bluuebunny/crossref_metadata_2025 huggingface dataset:
Rapid Coupling Analysis Model of Thermal Protection and Thermal Control for Electronic Equipment Cabin of High Speed Vehicles
Authors: Ma Fuqiang , Wang Feng , Wang Sheng , Li Xianglin , Li Yuan
Published: December 2024

In view of the serious problem of aerothermal “penetration” effect and equipment thermal accumulation effect in the electronic equipment cabin under long endurance and high speed flight conditions, this paper establishes thermal network models for thermal protection analysis and thermal control analysis based on lumped parameter principle, and verifies the validity of the thermal network models. Combined with thermal protection analysis model and thermal control analysis model, the thermal network model for coupling analysis of thermal protection and thermal control of electronic equipment cabin is established. And the necessity of establishing the coupling analysis model of thermal protection and thermal control is demonstrated. The thermal network model for coupling analysis of thermal protection and thermal control established in this paper takes only tens of seconds to analyse a single condition, and can well meet the requirements of calculation accuracy and calculation speed in the scheme stage of the high-speed vehicle. The research results are of great significance for the rapid iterative design of thermal management scheme in the scheme stage of high-speed vehicles.
Simulation of High Gradient Couette Flow in Narrow Gap Between Slipper and Rail on High Speed Rocket Sled
Authors: Zhang Chenhui , Li Xin , Pang Chao , Yang Yang
Published: December 2024

In order to study the flow problem inside the narrow gap of rocket sled slipper and rail, shock wave theory, supersonic boundary layer theory, and Couette flow theory were analyzed, and boundary layer thickness, velocity type, and temperature type formulas were obtained. By simulating the rocket sled slipper and rail model, flow characteristics were obtained at different Mach numbers. Research has shown that: (1) After the airflow enters the narrow gap between the slipper and the rail, a supersonic boundary layer is formed on the upper and lower walls of the leading edge, and converges at a certain point in the narrow gap. The thickness of the upper wall boundary layer is greater than that of the lower wall. As the Mach number increases, the thickness of the boundary layer slightly increases and the intersection point moves forward; (2) The velocity gradient and temperature gradient inside the upper and lower wall boundary layers are relatively large, while the velocity gradient and temperature gradient in the middle part of the narrow gap flow field are relatively small. As the Mach number increases, the velocity gradient on the lower wall increases, the velocity gradient on the upper wall decreases, and the temperature in the gap gradually increases; (3) The upper and lower velocity profiles of Couette flow are roughly symmetrically distributed around the matching point. The velocity gradient is large near the wall, but smaller than that of the leading edge boundary layer. The velocity of the middle section of the flow is lower than that of the middle section of the flow in the front of the narrow gap. The heat flux of Couette flow increases with the increase of Mach number, with a larger temperature gradient near the wall and a more uniform temperature distribution near the middle of the narrow gap.
Numerical investigation of the multi-physics coupling effect of supersonic projectile on the cross section of terminal ballistics
Authors: Shen Lingnan , Yang Ziyu , Chen Ding , Sun Haiyang
Published: December 2024

This study investigates the multiphysics effects the shock waves from the supersonic projectile on the cross section of its terminal ballistics, and this purpose is to effectively extract attitude information of projectiles in terminal ballistics。Firstly, the acoustic effects are used to study the propagation and attenuation laws of shock waves on the terminal ballistic plane, comparing the spectral characteristics of acoustic pressure signals and photoelectric signals; Secondly, through numerical simulations using COMSOL, the study analyses shock wave attenuation, refractive index changes, and pressure distribution at different Mach numbers. Results show that shock waves significantly affect the refractive index, which can be effectively detected using optical methods. The proposed method demonstrates improved accuracy over conventional techniques, particularly in capturing critical flight parameters of supersonic projectiles. This research lays the groundwork for developing advanced measurement techniques for hypersonic weapon systems, addressing current limitations in projectile detection and measurement accuracy.
Design of transient thin film heat flux sensor based on the transverse thermoelectric effect
Authors: Liu Songhan , Zhao Jiaxing , Wan Chen , Huang Yuxiang , Liu Zhipeng
Published: December 2024

Accurate heat flux measurement is critical for evaluating thermobaric elastic thermal damage, and acquiring heat flux at the time of explosion provides an important foundation for estimating damage sverity. To suit the test requirement, a transient thin film heat flux sensor (THFS) using the transverse thermoelectric effect was developed. The THFS offers the benefits of small size and rapid reaction time. The sensitive element of the THFS is made up of a lead telluride (PbTe) film, a sapphire substrate, gold electrodes, and a heat-absorbing coating. PbTe films were created on the sapphire surface using magnetron sputtering, and gold electrodes were grown on both sides of the film by electron beam evaporation. The THFS, which was evaluated for static and dynamic performance throughout a laser-generated heat flux range of 1.2-3.8 MW/m2, had its static performance test results revealing an excellent linear connection between the THFS response voltage and the laser applied heat flux, with a sensitivity of 1.40 μV/(kW/m2). The dynamic performance test, which demonstrated that THFS can get a full heat flux curve under the excitation of a low pulse width heat flux signal, showed a measured time constant of 10 μs. The novel heat flux sensor is intended for high reaction speed and dependability, providing a dependable new approach for measuring heat flux during thermobaric bomb explosions.
Research on the Spin-Stabilized Projectile Spin Drift of Recoilless rifle with Rifling
Authors: Ding Feng , Tao Gang , Wen Peng , Jiang Zhonghui , Ding Guipeng , Pang Chunqiao
Published: December 2024

