bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental investigation of breakup times of droplet under the action of shock wave
Authors: Zhao Jiaxing , Yue Yajun , Jiang Lin
Published: June 2023

In this paper, the morphological characteristics and breakup time of droplet under the action of shock wave were investigated experimentally. Morphological characteristics of droplet were captured by high-speed photography. By varying the diameter of droplets and taking the influence of the shock wave Mach number into consideration, eight tests were performed in the experiments. The experimental results showed that under the action of the shock wave, the droplet underwent two different stages: the deformation stage and the atomization stage. In the deformation stage, the droplet evolved from spherical shape to pineal shape under the action of accompanying airflow induced by shock wave. In the atomization stage, the growth of unstable wave on the surface of the droplet caused by the Rayleigh–Taylor instability was the main reason for the droplet to be atomized. The effects of initial diameter and shock Mach number on atomization time were analysed. The decrease of initial diameter and the increase of shock Mach number reduced the droplet atomization time. The Mach number played a dominant role in the breakup process of the droplet.
Study on ballistic performance of a spherical cylindrical ceramic armor structure
Authors: Wu H L , Miao C , Mu X M , Cui X Z , Yang Z Z , Lu R J , Dang W , Bai L H , Wu X
Published: June 2023

A new type of ceramic armor structure is designed by using spherical cylindrical ceramic splice plate as panel with metal steel frame applied, TC4 titanium alloy and 685 steel as back plate respectively in this paper. Ballistic test of spherical cylindrical ceramic armor structure was carried out by firing 14.5mm penetrator projectile with 14.5mm ballistic gun. Results show that: damage area of spherical cylindrical ceramic armor is smaller when the weight is lighter and the aftereffect damage is similar, and ballistic performance of spherical cylindrical ceramic armor structure is better than that of conventional ceramic composite structure, which has certain advantages in anti-multiple projectile capability; ballistic performance of armor structure with TC4 titanium alloy as back plate is better than that with 685 steel as back plate when area density is the same. Therefore, using spherical cylindrical ceramics can reduce influence of the edge area on ballistic performance of armor structure, making protective capacity of the whole armor structure plate tend to be consistent, and improve anti-multiple resistance of armor structure furtherly.
Ballistic performance study of multilayer Al2O3 ceramic-metal composite armor under strong confinement
Authors: Yin G X , Li W B , Huang X N , Zhang K B , Hong D , Chen J H
Published: June 2023

A multilayer constrained alumina ceramic metal composite armor is designed in this paper. The effect of interlayer steel thickness of alumina ceramic metal armor on penetration process of tungsten alloy armor piercing projectile is studied by the penetration test and finite element simulation. The results show that in the case of the same layer of ceramics and equal surface density, the thicker the thickness of the steel plate away from the impact surface is, the better the support of the metal plate to the sandwich ceramics is. It is beneficial to maintain the initial volume of ceramics and the better ballistic performance of armor. The ballistic performance of the armor structure in this paper is 26.38 % higher than that of the Q235 steel plate with equal density.
Research on measurement methods and sensor selection of rocket gas jet impact force
Authors: Zhang Zhi , Liu Zhipeng , Li Lingzhi , Jiang Lin
Published: June 2023

Based on a rocket launcher gas jet impact force measurement method, this paper designed an experiment to study the influence of different types of sensors on the test results. By comparing and analysing the data waveforms and amplitudes measured by the three sensors at different distances, the accuracy of the test results of each sensor is obtained. The test results show that, for the gas jet impact force measurement method introduced in this paper, the choice of the DYLY-107 S-type strain gauge force sensor can more accurately monitor the impact flow field and impact force amplitude.
Influence of explosion distance on the dynamic mechanical response of underground fortification
Authors: Lin Q D , Feng C , Gan Y D , Cheng P D , Jiao W J , Zhang Y L , Yuan J F
Published: June 2023

Many key military targets have been moved underground to improve the battlefield survivability. To study the influence of explosion distance on the dynamic mechanical response of underground fortification, the full-time numerical simulation is conducted based on the CDEM numerical method. First, four numerical simulations corresponding to different explosion distances are conducted. Then, the displacement characteristic of underground fortification and rock mass is analyzed. Finally, the fracture characteristic of underground fortification and rock mass is analyzed. The numerical results show that the damage degree of underground fortification and rock mass weakens with the increase of explosion distance. When the distance increases from 5 m to 20 m, the volume of rock entering the underground fortification decreases from 24.78 m3 to 0 m3. The time-history curve of crack ratio has the four-stage characteristic, and it increases rapidly during the explosion initiation process. As the explosion distance increases, the top concrete wall mainly undergoes tensile fracture.
Numerical simulation of the effect of the near-ground explosion of energetic materials on the shell of a vertical incinerator
Authors: Jin G R , Wang M R , Chen L , Zhang J W , He W D , Liao X
Published: June 2023

