metal composite targets penetrated by a 7.62 mm armour-piercing projectile
Authors: Liu Z D , Wang S , Han Z Q 
Published: December 2024

Abstract
In order to explore the protective performance of ceramic-metal fibre composite target plate, a lightweight composite target plate consisting of aramid cloth, silicon carbide ceramic, TC4 titanium alloy, and ultra-high molecular weight polyethylene fibre plate was designed. The effects of adhesive type, stacking sequence and delamination on the protective performance of the target plate were researched through the ballistic impact test on the protective target plate with 7.62mm armour-piercing bullets. The effect of thickness variation of ceramic metal on the protective properties of target plate was investigated by LS-DYNA finite element software. It was found that the bonding effect of silicon carbide ceramics with TC4 was better than that of AB adhesive when the silica gel was used as the bonding adhesive. When the ceramic metal thickness dimension is certain, the ceramic delamination will weaken the protective structure performance, and the performance of the metal plate as the back support of the ceramic layer is better than that of the ceramic covered before and after the metal layer. The energy efficiency of the ceramic-metal structure is optimal when the ratio of the thickness of silicon carbide ceramic to TC4 is 4.84:1 for a certain surface density.
Research on the Method of Calculating the Wear Extent of the Rocket Sled Slipper Based on Pin-on-Disk Tests
Authors: Zhu Xiao , Yan Hua-dong , Cheng Ming-can , Qu Xiao-ting 
Published: December 2024

Abstract
This paper carries out the pin-on-disc wear test on the wear characteristics of the slipper-rail material under different loads and different speeds, and the research results show that: with the increase of load, the wear extent increases, but the relationship between speed and wear extent is not single; through linear regression analysis method to fit the pin-on-disc test wear extent, we get the wear coefficient k = a + b(pv) + c(pv)
2 of the slipper material when mating with the U71Mn steel, where a = 2.604 x 10−5, b = 1.115 x 10−10, c = 4.944 x 10−16. Then, from the wear loss effect of the slipper, the formula for calculating the wear extent of the slipper was derived, and the wear thickness of the slipper was calculated when the sled was accelerated to 1700m/s in a project.
Necking Analysis of High-speed Penetrating Projectile against Reinforced Concrete
Authors: Chen B H , Zou H H , Meng L , Wang W G , Dai X H , Wang K H , Zhou G 
Published: December 2024

Abstract
The complexity of penetrating projectile’s structure is not adequately considered in existing research of penetration. Based on this actuality, high-speed reinforced concrete penetration experiment is conducted and necking at the front end of projectile’s shank is found to be the most significant phenomenon. Mindlin–Herrmann rod theory is adjusted with elastoplastic constitution and finite element method to be applied in penetration calculation. Cavity expansion theory is applied as the longitudinal and radial load estimation. The calculation results denote that both longitudinal and shear waves propagate along the projectile when penetration begins. The necking is achieved instantly during the first circulation of stress wave propagation and the uniaxial compression state at the shank’s front end makes this structure vulnerable of initial yielding. Mindlin–Herrmann rod theory successfully explains the origin and influence zone of necking, while the necking’s degree and radial contraction at projectile’s tail require further investigation.
Analysis of numerical calculation methods for oblique penetration of projectiles into concrete targets
Authors: Yan Liu , Danyong Wang , Yijiang Xue , Zhenming Qin , Huamin Jia , Zhenqiang Huang , Zhendong Gao 
Published: December 2024

Abstract
This article uses finite element software ANSYS/LS-DYNA to analyze the numerical simulation method of projectile oblique penetration into concrete targets. FEM method is commonly used for numerical simulation of projectile penetration into concrete targets, but there is a problem of large deformation of concrete when penetrating concrete targets obliquely, and FEM method is prone to mesh distortion. Based on the experimental results of oblique penetration of the projectile into concrete, this article uses FEM, SPH, and FEM-SPH numerical simulation methods to obtain the numerical simulation results of oblique penetration into concrete targets at different velocities and incident angles of the projectile. The results from the deflection angle of the projectile and the depth of the crater indicate that compared with using FEM and SPH methods separately, FEM-SPH method has higher consistency with experimental results in simulating the oblique penetration of the projectile into concrete.
Simulation Study on Output Characteristics of Pyrotechnic Devices in Deep Water Environment
Authors: Ma Hongliang , Xue Yuanyuan , Yin Guofu 
Published: December 2024

Abstract
In order to study the output characteristics and influencing factors of pyrotechnic devices for weapons and equipment in deep-water environments, a simulation model of the action process of the model separation bolt under water load was established, and the changes of separation velocity and displacement of the pyrotechnic device with different variables were calculated with propellant charge, water depth and load shape as variables. The results indicate that, With the increase of propellant charge, the separation velocity of the separation bolt gradually increased, and the maximum separation velocity rise rate increased. With the increase of water depth, the velocity attenuation accelerates with the decrease of velocity, and the maximum velocity at 10 m depth is 74 m/s larger than that at 5000 m depth, and the displacement at 3 ms is about 150 times. After 5 ms, the reduction of spherical, conical and cylindrical load velocity increased sequentially, and the decrease of cylindrical load speed was 10 times that of spherical shape.
Glide-extended Projectile with Rotating Wings for Launch Stress Analysis
Authors: Chen Jinquan , Wang Xugang 
Published: December 2024

Abstract
During the launch process of a glide-extended projectile, the rotating wings on its back will experience extremely high overloads. To meet the reliability requirements of the wings, it is necessary to design the wing shape reasonably and select the wing material appropriately. This paper conducts a stress simulation on a subsonic airfoil, optimizes the shape of the wing, reduces the maximum stress the wing experiences during launch, and verifies through simulation that the aerodynamic characteristics of the optimized wing meet the mission requirements. Subsequently, stress analysis is performed on wings made of four different materials, and aluminum alloy is ultimately selected as the wing material, followed by modal analysis.
Size effect analysis of projectile penetrating semi-infinite concrete target
Authors: Liu Zihan , Zhang Xianfeng , Liu Chuang , Deng Yuxuan , Hou Xianwei , Fang Yizhou 
Published: December 2024

Abstract
Accurately assessing the damage effects of deep-penetrating weapons is of great significance for promoting the development of large-caliber kinetic energy penetrator warheads and the design of engineering protection. To accurately predict the penetration depth of projectiles into semi-infinite concrete targets, this paper derives through rigorous dimensional analysis and similarity theory that the maximum coarse aggregate size not scaling with the scale ratio and the strain rate effect are among the factors preventing small-scale projectile penetration tests on concrete targets from being extrapolated to full-scale tests. Based on the cavity expansion theory, the predictive model for the penetration depth of projectiles into concrete is derived. The accuracy and generality of the established model are verified through 20 groups of experimental data under different conditions, with an average prediction error of about 6.7% and a maximum error not exceeding 20%. Comparative analysis with the Wiffen’s model, Forrestal’s model, Wu’s model, Y.Peng’s model, and Feng’s model demonstrates the superiority of the model established.