The recoilless rifle with rifled barrels is a type of high-powered individual infantry weapon, boasting an effective firing range of up to 3,000 meters. Experiments have found that with the increase of firing range, the spin drift of spin-stabilized projectiles fired by recoilless rifle has seriously affected their shooting accuracy. In this paper, we study the influence of the drift effect of spin-stabilized projectiles on the impact point in the Recoilless rifle. The aerodynamic parameters of spinning projectiles were calculated using computational fluid dynamics method, and corresponding trajectory model was established to calculate drift. The reliability of ballistic model calculation was proved by comparison with experimental results. Combined with linearized swerving motion theory, some factors affecting drift were analyzed. The research results show that for low-speed spinning Projectile fired by recoilless rifles with Rifling, the influence of drift effect on impact point cannot be ignored. In addition, drift increases exponentially with dimensionless flight distance of Projectiles, and overturning moment coefficient and lift coefficient have significant effects on spin drift. The research outcomes will facilitate the effective completion of firing tables, thereby improving the shooting accuracy of recoilless rifle.
Rigid body modular modeling method for multiple reusable component weapon systems based on bond space theory
Authors: Gao Y F , Dai J S , Fu H , Liu Z L , Wu Y H
Published: December 2024

This article proposes a rigid body modular modeling method based on bond space theory. Aiming at the rigid components with the same characteristics that are heavily used in artillery weapon systems, the concept of bond space sub-model is proposed, and the rigid body module and constraint module are established and deduced. Considering the differences between ideal constraints and actual constraints such as gaps or heat losses, an elastic constraint bonding space module is proposed to improve the representation of ideal constraints. By combining bond space modules with the same characteristics and solving them, the process of analyzing complex systems will be greatly simplified. In addition, a study case of ammunition box feeding is presented to investigate the computational results of this modeling method; the analysis results show that this modeling method has good computational accuracy on the basis of improved computational efficiency.
ADPS: A Multi-sensor Assisted Driving Environmental Perception System for Edge Computing Devices
Authors: Li Haoyu , Li Hongbiao , Zhang Xiao , Zhang Yibin , Zhai Jiangwei , Lian Jing
Published: December 2024

In recent years, end-to-end neural networks have achieved a dominant position on various open-source autonomous driving datasets, especially in environment perception [1,2]. However, these networks are difficult to deploy due to high computational power requirements. Furthermore, many existing autonomous vehicles use edge computing devices with low computational power and the autonomous driving challenges for such vehicles are largely overlooked. In this paper, we propose an environmental perception system that includes vision-based panoramic perception and late-fusion-based 3D detection. It is suitable for vehicle-grade computing platforms with limited computational resources. Specifically, we first propose DFT-YOLOP, a dual-modal multitask network using visible light and infrared data trained on the BDD100K [3] and M3FD [4] datasets. The dataset tests demonstrate that, compared to numerous baseline networks, DFT-YOLOP offers a substantial improvement in road feature recognition, displays enhanced stability in adverse weather conditions, and delivers superior real-time performance during deployment. Secondly, we propose a late fusion algorithm that exploits the advantages of different sensors, including Vision-LiDAR Fusion Detection and Radar Data Enhancement. Finally, using the Assisted Driving Service Framework (ADSF) provided by the MDC 300F computing platform, we build the Assisted Driving Perception System (ADPS). Experiments in real road scenarios show that under the limited computational resources of MDC 300F, ADPS achieves high perception accuracy and real-time performance, meeting the perception requirements of autonomous driving under medium-speed driving conditions, which is of great significance for the improvement of the perception performance of autonomous driving vehicles using low-cost computational power platforms.
Research on the Influence of Cavities in Charge on the Formation and Penetration Performance of Jets
Authors: Zhang Xuepeng , Liu Yakun , Xu Can , Wang Yizhen , Yin Jianping
Published: December 2024