In order to study the effect of the near-ground explosion of energetic materials (EMs) on the shell of a vertical incinerator, the effect of different explosion heights of EMs of 90 g TNT on the incinerator shell with different exhaust gas outlet diameters was numerically simulated in three dimensions using AUTODYN software. The simulation results showed that the maximum von Mises equivalent stress (mis. stress) of the shell occurred at the upper edge of the incinerator exhaust gas outlet. Furthermore, the maximum mis. stress of the shell increased with the decrease of the height from the TNT explosion center to the bottom of the shell and the increase of the exhaust gas outlet diameter of the incinerator. Importantly, the existence of the incinerator exhaust gas outlet and the constraint of the shell increased the critical height with the near-ground explosion effect compared to that of the unconstrained open environment (157 mm). The exhaust gas outlet diameter of the incinerator increased from 80 mm to 160 mm, and the critical height with near-ground explosion effect increased from 180 mm to 250 mm. In the design and application of vertical incinerators, the effect range of near-ground explosion can be reduced by reducing the diameter of the shell exhaust gas outlet and filling the bottom surface with a certain height of shock wave attenuation material.
The velocity distribution of fragment from air part of cylindrical casing
Authors: Gao Yue-guang , Feng Shun-shan , Xiao Xiang , Hu Wenlong , Huang Qi
Published: June 2023

In some cylindrical casings, the non-explosive material or structure exists. The explosive charge is axially discontinuous, the propagation of detonation wave is also discontinuous, and the driving process of metal casing is diverse from continuous charge. If the non-explosive material or structure in the middle is regarded as air, it is called the cylindrical casing with air part in the middle. Due to the combined effects of rarefaction waves and the detonation wave generated by explosive charges on both sides, existing formulas of fragment velocities from cylindrical casing can neither accurately predict that from explosive charge part, nor predict that from the air part since the mass ratio of the explosive charge to the metal casing in the air part is 0. Adopt the method of simulation analysis, the cylindrical casing with air part in the middle was analyzed. A new formula was established to predict the fragment velocity of air part from cylindrical casing in the middle, which showed good agreement with the simulation results.
Effects of dynamic prestress on silicon carbide ceramic against long rod impact
Authors: Xu Wenlong , Qi Fangfang , Jia Shiyu , Ma Dong , Wang Cheng
Published: June 2023

It is well known that silicon carbide (SiC) ceramic is a pressure dependent material, where the compressive strength increases as the pressure increases. So, it is an effective way to improve the ballistic performance of SiC ceramic by introducing prestress on ceramics surface. In this paper, the concept of dynamic prestress on SiC ceramic by energetic materials was proposed. Five key factors, including the time of projectiles contact targets, velocity of the long rod projectiles (V
p), prestress rising stage time (T
r), prestress descent stage time (T
d) and peak pressure of prestress (P
k), were selected to investigate the effect of dynamic prestress on SiC ceramic targets against long rod impact. The effect of dynamic prestress on the ballistic performance of SiC ceramic were investigated, and the dynamic prestress path which can increase the protection capability of SiC ceramic was given. The results indicated that, in most cases, the ballistic performance of the dynamic prestressed SiC ceramic targets against long rod projectiles impact was improved. However, it was also revealed that not all dynamic prestressing can improve the ballistic performance of SiC ceramic targets. It will be benefit to the ballistic performance of SiC ceramic by controlling the prestress time to make sure the moment of the long rod projectile impacts the target in between T
2 and T
4. The sequence of influence degree of each factor on the erosion length of long rod projectile is the velocity of long rod projectiles (V
p), prestress descent stage time (T
d), peak pressure of prestress (P
k) and prestress rising stage time (T
r). The erosion length of long rod projectile decreases with the increase of V
p, and increases with the increase of prestress descent stage time (T
d), peak pressure of prestress (P
k) and prestress rising stage time (T
r).
Uncertain ballistic effects and reliability optimization design of ceramics composite armors
Authors: Shen Zhiwei , Tao Zhiguo , Li Jishan , Li Nan
Published: June 2023

The uncertain ballistic effects and reliability optimization design of the ceramics composite armors are investigated. Considering the material uncertainty, the ballistic penetration process is analyzed through simulation model. The effects interlayer SiC mass fraction and the matrix thickness gradient ratio are discussed. The optimal parameters of both material and structure are obtained through reliability design methods and verified through ballistic experiments. The results show that the standard deviation can be reduced when interlayer SiC mass fraction increases. The ballistic depth can be reduced by increasing the gradient ratio. Through optimization, the ballistic reliability of the ceramic composite armor is improved.
Structural and flow field analysis of an airfoil subjected to blast-impacted
Authors: Xiao Liangfeng , Zhou Lanwei
Published: June 2023

