bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on Safety Technology of Anti-Sympathatic Detonation for Grenade Assembly
Authors: Yunpeng Jia , Hao Yang , Peng Tian , Jinsong Liu , Cuiling Guo , Limin Sun , Jun Gao , Fei He , Rui Hong , Ming Yang , Wenjun Zhang
Published: June 2023

Base on the sympathatic detonation experiment between grenades and accessories, the actual data was obtained. The assembly link with the greatest risk of explosion was summarized by the data analysis results. Base on the obtained experimental data, the process and design requirements of the relevant assembly functional units ware proposed. On the other, the production data collected in the actual production process was comprehensively analyzed and feedback. That is possibility which fundamentally solves the risk control problem of the grenade assembly process.
Theoretical basis and performance research on advanced non-contacting ion beam manufacturing process for optical materials
Authors: Li Xiaojing , DasenWang  , Yang Wenzhi , Xu Min , Zhao Shiyan , Nie Fengming , Zhang Xu
Published: June 2023

Ultra-smooth surface is very important for the performance of high energy optical system in the defence field. Low quality optical elements will cause energy loss and affect the performance of the optical system. Ultra-precision manufacturing technology of optical components is the key technology to obtain high quality optical components. As an advanced ultra-precision and no-contact surface processing technology, Ion Beam Manufacturing (IBM) was studied. Based on the analysis of the relationship between the ion beam current density distribution parameters obtained by faraday scan and the removal function, more effective removal function calculation method was found, the removal function model for IBF fused silica was established. The Molecular Dynamics(MD)simulation to study interaction between incident ion and optical substrate. Ion particle motion behaviour were obtained under different incident energies. The effect of incidence angle on surface roughness were carried out, lower surface roughness by smaller angle incident, ultra-precision surface of optical components were obtained by IBF experiments.
Optimization design of a novel zero Poisson’s ratio honeycomb structure for in-plane mechanical performance
Authors: Liao Xuezhi , Wang Hongbo , Li Baoyu , Zhao Xiaoning
Published: June 2023

The excellent deformation performance of structure is the material basis of intelligent morphing aircraft. In this study, a zero Poisson’s ratio honeycomb structure consisting of sinusoidal corrugated walls is applied to morphing aircraft. The in-plane mechanical properties of the structure are deduced theoretically based on the assumption of small strain. According to the application requirements of tensile deformation and shear deformation, an optimization model is established with geometric parameters as optimization variables, and its mechanical properties are optimized by interior point method. The results show that the equivalent mechanical properties of the new zero-Poisson ratio honeycomb structure are greatly improved. The research provides important reference for the innovative design and optimization of honeycomb structures.
Parameter identification of contact model for tank saddle ring system based on genetic algorithm and BP neural network
Authors: Ma Yuze , Liu Feifei , Si Zhihui , Gerile Qimuge , Yang Kai , Li Haoyang , Cheng Yiguang
Published: June 2023

This paper is devoted to present an experimental identification method of tank saddle ring system parameters based on BP neural network algorithm and genetic algorithm. The contact parameters in mechanical system cannot be obtained directly through measurement, and it is inevitable that there will be errors between the parameters estimated by engineering experience and the real value. In this paper, a 6-degree-of-freedom swing experimental device of tank turret is built, the excitation source is 1Hz sine function, the contact stiffness and contact damping coefficient are identified by constructing error functions based on simulation results and data of four laser displacement sensors distributed around the saddle ring, by the combination of BP neural network and genetic algorithm. Then, the sensor data in the test results and simulation results are compared to further verify the accuracy of the turret model and parameter identification method.
A Novel High Efficiency Synthetic Fire Strike System
Authors: Yuan Yuwen , Wang Huifang , Niu Tianhong , Jia Qiang , He Weizhen , Peng Pei
Published: June 2023

A new type of multi-artillery, multi-functional, multi-purpose synthetically-arranged battle group with high-efficiency fire strike system is constructed. The hierarchical structure and weight relationship of the system are determined by the AHP analytic hierarchy process, and then the inherent ability of each performance index is calculated by the fuzzy membership degree theory. These methods are used to establish the combat effectiveness evaluation model of high-efficiency fire strike system. The analysis shows that, for different damage targets, the deployment method of the efficient fire strike battalion has significantly improved the combat effectiveness of the traditional howitzer battalion. The research results have certain reference value for other arms to improve their weapon combat capabilities, conduct joint weapon operations and evaluate system combat effectiveness.
Adaptive scheduling algorithm for phased array fire control radar based on comprehensive priority
Authors: Wang Yansong , Han Xing , Chen Chun
Published: June 2023