To investigate the effect of charge cavities on the formation and penetration of shaped charge warheads, we numerically simulate and calculate shaped charge warheads with different cavities using the finite element method. Combining theoretical analysis and numerical simulations, charge structure splitting was performed to obtain jet morphology and properties data for different cavity locations in both axial and radial dimensions. The mechanism of the effect of cavity position on detonation wave propagation, liner propellant, and jet formation processes in shaped charges is analyzed. It has been shown that charge cavities can change the propagation waveform of detonation waves. The effect of different cavity positions on the jet formation and penetration properties varies; Based on the detonation drive theory, a geometrical model was developed to investigate the effect of the charge cavity position on the jet velocity; The shaped charge warhead structure designed using this model can change the propagation path of the detonation wave, adjust the driving process of the shaped charge cover, and effectively increase the head velocity and penetration capacity of the jet. By studying the influence of the cavity on the driving and jet forming processes of the shaped charge cover, the results indicate that a model established by reasonably adjusting the charge cavity to improve the jet damage performance can provide a certain basis for further optimizing the design of the shaped charge structure.
Ignition characteristics of AlNi films with different modulation periods on TaN exchangers
Authors: Ren Xiao-Ming , Yao Hong-Zhi , Liu Hong-E , Xie Rui-Zhen , Yin Ming , Li Geng , Chu En-Yi
Published: December 2024

In order to reduce the ignition sensitivity of Al/Ni energy-bearing thin films, five kinds of Al/Ni energy-bearing thin films with different modulation periods were prepared by magnetron sputtering technology, and the transducer was prepared by integrating Al/Ni and TaN together by means of micro-electro-mechanical system technology. The surface topography and cross-section topography of Al/Ni energy-bearing thin films were characterized by scanning electron microscopy. The thermal reaction performance of Al/Ni energy-bearing thin films was detected and analyzed by differential scanning calorimetry. The ignition performance of Al/Ni@TaN was tested by capacitive ignition. The results showed that the Al/Ni energy-bearing thin films prepared by magnetron sputtering were tightly bonded. The temperature corresponding to the first exothermic peak of Al/Ni energy-bearing thin films showed increasing trend with the increase of modulation period. When the modulation period was 400nm, the minimum ignition voltage of Al/Ni@TaN transducer was 11V. When the modulation period was 800nm, the flame height of Al/Ni@TaN transducer was the highest under the condition of 25V and 33μf.
Dynamic Simulation Study of Artillery Firing Mechanism based on ADAMS
Authors: Yuan Zekun , Li Lizhou , Wan Chen , Zhao Jiajun
Published: December 2024

A multi rigid body dynamic model is established to address the dynamic issues of the firing mechanism of a certain type of artillery during the opening and closing of the latch, which can reflect the interaction between various components of the firing mechanism during the opening and closing of the latch. By adding the constraints and forces required for the dynamic simulation of the firing mechanism, as well as the contact/collision factors of each component during the firing action, a complete dynamic simulation of the firing mechanism was conducted in ADAMS software, and the interaction between each component during the opening and closing latch action of the firing mechanism was analyzed. This provides important experimental basis and support for the establishment of the firing mechanism model, and also provides reference for the spatial adjustment and optimization of the internal structure of the wedge bolt.
Researches on projectile muzzle velocity measurement system based on high-speed camera binocular intersection measurement and laser illumination
Authors: Liu Zhuohao , Luo Honge , Gu Jinliang
Published: December 2024

In order to reduce the impact of muzzle flame and smoke blurring on the flight trajectory imaging quality of projectile when measuring muzzle velocity in current weapon testing systems, a projectile velocity measurement system based on sequential pulsed laser illumination was studied. The wavelength of the pulsed laser is 532nm and the narrow-band filters with the same center wavelength were put in front of the camera lens which was used to suppress the influence of the flame. The pulsed laser and the filter helped the system to capture the images of the muzzle projectile wrapped in flames. The spatial movement distance of the projectile was calculated based on the principle of binocular intersection. The flying time of the projectile was determined by the high-speed camera shooting rate and the image frames intervals. The system was used to test the muzzle velocity of the projectile fired from a 12.7mm ballistic gun. The experiment results show that laser illumination effectively suppressed the influence of muzzle flames on projectile imaging. According to the calibration and binocular vision imaging algorithms, the muzzle velocity of the projectile was calculated with an accuracy of better than 0.3%. The method can measure the initial velocity of the projectile with the help of sequential pulsed laser illumination and short exposure time (as short as 1.1μs), which has great application value for range testing.
Peridynamic study on rock impact fragmentation process for deep space exploration
Authors: Qi Yuxuan , Jiang Chunlan , Jiang Zirui , Mao Liang
Published: December 2024

Impact experiment has been commonly used in deep space exploration and asteroid defence. In this paper, three types of rock fragmentation penetrators are employed, and the impact fragmentation process is simulated based on bond-based peridynamic (BB-PD) C++ computational code. The validity of computation is proved by the previous experimental and numerical research. Here, the influences of impact velocity and structure on the damaged mass of rock have been analyzed. The results show that the notched penetrator performs higher rock fragmentation efficiency. The structure of penetrator plays an important role on the damaged mass under the low impact velocity, and the penetrator mass becomes significant in the case of high impact velocity. Furthermore, the rock fragmentation mechanism has been revealed by analyzing the influenced regions and interaction effect. BB-PD simulation indicates the prospect of this notched penetrator for asteroid or planet rock fragmentation application.
Cooperative guidance law design for multiple-vehicle under distributed event-triggered mechanism
Authors: Gu Zhenzhen , Wang Xugang , Wang Zhongyuan
Published: December 2024