The shock wave from the explosion of the munition can cause severe damage to the aircraft structure, thereby affecting the aerodynamic performance of the aircraft. This paper aims to propose a Computational Fluid Dynamics (CFD) analysis for the aerodynamic behaviour of the wing after the damage and deformation caused by the impact load. To obtain the damaged deformed wing model for CFD analysis, the explosion damage process was calculated using LS-DYNA software, and the obtained structural deformed wing model was imported into the CFD solver for flow field calculation to obtain lift, drag, and moment coefficients and lift-to-drag ratio. The lift of the damage-deformed wing model decreases due to the destruction of the pressure distribution of the damage-deformed wing model. The lift-to-drag ratio is also affected by shock loading, with smaller values at all considered angles of attack. Similarly, the damage deformed wing model has larger moment coefficients at angles of attack less than 19.5°.
Deformation behavior of aluminum alloy tubes during wire-explosion impact forming
Authors: Zheng Q L , Yan J M , Cui J , Liu H Y , An X J , Dong J X , Dong M
Published: June 2023

Wire-explosion impact forming (WEIF) is a forming process based on a coupled effect of gaseous, liquid, and solid media, and the experimental work alone is not sufficient to properly show this complex process. To understand the plastic deformation behavior of workpiece under the action of shockwave load, WEIF of AA5052 tubes were simulated in LS-DYNA by considering the fluid/structure interactions. Then, the stress, displacement, velocity, and thickness of AA5052 tubes during the forming process were quantitatively analyzed, and the generation and propagation of shock waves were demonstrated. Finally, the numerical simulation results were effectively verified by the experimental results.
Propagation characteristics of shock wave in wire explosive impact forming process
Authors: Zheng Q L , Yan J M , Cui J , Li J Q , Xu X D , Zhang X F
Published: June 2023

The theoretical analysis and numerical simulation are combined to explore the generation mechanism and propagation characteristics of the shock wave in WEIF process. The results show that with the increase of linear density of deposition energy, the propagation distance of shock wave in the same time is longer; as the propagation distance of shock wave increases, the propagation velocity on the wave front gradually decreases. In the early stage of the electric explosion of the metal wire, the shape of the shock wave generated is the expansion and evolution of the cylindrical wire source,and the pressure wave generated by the electric explosion of the metal wire is close to an ellipsoid. Since the expansion of the shock wave is radioactive, its shape gradually homogenizes to a sphere.
Study of blunt impact effects of rifle bullet penetrating the SiC/UHMWPE armor covered human torso
Authors: liang Xu , Yaoke Wen , Aijun Chen
Published: June 2023

To study the behind armor blunt trauma (BABT), a finite element model of a 5.8 mm rifle bullet penetrating the SiC/UHMWPE armor covered human torso was established. The human torso model comprises internal organs (heart, lung, liver, and stomach), skeleton (sternum, ribs, and spine), and muscle. It is assumed that the skeleton and muscle is linear elastic, and all internal organs are viscoelastic and hyperelastic. The impact response of a rifle bullet penetrating a human target with bulletproof armor at a speed of 900m/s is numerically simulated. The deformation data of bullet and body armor were obtained. In addition, the von Mises stresses of muscle, skeleton, and internal organs were analyzed. The numerical model provides an effective method for studying BABT and the improvement of bulletproof armor.
A Numerical Study on Projectile Penetration into Underwater Torpedo Warhead
Authors: Ding Chufan , Chen Bin , Li Weibing , Gao Dacheng , Chen Yaohui , Feng Jun
Published: June 2023

Underwater torpedo interception could be conducted by shell perforation or even warhead impact detonation with high speed projectiles. This work deals with the projectile water entry and sequent penetration into underwater torpedo whereby both aluminium shell perforation and explosive detonation are numerically studied. The water entry model and aluminum impact model are validated against test data for underwater aluminum shell penetration. Targets are located under water with 20 cm depth where aluminium shells for penetration are air-back while the impact detonation model has explosives inside shell. Four kinds of different nose shape tungsten projectiles are used for penetration simulation, revealing that ogival nose projectiles have superior performance for both shell perforation as well as detonation than conical nose projectiles. Numerical predictions shed some light on nose shape optimization design of high velocity projectile against torpedoes.
Research on Anti-ballistic Mechanism and Numerical Simulation of Biomimetic Composite
Authors: Shuhu Li , Juncong Liu , Yusong Huang , Aiyun Liu , Jingli Xu , Wenfang Xing , Huazhen Wei , Ronghui Wang
Published: June 2023

The multilayer toughening conch-nacre structure biomimetic composite consisted of alternant thin-hard layer ceramic and flexible resin matrix composite was prepared and designed, and its ballistic mechanism was studied. The testing results showed the damage effects of biomimetic composite were mitigated evidently while shielded the impact effectively in contrast with the smash of the common armour ceramic when encountered ballistic impact. The ballistic performances of the resin matrix composite and biomimetic composite were simulated by using ANSYS/LS-DYNA, material models of the resin matrix composite and biomimetic composite were expatiated. The calculation results were in accorded with testing result very well. This research methods and conclusions were valuable for engineering applications.
Difference Analysis of Different Explosion Load Simulation Methods Based on LS-DYNA
Authors: Wang L J , Wang T , Cheng Sh , Yin W J , Liao Z
Published: June 2023