Aiming at the problem of resource allocation in multi-task scheduling of phased array fire control radar, this paper proposes an adaptive scheduling algorithm based on comprehensive priority, that is, the shooting advantage degree of phased array fire control radar to different targets is calculated by using Analytic Hierarchy Process, and then combined with the priority of the work mode and the task deadline to carry out the comprehensive priority planning of the task. In the performance evaluation algorithm, the index of shooting value rate is proposed to evaluate the performance of the scheduling algorithm for high shooting advantage degree tasks. The simulation results show that, compared with the traditional scheduling algorithm, the proposed scheduling algorithm significantly improves the shooting value rate and the comprehensive scheduling ability of phased array fire control radar.
Investigation of Gas Exchange Process on a Highly-Intensified Single Cylinder Diesel Engine with Late Intake Valve Closing Miller Cycle
Authors: Wang Ziyu , Cheng Xiuwei , Liu Jinlong , Li Xiaojuan , Cao Rulou , Li Chaofan , Che Kaikai , Li Yufeng
Published: June 2023

Late intake valve closing (LIVC) Miller cycle was used on a highly-intensified single cylinder diesel engine to reduce the maximum combustion pressure and temperature. Three intake cams with three LIVC timings were designed and tested on the engine bench. The gas exchange process of the Miller cycle was investigated by a 1-D simulation model which was calibrated by experimental data. The analysis was conducted at a constant speed of 3600 r/min and two IMEP loads of 25 bar and 15 bar respectively. Miller depth is named to reflect the retard degree of the LIVC timing. The analysis results show that as the LIVC Miller depth increases, the intake pressure is considerably increased in order to keep the same load. This causes an increase in intake boost work. In addition, the averaged intake pressure difference during the period of BDC-IVC is negative and increases with the retard of IVC timing, resulting in more backflow with the LIVC timing. The backflow rate quickly increases from nearly zero at the original IVC timing of 70°CA ABDC to 22% at the deepest LIVC timing of 120°CA ABDC. Furthermore, the charging efficiency and pumping loss reduce with the retard of IVC timing. The Miller loss is obviously increased at deeper LIVC Miller cycle. On the other hand, the exhaust energy slightly decreases with the retard of IVC timing in this study case, but the ratio of the boost work over the exhaust energy increase considerably with the retard of IVC timing.
Influence of slenderness ratio on the lateral force of a slender body at high angle of attack
Authors: Wei K , Chen S S
Published: June 2023

The slenderness ratio is an important feature of the slender body, but the effect of slenderness ratio on the lateral force of the slender body at high Angle of attack have not clearly. In this paper, the Detached eddy simulation (DES) method is verified and adopted to simulate the flow of five models with slenderness ratio SR=10, 12.5, 15, 17.5 and 20. The simulation is carried out under the conditions of 15.3m/s incoming flow and 55° Angle of attack. Based on the simulation results, the vorticity magnitude and surface pressure coefficient of the five models are compared. It is concluded that the increase of slenderness ratio will increase the fluctuation cycle of pressure along the axial direction. To further analysed the relationship between pressure distribution and lateral force in different models, the pressure values of multiple sections were extracted and integrated to draw the change curve of unit lateral force coefficient along the X direction. From the analysis of unit lateral force coefficient, the difference of pressure between the two sides induced by asymmetric vortex at the head is the main source of lateral force. The unit lateral force coefficient (Cfzpm
) of the model with small slenderness ratio oscillated more dramatically and attenuated more slowly than that of the model with large slenderness ratio, due to the interaction between the head vortex and the high-pressure region at the bottom of body with a small slenderness ratio at a large Angle of attack. The interaction between the head vortex and the bottom high-pressure region makes the lateral force coefficient of the model with small slenderness ratio not necessarily significantly smaller than that of the model with large slenderness ratio. With the increase of slenderness ratio, the influence of head vortex on the pressure distribution of rear surface decreases, and the asymmetry of rear surface pressure distribution decreases. The conclusion of this paper can help to solve the problem of lateral force coefficient variation that may occur in multistage rocket engineering.
Propagation characteristics of rotating detonation with high-temperature hydrogen gas
Authors: Bai Q D , Han J X , Zhang S J
Published: June 2023