To address the operational requirements of engaging important surface vessels with multiple anti-ship missiles, this paper proposes an attack time cooperative guidance law based on distributed event-triggered mechanism. This law enables multiple missiles to simultaneously engage the target with minimal communication. First, design a two-stage guidance law that includes a cooperative guidance stage and an independent guidance stage. In the cooperative guidance stage, the time-to-go estimates of each missile are synchronized through inter-missile communication to achieve consistency. In the independent guidance stage, the missiles can independently guide themselves towards the target without the need for further communication. The key to the implementation of this strategy is the time-to-go estimates can represent the real time-to-go after achieving consensus. Furthermore, an event-triggered mechanism is introduced during the cooperative stage to effectively reduce the frequency of communication required during the cluster coordination process. Finally, the stability of the proposed cooperative guidance law is proven using Lyapunov theory, ensuring the absence of Zeno behavior. Numerical simulation results validate the effectiveness of the algorithm and confirm the correctness of the stability analysis.
Optimization of anti-airport runway munitions based on NSGA-III
Authors: Sun Xichen , Yao Wenjin , Chen Bin , Huang Jingnan , Li Chengyu , Gao Yifei , Shi Ji , Feng Jun
Published: December 2024

In modern warfare, as important infrastructure in marine engineering, the airport runways on the reef islands are the primary targets to be struck in wartime. This paper aims to shed light on the damage problem under the working condition of initial penetration followed by explosion. The numerical simulation was conducted through the establishment of the coupled correlation model between the crater radius, effective damage radius, explosion cavity radius and crater depth, as well as the multi-objective optimization model of the damage field parameters using Non-dominated Sorting Genetic algorithm optimization (NSGA-III) to explore the optimal velocity and charge depth when the damage field parameters are maximized. The results indicate that the destruction pattern of the airport runway changed from an open crater pattern to an bulging pattern and eventually to a hidden crater pattern as the charge location moved downward. Moreover, the destruction type of the airport runways by initial penetration with the projectile velocity of 300m/s~330m/s and explosion was the bulge mode, which contributed to the best destructive effect. Additionally, the optimal velocity of projectile penetration and the mass of charge was determined to be 320.807 m/s and 2.144 kg through NSGA-III.
The influence of initiation time error on the forming effect of multi-point initiation shaped charge jet
Authors: Zhang Bo , Yao Xiaoshuo , Bie Haiyuan , Wang Haifu
Published: December 2024

Aiming at the jet forming process of multi-point initiation shaped charge warhead with initiation time error, the jet offset of multi-point initiation shaped charge warhead with different liner thickness, liner cone angle and initiation radius under time error was studied by using ANSYS-LSDYNA software. The results show that increasing the wall thickness of the liner from 2mm to 5mm or increasing the cone angle from 50° to 80° will enhance the anti-interference ability of the jet, and the velocity angle and offset distance of the tip will decrease. When the radius of the initiation points increases from 30mm to 45mm, the velocity angle and offset distance of the jet head show a trend of decreasing first and then increasing. In addition, when the same change occurs in the structure of the liner, the method of reducing the degree of jet offset by changing the structure of the liner has a better effect on the time error with less concentration and has a poor effect on the time error with greater concentration.
Lattice-like Mechanical Metamaterials Structure Design Method Based on Convolutional Neural Network and NSGA-II Algorithm
Authors: Dang W , Miao C , Xu J , Mu X M , Niu H Y , Lu R J , Song Z W
Published: December 2024

Lattice-like mechanical metamaterials have excellent mechanical properties such as ultra-low density, high specific strength, and high energy absorption, and have broad application prospects in key components of platforms such as armored vehicles, helicopters, and aerospace vehicles. Aiming at the problem of inverse design of superstructure cellular structures, a study on the design method of cellular structures was carried out. Firstly, based on the uniqueness of cellular structural characteristics and the principle of comprehensive information, the cellular structural characteristic matrix and the cellular macroscopic mechanical characteristic matrix of coupled cellular configuration and structural parameters were proposed respectively; then, with the cellular structural characteristic matrix as input data and the macroscopic mechanical characteristic matrix of the cell as output data, a superstructure material performance prediction model based on convolutional neural network was established; further, with the minimum error between the specified target value and the predicted value of the macroscopic mechanical characteristic parameter as the criterion, a multi-objective optimization function was established; finally, the performance prediction model was combined with the fast non-dominated algorithm (NSGA-II algorithm) with elite retention strategy to construct a superstructure cellular structure design model, and the effectiveness of the structural design model was verified by case studies.
The influence of wave curvature on the trajectory characteristics of a high-speed projectile vertical water entry
Authors: Zhang Yufei , Dai Qi , Zhou Biaojun , Liu Xiaohan
Published: December 2024