LS-DYNA provides a variety of different explosion load simulation methods, which are widely used in the field of explosion shock. Compared with the direct application of explosion load on the structural surface, the simulation method of establishing the air domain is more complex, but it can reproduce the evolution process of the explosion flow field and consider the interaction between the shock wave and the structure. The simulation results are more consistent with the actual situation. In this paper, the four commonly used explosion load simulation methods in LS-DYNA software are compared and analyzed, and the sensitivity analysis of grid size is carried out. The differences in the results of the four explosion load simulation methods under typical explosion conditions are compared and analyzed from the aspects of explosion shock wave waveform, arrival time, overpressure peak and specific impulse. The analysis results show that the proportional detonation distance of 0.8 m/kg1/3 is the boundary point of grid sensitivity ; under the same grid size, different explosion load simulation methods have little effect on shock wave arrival time, but have obvious influence on overpressure peak value and specific impulse. It is critical to reasonably select the termination time of the low-dimensional model when using the mapping method ; method 1 and method 2 are preferred for simulation without considering the computational cost or small model size. When the model is large, method 3 and method 4 should be preferred to improve the computational efficiency.
Study on Radial Distribution of Fragments Velocity of D-shaped Fragmentation Warhead
Authors: Liu W L , Jiang J W , Li M , Yin G , Sun X
Published: June 2023

For the asymmetric D-shaped fragmentation warhead with high charging coefficient and space efficiency, we simulate the driving process of fragments under typical eccentric initiation by using the fluid-structure interaction algorithm, and obtained the change rule of the fragment velocity radial distribution with the central angel, the thickness and material of the upper end cap. The results of numerical simulation show that the fragment velocity of D-shaped warhead increases gradually from the reverse to the forward direction, the velocity of fragment in forward direction increases by about 10% under single-point eccentric initiation compared with the cylindrical casing under center initiation, and the fragment velocity under double-point eccentric initiations is higher than single-point eccentric initiation; The initial velocity of the fragment has a positive correlation with the thickness and density parameters of the upper end cap; the mass of the warhead and the total kinetic energy of the fragments in the forward area increase with the increase of the central angle, but their ratio increases first and then decreases with the increase of the central angle. The results can be applied to structural optimization design and power evaluation of the warhead.
Study on Impact Response of Typical Powder in Confined Space
Authors: Jin Wen , Men JianBin , Jiang JianWei , Li HaiFeng
Published: June 2023

A novel experiment combined with simulation method was developed to investigate the impact response of the powder which was put into a submunition. The powder’s material model parameter was determined by powder mechanical test. Machete hammer test platform was built to apply 20kG~30kG load to the submunition. The submunition was recycled and the powder state was observed after impacting by the Machete hammer. What’s more, nonlinear dynamics analysis software (AUTODYN) was applied to clarify the impact response and density distribution process of the powder. A verified ideal model was carried out to simulate the explosive impact loading process of the submunition. The powder density distribution was reconstructed by MATLAB. Meanwhile, a law of the powder’s centroid with the over loading was successfully established based on the simulation data. The results shows that the peak value of the impact loading has a linear relationship with the relative offset of the centroid position.
Influence of the Fragment Velocity Gradient on the Hit Density under the Dynamic Condition
Authors: Shujie Cheng , Zhengfeng Liang , Xijun Ruan , Runyuan Miao , Haijun Wu
Published: June 2023

The influence of the fragment velocity gradient on the hit density under the dynamic missile-target meeting condition is discussed using theoretical analysis, and the analytical relationship is obtained. The results show that under static explosion conditions, the fragment hit density is independent of the velocity gradient of the fragment group. Under dynamic conditions, the distribution bandwidth of the fragments on the target becomes wider with the increase of the velocity of the missile-target meeting and the velocity gradient of the fragment group, and the increase of the fragment bandwidth decreases the fragment hit density.
Effects of weak connecting structure on penetration performance of free-flight rocket
Authors: Yu Wanqian , Gao Hongchao , Guo Tengfei , Liu Ji’an , Gu Wei
Published: June 2023