The rotating detonation characteristics of high-temperature hydrogen-rich gas were studied. Hydrogen-rich gas was generated by the pre-combustion of hydrogen, and a rotating detonation experiment of hydrogen-rich gas and air was subsequently performed. The auto-initiation of high-temperature hydrogen-rich gas was observed in the experiment, and the influence of pre-detonation tube ignition on the steady propagation of the detonation wave was analyzed. The results show that high-temperature hydrogen-rich gas and air have the ability to spontaneously form rotating detonation waves. The operation of the pre-detonation tube has a significant influence on the propagation mode and propagation velocity of the continuous rotating detonation wave after auto-initiation. The rotational detonation wave formed by the auto-initiation of hydrogen-rich gas and air has a short instability in the propagation process. The propagation velocity of the detonation wave before and after the unstable state is 1345.4 m/s and 1425.3 m/s, respectively, the unstable state is 1345.4 m/s and 1425.3 m/s, respectively.
Research on Synchronous Accuracy of Sight and Gun in Remote Control Weapon Station
Authors: Jie Li , Haibo Wang , Xiaobin Pang , Xingwang Liang
Published: June 2023

The synchronous accuracy of sight and gun is an important factor affecting shooting accuracy and first hit probability of remote control weapon station. In view of the problem that the angle between the line of sight (LOS) and the line of gun (LOG) in high and low direction is not consistent, this paper analyzes the cause of the angle between the LOS and the LOG in high and low direction in a batch of remote control weapon station production, and according to each kind of influence factor has given the corresponding solution measure. It is proved that the synchronous accuracy of sight and gun in remote control weapon station can be improved effectively through precision control of each link.
Research on automatic metering and pneumatic vibration conveying technology of energetic powder materials
Authors: He Fei , Yang Hao , Sun Yang , Liu Jinsong , Gu Peng , Jia Yunpeng , Mu Jiaqing , Li Jing , Ou Xibin , Zhu He
Published: June 2023

In view of the need to improve the automation and weighing accuracy of solid energetic materials in the weighing process, to reduce the process safety risk of the automatic conveying and loading process and improve the equipment safety control ability, a weight-loss pneumatic vibration conveying device is designed, which adopts the method of weight loss measurement. Through the weighing sensor installed on the weighing platform, the weight of the materials in the weighing hopper is fed back to the controller in real time, The controller obtains the weight reduction per unit time (i.e. the actual flow) through the internal algorithm. According to the difference between the actual flow and the set flow, the controller outputs the speed signal to control the motor speed to achieve the purpose of accurate feeding. A linear pneumatic vibrating conveying chute is designed to continuously convey materials at a certain speed. The linear pneumatic vibrating chute has good linear control through the adjustment of leaf spring, amplitude and frequency, and can realize the automatic and safe measurement and transportation of solid energetic materials.
Sensitivity Study on Typical Parameters of Underwater Explosion Numerical Simulation
Authors: Chen D , Zhang L J , Lv Y Z , Li B H , Gu H P
Published: June 2023

In the numerical simulation research for underwater explosion, the selection of simulation parameters has a great influence on the results of numerical calculation. Based on the one-dimensional spherical symmetry model, this paper systematically studies the influence of three factors: grid size, water state equation and artificial viscosity coefficient on the important physical parameters of water explosion when TNT explosive is exploded in water. The important physical parameters selected for the explosion in water are the shock wave intensity, the maximu m radius of the bubble and the pulsation period of the bubble. A series of studies are carried out on underwater explosions with different grid sizes, so as to obtain the corresponding recommended grids that meet the calculation accuracy. The influence of different water state equations on the simulation results is discussed. The effect of artificial viscosity coefficient on the simulation results is analyzed. Finally, the similarity law of the model is studied to verify the universality of the model parameters.
A modified formula to predict the penetration depth for jet penetrating spaced target plates
Authors: Lei J Y , Dou J H , Jing Y D
Published: June 2023

In order to predict the penetration depth for jet penetrating spaced target plates, a modified formula with exponential form is proposed in this work based on the existing method. The processes of jet penetrating homogeneous target plate and spaced target plates are observed by simulation, and the penetration depth of different layers is obtained. The relationship between the number of layers and the penetration depth is described by the proposed formula, in which the parameters are determined by the simulation results. The penetration depth for jet penetrating spaced target plates can be predicted by the proposed formula. By comparison, the predictions well agree with the actual data, which indicates the modified formula can be a reference to predict the penetration depth for spaced target plates.
Study on Thermal Decomposition and Thermal Safety of Mixtures of Highly Active Aluminum Powder and Nitramine Explosive
Authors: Pei Qing , Li Meng , Li Heng
Published: June 2023