To study the ballistic characteristics of high-speed vertical impact of projectiles on wave liquid surfaces, the method of Detached-Eddy Simulation (DES) with elliptic-blending Reynolds stress model is adopted to numerically simulate the high-speed vertical water entry of projectiles under different fifth-order Stokes wave curvatures. Through experiments, the accuracy and reliability of the numerical method were verified. Based on the numerical simulation method, it is stipulated that the convex curvature of waves is positive and the concave curvature is negative, and the influence of different wave curvatures on water entry trajectories is studied. The research results show that under small curvature wave conditions, the curvature of the entry position has a negligible effect on the axial load during the water entry process; negative curvature positions delay the peak time of the axial load in the entry wave valley compared to positive curvature positions. When the projectile vertically impacts waves at the position with zero curvature at the same actual water entry angle, compared to entering a quiescent free surface, the projectile experiences slower velocity decay, larger axial body loads, earlier peak time of axial load, shorter water entry process, and the trajectory of the projectile is still influenced by the curvature around this position.
Orthogonal simulation and experimental study on SLM process parameters for micro-sized high dynamic components
Authors: Lv Sining , Lou Wenzhong , Feng Hengzhen , Xiao Chuan , Li Shiyi
Published: December 2024

Metal Additive Manufacturing (MAM) technology has become an important means of rapid prototyping of special high dynamic complex components. This study employs selective laser melting (SLM) as a technological approach for investigating micro-sized high dynamic components. The parameters that affect SLM process are analysed, mainly including laser power, laser speed, laser diameter, and scan spacing. Based on prior studies, feasible parameter ranges are identified, and an orthogonal experimental design table is established for simulation and experimental co-verification. Range and variance analysis are conducted and the influence ability of each influencing factor is explored from both simulation and experimental aspects. The SLM process model is established using finite element software, taking into account parameters such as residual stress and maximum deformation. The conclusion is drawn that the order of influence of each factor on the preparation of micro-sized high dynamic components is: scan spacing>laser power>laser diameter> laser speed. Samples of components are fabricated and subjected to static testing. The density of the components can reach over 99.15%, and the structural strength can reach 348 MPa, which meet the required standards and confirm the simulation analysis. The results demonstrates that SLM provides a novel manufacturing method for micro-sized high dynamic components.
Failure rate analysis of loitering munition fuze safety system
Authors: Zhang Lingyun , Li Haojie , Zhang Chuanhao , Qiao Shixiang , Wang Pu , Yu Hang
Published: December 2024

The projection environment and operational characteristics of new types of munitions, such as loitering munitions and drones, differ significantly from those of conventional munitions. These new munitions are characterized by a weaker projection environment, longer cruise times, and secondary strike capabilities. Current fuze safety system design methods no longer meet these requirements. Therefore, it is necessary to propose new methods for calculating fuze failure rates to ensure the reliability of the fuze safety system. In this paper, aiming at the recoverable safety system of the loitering munition fuze, combined with the operational requirements and environmental characteristics of the loitering munition, and at the same time, based on the Markov chain, the failure rate analysis of the recoverable safety system of the loitering munition fuze was carried out. Also obtain the change of the failure rate of the fuze safety system under different states.
Study on carbonization treatment of polyaniline for improving electromagnetic wave absorption performance
Authors: Wang Yan , Hu Yubing , Jiang Wei
Published: December 2024

In this research, the electromagnetic wave absorption technology for military stealth, focusing on polyaniline as the primary subject. Compared to polyaniline, carbonized polyaniline achieves the improvement of electromagnetic wave absorption intensity and matching thickness of materials. The optimal reflection loss of carbon derived from polyaniline is -74.51 dB at 5.40 GHz with 3.36 mm.
Research on Pulse Linear Array LiDAR Point Cloud Enhancement Algorithm in Snowy Environment
Authors: Shi Xiaolong , Gao Mingze , Wu Yanjiang , Wang Weihan , Wang Fengjie , Han Shaorong , Chen Huimin
Published: December 2024

LiDAR point cloud data acquisition is difficult in snowfall environment, which leads to fewer point cloud datasets in snowy days and affects the subsequent research on target recognition algorithms in bad weather. In this paper, we investigate a point cloud enhancement algorithm based on pulse linear array LiDAR in snowfall environment. We use a linear array data acquisition method to collect the point cloud data of sunny and snowy days, and the point cloud data of sunny days and different degrees of snowy days are compared. We establish a linear array pulse LiDAR acquisition model and a single-line laser snowfall simulation model. The results show that a large number of snow particles gather in the vicinity of pulse linear array LiDAR and they are conical in distribution. The simulation model can generate point cloud data close to the real snow environment.
Research on effect of the pad material on stress of the explosive charge bottom during launching artillery ammunition
Authors: Xu F , Jiang J W , Xie H W
Published: December 2024