The strength of connection between the rocket engine and the warhead has a certain relationship with the warhead’s ballistic characteristics and structural response. In this paper, the effects of weak connecting structure on the penetration performance of the free-flight (unguided) rockets is studied by numerical simulation and experiment. The oblique penetration of free-flight rockets with different connecting structures into armour plates is numerically simulated, the rockets’ deflection in the penetration process is analysed, and the effects of the weak connecting structure on the warhead’s structural integrity are evaluated according to the deformation of the warhead tail. The oblique penetration test of free-flight rocket is designed, and the simulation results under low impact velocities are verified. The research shows that the influence of the length of the weak connecting structure on the tail deformation of the warhead varies at different impact velocities. It is better to use direct connection between the engine and the warhead at high impact velocities, and the weak connecting structure performs better at low impact velocities.
Research on ballistic performance and numerical simulation technology of Si3N4 ceramic materials
Authors: Wang Wanying , Liu Jingang , Zhou Haiqi , Mu Zeyuan , Yan Jie , Su Zizhou , Wang Yue
Published: June 2023

Ceramic materials are widely used in the field of armor protection because of high hardness and low-density. In order to research the ballistic performance of Si3N4 ceramic and evaluate the penetration effect, the DOP test against the 12.7 mm API was carried out. The results show that the protection coefficient is in the range of 1.85-4.26, and thickness coefficient is in the range of 1.85-4.26. On this basis, the numerical simulation technology of Si3N4 ceramic composite armor is studied by using LS-Dyna software. The accuracy of the finite element model is verified by comparing the test result. It can guide significance for the use of Si3N4 ceramic in the field of armor protection.
Calculation and optimization of lethal power of controlled fragmentation warheads with diamond notch grid
Authors: Li Guanqun , Li Xiangdong , Zhou Lanwei , Ji Yangziyi
Published: June 2023

The lethal power is the critical design index of the explosive warhead, mainly related to the number and mass of fragments formed by the warhead case. For the controlled fragmentation warhead case containing notches, the notch depth and spacing are the main factors affecting the fragment formation. This paper analyzes the influence of the notch number and depth on the network of fracture trajectories. It establishes a calculation model for the mass and number of fragments of warheads with various groove parameters. The lethal radius is obtained from the calculated fragment data and compared with the results of the experimental data and numerical simulation. The paper uses the genetic algorithm to obtain the optimal solution under various design variables, taking the groove depth and the number of circumferential grooves as the design variables and the lethal radius as the optimization objective. The optimized result is higher than without optimization.
Research on the ability of artillery-launched laser beam-guided artillery projectiles to counter high-speed dive and large-wall thickness guided munitions
Authors: Cheng Guang-wei , Chen Chen , Wang Hua-ting
Published: June 2023

Aiming at the typical high-speed dive high-thickness guided munitions air attack problem, according to the shooting characteristics and typical target characteristics of a vehicle-mounted medium-caliber anti-aircraft gun compatible with laser beam-guided projectiles, the impact of the long-distance shooting of artillery-guided projectiles on the hit probability was analyzed. The main factors are the simulation calculation of the shooting probability of the weapon system; the plan of the shaped warhead for the anti-high-speed dive with large wall thickness guided munitions is proposed, and its LS-DYNA simulation model is established. The K-level damage of the thick wall thickness guided munition provides a technical approach for the future anti-high-speed dive thick wall thickness guided munition, as well as CRAM (anti-artillery, rocket and mortar shells).
Influence of Initiation Diameter on Formation of Collinear EFP with Fins from Warhead with Double Layer Liners
Authors: Zhang Kun , Zhao Chang-xiao , Ji Chong , Tu Wan-peng , Xin Wang , Liu Kai
Published: June 2023

To improve the aerodynamic performance of collinear EFP from warhead with double layer liners, the forming process of collinear EFP with fins and the effect of the initiation diameter on the formation of collinear EFP with fins under four-point initiation was analyzed by using LS-DYNA software. The results showed that it could form symmetrical and uniform fins at the tail of collinear EFP by using multi-point initiation, which effectively improved the aerodynamic performance of collinear EFP. The impact of initiation diameter on forming parameters of collinear EFP with fins was mainly reflected in the shape parameters but had little influence on the velocity. The initiation diameter was bigger, the length-diameter ratio γ and wingspan-diameter ratio β of the front EFP increased linearly while the wingspan and wingspan-diameter ratio β of the rear EFP decreases, and the reduction rate decreased gradually.
Numerical Simulation of Hypervelocity Launch Process of Cased Telescoped Ammunition Armor-piercing Projectile
Authors: Guo J T , Zhang X W
Published: June 2023

In order to study the interior ballistic characteristics of cased telescoped ammunition (CTA) armor-piercing projectile in the hypervelocity launch process, in this paper, based on the secondary ignition and propellant combustion technology, the zero-dimensional internal ballistic model of CTA is established. At the same time, in order to improve the lightweight of CTA and the energy utilization rate of the launch process, combustible cartridge materials are applied to the structure of cased telescoped ammunition. Numerical simulation of 105 mm CTA grenade shooting experiment has verified its correctness. On this basis, the internal ballistic process of 105 mm CTA armor-piercing projectile with semi-combustible cartridge is predicted and analyzed. When main charge propellant weight is 6 kg, the maximum pressure is 569.5 MPa and the muzzle velocity can reach 1702 m/s.
From the development of shipborne laser weapon of U.S. navy to analyze the military requirements and countermeasures of navy
Authors: Zhang Hetian , Zeng Yaqin , Sun Shiya
Published: June 2023