The newly prepared and stored highly active aluminum powder were mixed with common nitramine explosives HMX and CL-20 at a mass ratio of 1:1, respectively. The effects of the two kinds of high active aluminum powder on the thermal decomposition properties of HMX and CL-20 were investigated by differential scanning calorimetry (DSC). The thermal explosion critical temperature of the mixture of high active aluminum powder and nitramine explosive was calculated. The result shows that after joining highly active aluminium powder, highly active aluminium/nitramine explosive mixture, moderate and apparent activation energy decrease thermal decomposition peak suggests that highly active aluminium can contribute to the thermal decomposition of HMX and CL-20, compared with highly active aluminium stored after a certain period of time, the new system is highly active aluminum powder with a mixture of nitramine explosives with lower apparent activation energy, At the same time, the critical temperature of thermal explosion also decreased significantly, which indicated that the newly prepared high-activity aluminum powder had higher chemical reactivity, but its thermal safety was reduced.
Numerical simulation study on the slow cook-off response characteristics of PBX explosive
Authors: hai Deng , xin-lian Ren , sha Gou
Published: June 2023

The zero order reaction kinetic model was used to simulate the heating of energetic binder PBX charge at four heating rates of 3.3K/h, 6K/h, 9K/h and 30K/h, respectively. The key parameters such as the evolution of temperature field, ignition time, ignition temperature and ignition area were obtained. The results show that during the slow Cook-off process of energetic binder PBX explosive charge, before the thermal decomposition and acceleration reaction, it is a heat conduction process, with large internal temperature gradient, low charge center temperature and high charge edge temperature; When the temperature rises to 396K, the thermal decomposition rate of the explosive increases, and heat accumulation occurs in the charge; The ignition position of charges with different heating rates changes. With the increase of heating rates, the ignition position changes from a point in the center to two points on the axis that gradually move away from the center to both ends, and then to four points that gradually move away from the axis to four end angles. Finally, the ignition reaction occurs.
Intracranial pressure measurement under shock wave based on physical head surrogate
Authors: Xiong Man-Man , Tian Cong-ling , An Shuo , Zang Li-wang , Xu Cheng , Li Feng-xia
Published: June 2023

In order to explore the intracranial pressure response under different sensor fixation modes, the experimental study on the pressure measurement based on physical head surrogate under shock wave is carried out. The influence of different sensor fixation methods on the intracranial pressure was analyzed. The results show that sensor fixation mode has little influence on the pressure test results. The deviation between the pressure peak and impulse is only 3.62% and 4.54% in the two modes of hot melt supporting and free suspension. The deviation of pressure peak value between metal supporting and free suspension is 5.59%. In comparison, hot melt supporting fixation has less influence on intracranial pressure results. The orientation of sensor sensitive surface has little influence on the pressure test results. When sensor was fixed by the metal bracket, the deviation of pressure peak is only 4.03% between sensitive surface face to impact source and sensitive surface back to shock source.
Quasi-static and dynamic mechanical characterization of clay and ballistic soap
Authors: Wang L Q , Wen Y K , Dong F D , Qin B , Qu Y , Sun F
Published: June 2023

Ballistic gelatin, soap, and clay are three human simulated target materials commonly used in the field of wound ballistics research. Currently, there are more studies on ballistic gelatin’s mechanical properties, but rarely on clay and soap. In this paper, the mechanical properties of clay and soap materials were tested by using universal material testing machine and Hopkinson bar, respectively, and their stress-strain curves were obtained under different temperatures (4°C, 15°C, and 25°C) from quasi-static to dynamic loading. The test results showed that the clay material was sensitive to temperature and strain rate in quasi-static conditions, its stress-strain curves showed nonlinear strengthening characteristics, and the stress always increased without strength decrease during the loading process; the dynamic compression mechanical properties of clay were significantly higher than the quasi-static mechanical properties, showing obvious strain rate strengthening effect. In quasi-static compression experiments, the stress-strain curves of soap material showed bilinear elastic-plastic material characteristics; when the strain was less than 0.1, it was insensitive to temperature and strain rate, and only when the strain was more significant than 0.1 did it show a certain temperature and strain rate correlation. The dynamic compressive mechanical properties of soap are significantly higher than the quasi-static mechanical properties, showing a significant strain-rate strengthening effect. The stress of soap at the same strain rate is slightly less than that of clay. These results not only help provide more accurate material parameters for relevant numerical calculations but also help to provide references for the development of new bionic materials.
Effect of ventilation mode and rate on airborne transmission of respiratory disease in indoor environments
Authors: Wu Jialin , Geng Jing , Weng Wenguo , Fu Ming
Published: June 2023