Using the generalized Maxwell visco-elastic constitutive model, the stress changes of the warhead explosive charge under high axial overload condition was simulated numerically by finite element method. The influence of Poisson’s ratio and elastic modulus parameters of the pad material on the Von Mises stress of the explosive charge bottom was analyzed. The results show that when the elastic modulus of the pad is small, its Poisson’s ratio is inversely proportional to the peak stress of the explosive charge bottom, while when the elastic modulus is large, its Poisson’s ratio has almost no effect; with the increase of the elastic modulus of the pad, the stress of the explosive charge bottom first decreases and then increases; compared to metal materials and flexible materials, engineering plastic gaskets have a better effect on reducing the peak stress of the explosive charge bottom.
Research on the Penetration Performance of Zirconium Liner
Authors: Ren X T , Zhang H Y , Yu Q B
Published: December 2024

As the core part of the shaped charge warhead, the selection of the material of the liner has an important influence on the formation and penetration ability of the shaped charge jet. In this paper, metal zirconium is used as the material of the liner. The Autodyn-2D numerical simulation platform is used to simulate the jet formation and penetration ability of the zirconium liner under the shaped charge structure. By comparing the penetration depth and opening diameter of the same target with the conventional liner material, the penetration ability of different material liners is analysed. The results show that the zirconium liner has good penetration performance compared with the titanium liner, and has good opening performance compared with the copper liner, and the zirconium liner jet will respectively produce secondary hole expansion phenomenon and secondary necking phenomenon when penetrating thick steel target and thick concrete target; When the zirconium liner penetrates the steel target with high strength. the opening ability will gain, but the penetration ability will be impaired. Moreover, the tiny change of the target thickness has little effect on the residual velocity and the opening diameter of the zirconium liner head; The velocity loss of the jet head of the zirconium liner is closely related to the strength of the target plate and the thickness of the target plate. This relationship makes the zirconium liner more conducive to the penetration of medium strength and medium thickness targets.
Effect of hollow degree on the mechanical properties of simple cubic structures mechanics metamaterials
Authors: Yang Z Z , Xu J , Mu X M , Niu H Y , Wang Q C , Bai L H
Published: December 2024

The research object of this article is simple cubic mechanical metamaterials. By changing the hollow degree of the composed of cell elements, the influence of hollow degree on the mechanical properties of simple cubic mechanics metamaterials during compression is analyzed. Results reveal that properly increasing the hollow degree of components can improve the compressive strength of simple cubic mechanics metamaterials and stabilize the macroscopic energy absorption characteristics during the compression process. But as the hollow degree increases, the failure of the cell elements changes from compressive failure of the rod to shear failure at the junction, and the compressive strength of the mechanical metamaterial decreases.
Non-Singular Fast Terminal Unidirectional Sliding Mode Control for Fixed Rudder Two-Dimensional Trajectory Correction of Projectile
Authors: Feng Dewei , Wang Liangming , Yang Zhiwei , Huaiwei A , Chen Zhi
Published: December 2024

This study addresses the control issue of a fixed-rudder two-dimensional trajectory correction projectile. Initially, a novel roll angle controller was designed based on the unidirectional sliding mode theory and the fast terminal sliding mode theory. Subsequently, the system’s response time and robustness were enhanced through the design of a unidirectional sliding mode auxiliary surface and non-singular fast terminal attractor parameters. Finally, the stability of the designed roll angle controller, which meets the system’s stability requirements, was proven using the Lyapunov stability theorem. Simulation verification of the designed controller was conducted using simulation software, and the simulation results indicate that the controller possesses good robustness.
Simulation analysis of the influence of flow field structure changes in-bore on the barrel life
Authors: Zhao Na , Zhang Long , Li Rui , Ke Biao , Han Rufeng
Published: December 2024

By regulating the flow pattern of gunpowder gas and increasing the vortex dissipation intensity near the wall of the barrel, the thermal effect of gas on the wall of the barrel can be reduced, which can effectively reduce the thermal erosion of the barrel and improve its service life. Based on the initial boundary conditions determined by one dimensional two-phase flow interior ballistic model, numerical simulations were conducted using CFD method to investigate the influence of different structural shapes on the thermal flow field inside the barrel, and the corresponding barrel erosion situations were analysed for different structures. The result shows that adding a micro disturbance flow structure to the inner bore of the barrel can reduce the heat flux density at key points, thereby reducing the single shot barrel erosion and improving the barrel life. This result can provide some references for the design of artillery that needs to extend the barrel life.
Shock wave overpressure distribution behaviour in free-field by reactive filling piercing projectile penetrating multi-layered plates
Authors: Xiang J A , Yan Y G , Liu A X , Wang H F
Published: December 2024