In recent years, U.S. navy is exposing frequently some tests and development about shipborne laser weapon, which have attracted aboard attention and passionate discussion. In this paper, the review on shipborne laser weapon of U.S. navy from the 21th century is summed up. Some oppugns or baffles are also analyzed in this process. The meaning on developing shipborne laser weapon is discussed more deeply. Furthermore, some advices are put forward.
Three-dimensional magneto-thermo-mechanical coupling analysis with the influence of velocity skin effect
Authors: Wang Dexiang , Li Baoming , Li Haiyuan
Published: June 2023

In this paper, the three-dimensional magnetic diffusion governing equations of an electromagnetic railgun are derived based on Maxwell’s equations and coupled with the energy equations. The finite element method is used to calculate the current density, temperature, and electromagnetic force distribution for armature velocities of 0, 200, 600, and 1200 m/s. The results show that there is a current concentration phenomenon on the rail’s inner surface and the trailing edge of the contact interface; the temperature rise of the rail along the moving direction of the armature tends to decrease, and ablation occurs at the corner of the moving armature’s trailing edge. An increase in the velocity of armature movement results in an increase in the electromagnetic forces on the armature and contact surface. This model can effectively represent the variation of each physical quantity with velocity and provide direction for the optimal design of the rail and armature.
A Review of the Computational Investigation of Three-Dimensional Transient Magneto-Thermal Coupling Characteristics of Electromagnetic Railgun Armature and Rail in High-Speed Sliding Electrical Contact
Authors: Gu Benfeng , Yang Chunxia
Published: June 2023

In order to investigate the dynamic process of electromagnetic field distribution, temperature change and the deformation during the launching process of electromagnetic railgun. It is necessary to conduct a three-dimensional coupled electromagnetic-temperature-structure analysis of the rail and armature, which requires the establishment of the corresponding multi-physics field model and the use of appropriate software and algorithms to complete the relevant simulation calculation and solution results. Based on this, this paper summarizes the current domestic and foreign research methods for multi-physics field characteristics under sliding electrical contact conditions, analyses the advantages and disadvantages of each method, and focuses on the updates of the three-dimensional finite element program EMAP3D based on Lagrangian description and the advantages of multi-field coupling. Finally, several considerations and operable spaces for multi-physics field coupling simulation are summarized to provide technical support for subsequent studies on multi-physics field characteristics for high-speed sliding electrical contact condition.
A review of static/quasi-static calculations of Electromagnetic-thermal coupling sliding electrical contact characteristics of armature and rails
Authors: Xu Gang
Published: June 2023

The analysis of the sliding electrical contact characteristics between the armature and rails is an important research area for electromagnetic railguns. In this paper, a sliding electrical contact model considering non-ideal factors is introduced, the magneto-thermal coupling characteristics of the contact interface are summarized, and the current and temperature distribution characteristics are outlined. In the end, measures that can be taken to improve the contact performance are presented in terms of armature rail material selection and structural optimization.
Study on discharge characteristics of pulsed power module under the condition of discharge short circuit fault
Authors: Liu Jian , Wang Zhang-fei , Minhao-Zhong  , Li Bao-ming
Published: June 2023

Efficiency and safety are key factors that must be emphasized in pulsed power applications. The discharge characteristics of pulsed power supply directly determine the performance of the railgun. This paper conducts a research on short-circuit faults in transmission coaxial cables of pulsed power supply. In order to study the effect of short-circuit fault on the discharge characteristics of pulsed power supply and system efficiency,a pulse-forming network with cable short-circuit failure and dynamic railgun model are established in the paper. The effect of short-circuit fault on peak current is discussed by simulation. The results show that the short-circuit fault currents are all higher than the currents under normal conditions, and the closer the short-circuit location is to the power supply side, the higher the peak value of current is. In some extreme case, the peak fault current exceeds 1.5 times the normal, which requires consideration of short-circuit fault protection measures, such as the addition of a DC circuit breakers.
Timing control of impulse self balancing latch opening of expansion wave gun
Authors: Zheng Dou , Hongjin Wang , Junmou Qiao , Yongcun Wang
Published: June 2023

Aiming at the problem of accurate latch opening control of expansion wave gun automatic gun, the mathematical model of accurate latch opening time is established, the travel curve of projectile and expansion wave, the velocity curve of projectile and expansion wave are studied, and the occurrence time of expansion wave and the time close to projectile are simulated and analyzed; The time-space evolution relationship between expansion wave velocity and local sound velocity, projectile velocity and gas velocity is simulated; The average pressure time curve and chamber resultant force curve of the two launch modes are compared and analyzed. After the projectile moves for 2.7ms, the chamber pressure and chamber resultant force of expansion wave launch are significantly reduced; The dynamic model of inertial latch opening is established; The changes of projectile initial velocity and recoil force under different latch opening times are studied. The test shows that the recoil force and recoil distance are greatly reduced when the projectile initial velocity decreases very weakly, which shows that the simulation calculation of latch opening time is accurate.
Parametric analysis and design of the initial contact state of a 400kA pulsed current C-armature
Authors: Liu Jingang , Jiang Yi , Su Zizhou , Ye Weisheng , Zhang Tao , Wang Wanying
Published: June 2023