Ventilation might play an important role in airborne transmission. By using the computational fluid dynamics (CFD) method, ventilation modes, ventilation rates, and infection source’s face direction were considered in a multi-person indoor environment (10 m*10 m*3 m). The airflow patterns, virus concentration distribution, and infection probability were studied. The results showed that the virus concentration was lower with displacement ventilation (DV, lower in, upper out) than mixing ventilation (MV, top-centre in, upper out) or natural ventilation (NV, upper in, upper out). In 2 air changes per hour (ACH), the infection risk of susceptible persons in MV and NV might be about 2.43-fold and 1.30-fold more than that in DV. Increased ventilation usually reduces viral concentrations and the risk of infection. For the height of breathing zones, the average virus concentration at 12ACH was 49.78%-78.72% lower than that at 2ACH. For susceptible persons at a distance of about 2.8-4.2 m to a COVID-19 infector with 30 min exposure time, the long-range airborne infection probability might be 11.53% (±5.86) (2ACH), 4.96% (±1.82%) (6ACH), and 2.96% (±1.91%) (12ACH).
Effect of solution and aging treatment on microstructure and hardness of aluminum bronze
Authors: Chen Shan , Zhang Peng , Jia Dongsheng , He Yaoyu , Zhang Liqin , Zhou Jiawei , Xue Dong , Yue Feng
Published: June 2023

Due to their excellent corrosion resistance and wear resistance, bearing bushes made of aluminium bronze are widely used in pumps, heavy equipment and marine equipment. Aluminium bronze is also used in valve for tank to improve defence. This work aims to enhance the hardness of QAl10-3-1.5 extruded aluminium bronze by performing heat treatment at different solution temperature, quenchant, and aging temperature. The results show that when the aluminum content of the raw material is more than 9.4%, aluminum bronze after solution and aging treatment obtain a significant enhancement of hardness. The value of hardness can reach above 207HB, which meets the design requirements of drawings and improves the wear and corrosion resistance.
Simulation Study of Structural Factors Affecting the Performance of Thermal Jacket for Gun Tubes
Authors: Duan Dongyu , Zhang Jie , Li Ying , Sun Quanzhao
Published: June 2023

Most of common thermal jackets for gun tubes are composite types, which have large mass and complex structures. With the development of material technology, a single-layer thermal jacket using new composite materials with low thermal conductivity has good protection effects on gun tubes. The design of a single-layer thermal jacket requires consideration of thickness, air gap, material properties and structural strength. In order to study the structural factors that affect the performance of the single-layer heat jacket, the models of various structural dimensions through a 3D modeling software were established, a thermal-mechanical coupling system was built using a finite element simulation software to simulate the different thermal jacket models. The results were compared and analyzed, and the structural factors that affect the performance of the thermal jacket were investigated.
Experiment and instantaneous driving simulation of explosion dispersion process of central tube for submunition
Authors: Peng Hong Zheng , Yuan Jun Ming , Huang Si Fan , Huang Kai Shu , Zhao Wei , Liu Jia Yao , Qin Yue , Zhou Han Peng
Published: June 2023

In order to study the influence of explosion dispersion of submunition on the dispersion velocity and pressure characteristics of subunits, the experimental study of explosive dispersion of the central tube was carried out when the explosives with low detonation velocity were applied in central tube as the main charge. In addition, the explosion dispersion test process was recorded by high-speed photography. RDX-based aluminized explosive samples with low detonation velocity were prepared and tested, and the low detonation velocity performance changes under different charge diameters and densities were obtained. Based on the explosive dispersion test of the central tube of the submunition, the physical model and three-dimensional axisymmetric finite element model of the central tube, subunit and aluminium alloy shell with prefabricated grooves are established. The fluid-structure coupling calculation method is used to simulate the explosive dispersion process. The simulation results are compared with the test results, and the pressure distribution characteristics of the subunit and the variation law of the dispersion velocity are analyzed. The effectiveness of the engineering calculation method of JWL equation model parameters is verified. The results show that using RDX based aluminized low detonation velocity explosive as the main charge of the central tube structure can achieve the design goal of the explosive dispersion for submunition, and the explosion dispersion model of submunition can accurately describe the dispersion characteristics of the subunit. The research results can be used to guide the structural design of submunition warhead.
Optimization of Al/PTFE applied to detonation network used for micro shaped charge warhead.
Authors: Wen X M , Wang S , Kang H , Wang J H
Published: June 2023