The experiment of reactive filling piercing projectile (RFPP) penetrating the multi-layered structural plates is conducted to investigate the impact-induced initiation model and behind-plate deflagration shock wave overpressure mechanism is developed according to the explosion similarity principle and the one-dimensional stress wave propagation theory. The concept of effective deflagration point is proposed to reveal the propagating mechanism of deflagration shock wave. The results demonstrate that at the impact velocity of 688 m/s, the position of initiated reactive filling deflagrated behind the plates range from 0375 to 0.05192m. A significant multi-peak characteristic is presented in the relationship between behind-plate overpressure and time, as a result of the sequential impact behaviour of RFPP impacting the multi-layered plates, with the later overpressure peak exceeding the initial one.
Experimental and Numerical Study on Ballistic Characteristics of Vertical Water Entry for High-speed Truncated Head-type Projectiles
Authors: Zhou Biaojun , Zhao Zijie , Zhang Hui
Published: December 2024

To achieve the ballistic control method of rapid levelling the projectile after the water entry, an asymmetric head-type design is proposed. To analyze the trajectory of center of gravity of the projectile with an oblique truncated head, comparative experiments of the vertical water entry of the projectile at different velocities was conducted using a high-speed camera to obtain the trajectory and the variation of the deflection. The effects of different cutting angles and water-entry velocities on the trajectory characteristics of the projectile and the cavity flow field were investigated by numerical simulations. The results indicated that the increasing cutting angle of the projectile will increase the curvature and deflection angle of the trajectory after the projectile enters water, and the yawing angle of the projectile will increase by 5 degrees for every 5 degrees increase of the cutting angle in the study area within 9 milliseconds. The asymmetric head-type of the projectile will affect the shape of the cavity, and the cavity will appear an asymmetry and form cavities at the head and tail, respectively, and the flow field pressure will change drastically.
Effect of quenching and tempering process on microstructure and properties of 14Cr17Ni2 stainless steel
Authors: Chen Shan , Zhao Ning , Yang Chunguang , Zhang Lei , Yang Fang , Shen Xinjun
Published: December 2024

14Cr17Ni2 is a martensitic stainless steel with good matching of strength and toughness. Its mechanical properties depend on quenching and tempering process, especially tensile strength and impact toughness require appropriate heat treatment process to achieve the mechanical properties required by design. In order to solve the problem that the impact energy is difficult to reach the standard, this paper studies the relationship between the temperature time of quenching and tempering and the microstructure and properties, and obtains that the hardness of HBW328 can meet the requirements when the quenching temperature is 950 °C and the tempering temperature is 600 °C, so as to realize high-efficiency and high-quality processing of turning and tooth making.
Investigation of the Al alloy armor materials: A review
Authors: Zhou Tian , Wang Yangwei , Bao Jiawei , Zhao Pingluo , An Rui , Zhang Changle , Zhang Hao
Published: December 2024

Al alloys have garnered profound scholarly interest for their utilization in armored vehicles and an array of military components, owing to their noteworthy properties which encompass high specific strength, exceptional fracture toughness, unparalleled corrosion resistance, and remarkable ballistic characteristics. Additionally, their exceptional formability coupled with economic feasibility enhances the prospects for large-scale production and deployment, thereby positioning them as a highly preferred material option. The ballistic impact mechanism in Al alloys is an intricate mechanical process, intricately intertwined with the target material’s strength, hardness, ductility, density, toughness, and thickness, as well as the projectile’s characteristics. Currently, a range of lightweight Al alloy armor materials have been engineered to possess superior strength and ductility, rendering them ideally suited for a diverse array of ballistic impact applications. This study aims to consolidate current research findings on Al alloy armor materials, with a keen focus on three pivotal dimensions: ballistic resilience, stress corrosion cracking resistance, and weldability. By integrating insights from diverse research endeavors, we endeavor to deepen our comprehension of these key properties, ultimately laying a solid theoretical and experimental groundwork for the progression of Al alloy armor materials.
Simulation study on the jet formation of high-entropy alloy shaped charge liner
Authors: Zhang Hongyu , Wang Jin , Qiu Wenhao , Ma Chen
Published: December 2024