As a key component of an electromagnetic rail launcher, the armature plays a vital role in the performance of the electromagnetic launch. In order to solve the contact area and structural design problems of C-type armatures under large pulse current conditions, the material and initial contact state of a certain calibre C-type armature are studied, and the initial structural parameters of C-type armatures under 400kA through-current capacity and four times the calibre loading position constraints are analysed and calculated, together with the contact characteristics of armatures made of 6061-T6 and 7075-T6 aluminium alloys, to form At the same time, the parametric design of the C-type armature was carried out on the basis of the initial structural parameters, and the variation laws of contact stress, contact deformation, preload force and contact area were studied for different armature lengths, armature tail thickness, armature throat thickness and armature head height, with the encore law, contact area and plastic deformation stress as The structural dimensions of the C-type armature for a 400 kA pulse current are determined, providing a direction for the structural optimisation of subsequent large pulse current C-type armatures.
Design and Research of Missile launcher Drive System for Anti-aircraft Gun and Missile Weapon System
Authors: Wang Yan , Zhou Jia-yong , Meng Xiao-jing , Lei Kai-wen
Published: June 2023

Aiming at the problems of large size and weight of electric cylinder, low efficiency and large pressure fluctuation of centralized hydraulic drive system, a drive system of anti-aircraft gun and missile weapon system based on electro-hydrostatic actuator is designed. The working principle of the hydraulic system of electro-hydrostatic actuator is discussed, its components are selected and designed, the micro cartridge hydraulic control check valve is designed and the electro-hydrostatic actuator is analyzed and integrated structure is designed;The simulation model is established by AMEsim software. The simulation results show that the electro-hydrostatic actuator can move the missile driving device to the highest position within 2s, meet the working requirements, and have certain guiding significance for the research and development of missile launcher driving.
Development status of anti UAV swarm and analysis of new defense system
Authors: Tianfeng Fan , Xiaojing Meng , Chi Zhang
Published: June 2023

UAV swarm is gradually becoming a comprehensive new weapon platform integrating electronic countermeasure, information attack and defense and firepower attack. It has become an important form of future combat, and also gave birth to the rapid development of anti UAV swarm system. Aiming at the problem that UAV is developing rapidly and becoming an important threat in the battlefield, the characteristics of typical UAV swarm system level targets are analyzed. The main means of counteracting UAV swarm, such as air defense missile, anti-aircraft gun / missile gun combination, high-energy laser and high-power microwave, are studied, and the counteraction performance is compared and analyzed. A new air anti UAV interception system based on UAV mounted micro recoil automatic gun is proposed, and the architecture, combat concept and process, key technologies and innovations involved are studied, which provides a technical reference for strengthening the ability of anti UAV system.
Application research of gun servo system based on Stribeck friction model
Authors: Pan Jun , Dai Pu , Ma Qing , Liu Miao , Yang Zhizhong , Lei Shuyao
Published: June 2023

The gun servo system has strong friction resistance moment. The traditional solution is to reduce the influence of friction disturbance on system control through speed closed-loop. The disadvantage of this method is that the control accuracy of the system is not high due to the lag effect of feedback. To solve this problem, based on the analysis of the composition and working principle of the gun servo system, the friction data of the servo system is obtained through the test, the Stribeck friction model of the system is identified by the method of curve fitting, and the disturbance of the friction torque is compensated and controlled by the control method of feedforward compensation based on disturbance. The simulation results show that this method has good compensation and control ability for the disturbance of friction resistance moment. After using this method, the dynamic tracking accuracy and control performance of the system are greatly improved.
Status and Prospect of Land-based Delivery Platform Technology for Artillery Weapons
Authors: Tianfeng Fan , Hongqing Liu , Cheng Huang , Zheng Wang
Published: June 2023

Land-based delivery platform technology for artillery weapons is a comprehensive technology to study the adaptability of artillery weapon and land-based delivery platform, and its function is to is to provide transportation and loading platform for artillery and realize tactical mobility and battle mobility of artillery. This paper reviews the important technical progress of China’s artillery weapons in land-based delivery platform technology, contrasts and analyses the research progress at home and abroad, and outlooks the development trend and countermeasures in the field of land-based delivery platform technology for China’s artillery weapons.
Analysis and experimental study on dynamic characteristics of key joint of helicopter gun
Authors: Xiao-ke Gao
Published: June 2023