In order to improve the detonation performance of the explosive network on the basis of achieving high safety and reliable detonation, 3,4-dinitrofurazanyl oxyfurazan (DNTF) was used as the main explosive, glycidyl azide polymer(GAP) was used as the binder, and other auxiliary agents were added to the basic charge formula. Then, polytetrafluoroethylene (PTFE) and aluminum (Al) were introduced to further enhance the output power of the charge formula. The influence of two introduction methods of PTFE and Al was evaluated: directly mechanically mixing method and activation method by metal ball milling. A variety of tests such as particle size, morphology, detonation performance in groove were carried out to study the difference between mixed Al/PTFE and milling activated Al/PTFE. The experiment showed that particle size becomes smaller and Al/PTFE were well compounded. Moreover, results showed that the charge formula with milling activated Al/PTFE possessed good propagation reliability in micro linear groove and stronger external expansion capability. These properties were vital for the charge formula to be applied to the complex explosive circuits used for micro shaped charge warhead.
Test analysis anti-shock ability of polyurea coating
Authors: Jia ZJ , Wang S , Cui HL , Hu XB
Published: June 2023

In order to study the impact resistance of the polyurea coating, a 12.7mm ballistic gun was used to launch an impact load to load the target plate, then the velocity of the fragments before and after penetrating the target plate was measured, and the ballistic limit and limit specific absorption energy of the target plate were calculated. At the same time, combining with the coating failure morphology, analyses anti-penetration effect of polyurea protective coating under unit areal density. The research shows that the impact resistance of the composite structure coated with high hardness polyurea coating on the front surface is the best, it has nothing to do with substrate; the impact resistance of the composite structure coated with soft polyurea coating on the back surface is better than that of high hardness polyurea coating, among them, the coating on the back surface will inhibit the impact resistance of composite structures such as fibers that dissipate energy through tensile failure.
Research on test and evaluation method of unmanned ground vehicle information display performance based on fuzzy comprehensive evaluation method
Authors: Zhang Yue , Jiang Haibo , Yu Hai , Hou Xueyi , Gu Chen , Jin Cong
Published: June 2023

This paper conducts research on the test and evaluation method of unmanned ground vehicle information display performance. We build the framework of the performance evaluation system through the analysis of the characteristics of the control terminal. We establish the factor set, evaluation set, weight set and evaluation matrix of the unmanned ground vehicle information display performance and conducts multi-level fuzzy comprehensive evaluation, which provides an effective method for the performance test and evaluation of the unmanned ground vehicle information display.
A Chaotic Pulse Position Modulation Method for Ultra-Wideband Fuze
Authors: Wu Kaiwei , Shi Xiaoshan , Liu Chunhua , Yang Bing , Wang Zhiqi
Published: June 2023

This paper presents a composite chaotic binary sequence that can be used for ultra-wideband(UWB) fuze pulse position modulation, which has good randomness under byte-constrained conditions. The feasibility of this composite sequence for UWB fuze pulse position modulation is verified by hardware implementation. The application of this composite chaotic sequence with good randomness for UWB fuze pulse position modulation will increase the difficulty of recognition by fuze jammer and enhance the radio fuze resistance to active interference.
Rapid positioning test method for cylindrical structure penetration based on machine learning
Authors: Xin Zhang , Bingwen Qian , Bolin Gong , Yutao Hu , Yusong Zhang , Xie Jiang
Published: June 2023