The high-entropy alloy liner has the characteristics of wide composition and performance control range, high density, high sound speed, and certain chemical activity, which makes it unique in the application of shaped charge warhead. Based on CoCrFeNiAl high-entropy alloy, the static and dynamic mechanical properties of high-entropy alloy were carried out by universal material testing machine and split Hopkinson pressure bar (SHPB). The static and dynamic stress-strain curves of high-entropy alloy were obtained, and the Johnson-Cook constitutive model parameters of high-entropy alloy were fitted. Based on the AUTODYN-2D numerical simulation platform, the jet formation behavior of CoCrFeNiAl high-entropy alloy liner was studied. The distribution characteristics of velocity field and density field in the jet formation process of high-entropy alloy liner were analyzed, and the influence of cone angle of high-entropy alloy liner on jet formation evolution, fracture, velocity field and density field was revealed. The results show that the jet head accumulation is caused by the existence of “reverse velocity gradient” in the high-entropy jet formation process. With the increase of the cone angle of the liner, the velocity of the jet head of the CoCrFeNiAl high-entropy alloy decreases, but the overall formation performance of the jet is better. Under the condition of different cone angles, the density change curve at the top axis of the high-entropy alloy liner shows the “three peaks” phenomenon. The work can provide a reference for the structural design of new high-entropy alloy liner.
Analysis of Explosion characteristics of L-Type Explosive Train in Fuze based on LS-DYNA
Authors: Zhong Yunling , Zhao Yiju , Wang Bin , Gong Yu , Guo Meng
Published: December 2024

In order to study the explosion characteristics of explosive train in fuze, and provide reference for the design of explosive train, the simulation calculation of explosion characteristics of L-type explosive train is carried out, and a simplified model is established for theoretical analysis. The analysis results show that the initiation point of the L-type explosive train should be designed in the middle and back end of the detonating charge column, so that the detonation pressure at the detonation tube can be larger; The air gap should be reduced as much as possible when designing the explosive train; Proper thickness of metal structures in the explosive train can influent the detonation waveform become more complex shock wave chasing and superposition, which will increase the detonation pressure.
Shock Response Characteristics and Unreacted Equation of State Calibration of GAP/RDX/TEGDN propellant
Authors: Xin Wang , Yanqing Wu , Liansheng Zhang , Jun You
Published: December 2024

Understanding the shock response characteristics of propellants is crucial for studying the safety of the shock wave dominating shock initiation. To study shock response characteristics of high-energy solid propellant (GAP/RDX/TEGDN propellant, GRT propellant) and obtain its unreacted equation of state (EOS) parameters, a shock response experiment (plate impact experiment) was conducted using a caliber 57 mm single stage light-gas gun device. The propellant/window interface particle velocity is measured by using a velocity interferometer system for any reflector (VISAR), and the corresponding mechanical parameters of GRT propellant are obtained by the impedance matching method. The Hugoniot parameters of GRT propellant further were obtained by the parameter inversion method based on Abaqus/explicit, calibrated the unreacted EOS. The experiment results show that: At an impact velocity of 212 m·s−1 and 282 m·s−1, the propellant/window interface particle velocity time-history curve shows a double wave composed of elasticity and viscoplasticity. The shock front rise time in the viscoplasticity wave stage is relatively slow and shows shock viscosity characteristics. The shock viscosity is attributed to the viscous dissipation of each constituent and the wave scattering caused by a wave impedance mismatch between each constituent. Its duration decreases with impact velocity increasing. In addition, the unreacted EOS fitting curve is consistent with the experimental result inversion value and the calibrated parameters are valid.
Preparation and ballistic performance of super porous photocurable gun propellant
Authors: Li Manman , Guo Zhigang , Gao Yuchen , Wang Qionglin , Yang Weitao
Published: December 2024

Porous propellants were fabricated using an extrusion 3D printer. A novel formulation was developed, containing terminated acrylate-based poly (3-nitrilomethyl-3-methyloxetane) (APNIMMO) as the prepolymer and hexanitrohexaazaisowoodzane (CL-20) as the high-energy solid filler. Photocurable gun propellant slurries were prepared utilizing the acoustic resonance mixier, and subsequently, gun propellants with a core-shell structure were fabricated via extrusion 3D printing technology. The combustion performance and interior ballistic performance of these propellants were tested and analyzed by closed bomb and 12.7mm test gun. The results demonstrated that the propellant grain with shell-core structure possesses better combustion progressivity. Meanwhile, the incorporation of lattice structures in photocurable gun propellants led to increased chamber pressure and muzzle velocity. Conversely, the addition of shell-core structured propellant grains resulted in comparable muzzle velocity but decreased chamber pressure. These findings underscore the significant role of rational structural design in optimizing ballistic performance.
Experimental study on the DC response of parallel NTC thermistors to sensitive semiconductor bridge transducers
Authors: Jin Hao-jie , Niu Hui-yuan , Ren Wei , Ji Xiang-fei , Wang Li , Li Hui , An Cheng-yuan
Published: December 2024

The application of parallel thermistor is an essential method for improving the critical fusing current of semiconductor bridge (SCB). In this paper, constant current power supply and infrared test system are employed to experimentally investigate the effect of parallel negative temperature coefficient (NTC)thermistor on the response of semiconductor bridge under various DC excitations. The test results demonstrate a comparison between the SCB (NTC-SCB) with negative temperature coefficient thermistor in parallel and the SCB without NTC. The temperature in the bridge region can be reduced by 68% with a more than one-fold increase in the critical fusing current. And the shunt effect of NTC thermistor is 34.4%-74.4%.