The dynamic characteristics of the key combined structure of helicopter and helicopter gun have an important impact on the matching between helicopter and helicopter gun. In the research process of impact load transmission, firing accuracy and reliability, the characteristics of the joint is an important factor to be considered in structural modelling, analysis and optimization. In this paper, the dynamic characteristics of the joint of the gun seat ring, bracket and trunnion are studied by combining experimental and theoretical analysis. Through the modal analysis of the structure, the natural frequencies and vibration modes of the key joint are obtained, which provides a theoretical and experimental basis for the matching of the impact load and the natural characteristics of the structure and the optimization of the impact response in the firing process of the gun.
Launching Process Analysis of Aircraft Gun with Closed Type Gas Reflection Device
Authors: Luo D , He F , Dai J S , Wang M S , Su X P , Lin S Y
Published: June 2023

Recoil reduction is one of the most important issues for the design of aircraft gun. Traditional approaches for this purpose will produce back-blast, which constitutes a hazard to fighter planes or attack helicopters. This paper presents a closed type gas reflection device for the aircraft gun aiming to reduce the recoil force without ejecting the propellant gas rearward. The launching process is modeled by coupling the classical interior ballistic model and the flow equations for the closed type gas reflection device. The fourth order Runge-Kutta method is adopted to solve the modified interior ballistic model to obtain the recoil efficiency of the closed type gas reflection device. On this basis, effects of various parameters on the recoil efficiency and muzzle velocity are studied systematically. Finally, shooting experiments are carried out upon a 30mm caliber aircraft gun. The simulated results agree well with the experiment ones. The results show that, by using the closed type gas reflection device, the recoil efficiency of 26.01% is attained without ejecting the propellant gas rearward, nor decreasing the muzzle velocity dramatically.
Research on the Stiffness Characteristics of the Rotary Structure of the Cannon
Authors: Shen Y L , Liu B , Liu D , Wang K Z
Published: June 2023

With the increasing requirements for the lightweight of the cannon, it is necessary to design the corresponding structure according to the specific load-bearing form of the cannon to ensure that the purpose of weight reduction can be achieved on the premise of meeting a certain rigidity. In this paper, for the cannon bracket, its structural form is simplified as a disk and double arms, and four characteristic variables of disk thickness, inclined length, straight arm thickness and curved arm thickness are obtained by extracting characteristic dimensions. According to the previous design experience, the feature size scheme design table is obtained. Models with different feature sizes were simulated and analyzed by the control variable method, and the effects of different feature sizes on the structural stiffness were explored. After analysis, it is found that the increase of the thickness of the disk, the decrease of the inclined length, and the increase of the wall thickness can improve the rigidity of the structure. And under the same thickness, the curved arm has better torsional stiffness than the straight arm, which can be increased by 15.2% on average. While the rigidity is improved, the requirements of light weight are realized. It provides a reference for the stiffness design of the double-arm structure that mainly bears the rotational torque.
Analysis of the acceleration of the multi-level vibration of the tank as firing
Authors: Liu J , Xu H Y , Heng G
Published: June 2023

Aiming at the system level vibration problem caused by the strong impact load during the tank firing, the tank is divided into several levels according to the vibration transmission path, such as barrel, cradle, turret, seat ring, car body and wheel. The multi-level vibration response characteristics of the tank during firing are obtained by arranging acceleration sensors at the typical positions of each level. Based on the time domain analysis method, the vibration acceleration at the positions of cradle, turret, seat ring, car body and wheel is analyzed, and the pulse amplitude and pulse time of vibration acceleration at each level are obtained. The analysis shows that under the action of firing load, the acceleration amplitude of muzzle, cradle, turret, seat ring, vehicle body and wheel decreases in turn. And the peak acceleration at the muzzle position is the largest, about 1400g, and the peak acceleration at the wheel position is the smallest, about 0.6g. The results will provide support for obtaining the multi-level vibration characteristics of the tank under the fire load and revealing the vibration transmission law of the tank under the fire load.
key technology and application of gun agile optimization design based on dynamic simulation
Authors: Xu Y F , Gu B , Shan C L , Liu P K
Published: June 2023

The new generation of artillery equipment is showing the development trend of lightweight, long-range, intelligent et al. However, the traditional development mode based on physical prototype test cannot meet these needs of equipment development. In the development, there are some problems, such as lack of systematic guidance in the overall design scheme, low degree of digitalization and parameterization of the model, and long period of serial iterative development, which need to be solved by optimization design. Parametric modeling technology, hard point driven template model technology and structural optimization design technology are briefly introduced, which are the foundation of equipment optimization design. These key technologies, combined with the overall scheme design, chassis system design and ammunition loading timing optimization design of a large-caliber tracked self-propelled gun, showing the basic development route of artillery performance improvement. The optimization design of artillery type equipment are summarized in recent years, which provide reference for other similar work.