Focusing on the requirements of rapid damage location test for multi-layer steel plates penetration of cylindrical structure in the complex and harsh environment, this paper studies the propagation characteristics of high-speed impact stress waves in steel plates. Also, the measurement effects of impact stress in the near zone of penetration hole are compared with different sensors, so as to select appropriate PZT sensors to measure the velocity of impact stress wave in the actual steel plates. Then the array layout scheme is designed, and the corresponding damage location algorithm is determined. Finally, the deep learning algorithm is used to improve the accuracy and efficiency of damage location.
A method for optimizing the precision of weighted fourier integral transformation algorithm
Authors: Jianhang Sun , Yang Liu , Chunran Sun , Wuwen Lai , Shi Pan , Jun Zhou , Ziheng Cheng , Weidong Hu
Published: June 2023

RCS refers to the radar cross section, which is an important index to reflect the electromagnetic scattering characteristics of the object. RCS measurement is the only method to obtain the real RCS of objects. Since test range often cannot reach the far-field condition for large size object, the near-field-to-far-field transformation(NFFFT) technology is significant in the RCS measurement. The core of NFFFT are different algorithms. Among them, the weighted fourier integral transformation is a universal algorithm, but the data in the aspect angle is segmented in the process, which leads to the discontinuity of the transformation results at the splicing point. This paper introduces a method to optimize the precision of weighted fourier integral transformation algorithm, which can fully suppress the discontinuity of transform results and improve the precision of weighted fourier integral transformation algorithm under the paraxial constraint conditions. Finally, the result of simulation demonstrates the precision and efficiency of this method.
Effect of heat input on microstructure and corrosion resistance of high-nitrogen austenitic stainless steel welded joints
Authors: Li Jianguo , Jia Dongsheng , Zhang Peng , Ma Tao , Lu Zhiyuan , Guo Yunpeng , Wang Lei , Li Zhijie , Li Guoliang
Published: June 2023

In this study, the microstructure and corrosion resistance of high-nitrogen austenitic stainless steel welded joints with different heat inputs were investigated. A high heat input leads to a large width and depth of the fusion pool and a low fraction of δ-ferrite in the weld sea. However, a high fraction of Cr-rich precipitates is formed under a high heat input and low heat promotes the formation of δ-ferrite. Therefore, following corrosion tests, the weld seam suffers severe intergranular corrosion under high heat input and low heat input, and the corrosion resistance of the weld is the highest at a heat input of 6.8 kJ/cm. A high heat input results in a high fraction of Cr-rich precipitates and a random boundary in the heat affected zone (HAZ), which decreases corrosion resistance. Furthermore, corrosion test results indicate that the Cr-depleted area and random boundary are initially corroded, and high heat input decreases corrosion resistance of the HAZ.
Research on The Application of Bracket Loading in Ammunition Distribution
Authors: Li Xin , Wang Li-guo
Published: June 2023

In order to achieve fast and efficient ammunition unitized security, based on the bracket, combined with the supporting self-discharging vehicles, the whole loading and unloading function of ammunition in field conditions is realized, which greatly improves the efficiency of ammunition support. Taking the U.S. Army’s ammunition bracket loading guarantee method as an example, the application of bracket loading in ammunition distribution is introduced. It is proposed that by continuously pursuing the improvement of the assembly tools, the overall loading and unloading exchange efficiency of the bracket loading can be further improved, which in turn speeds up the circulation of ammunition assembly.
A new type of explosive driven fragmentation test device
Authors: Hao Chen
Published: June 2023

An important performance index of explosive is the driving ability of fragment. A new fragment driving test device is proposed in this paper. Taking spherical tungsten fragment as the driving object, the influence of thin shell and thick shell structure on the driving ability of the test device was analyzed combined with TNT and WY-1 explosives. The test results show that the designed fragment driving test device can effectively distinguish the driving ability of different explosives to fragments. And the simulation results are in good agreement with the experimental results. The deviation of fragment driving velocity obtained by the test device is 5 % ~ 8 % compared with that calculated by Gurney model.
RCS Computation and Analysis of a Diamond-shaped Thermal Jacket for Gun Barrels
Authors: Zhang Jie , Gerileqimuge  , Xie Run , Song Yanming , Sun Quanzhao
Published: June 2023

A research on RCS simulations and analysis of a diamond-shaped thermal jacket was carried out, to make thermal jackets on tanks less detectable to known radar observation methods. Based on the principles of radar stealth technology, a diamond-shaped thermal jacket was modeled. The RCS simulation models were established by employing the physical optics method (PO), the monostatic RCS characteristics of the diamond-shaped thermal jacket at high frequency region was investigated, and the major components affecting the radar scattering characteristics were evaluated. The original end part played a major role in the radar scattering characteristics of the diamond-shaped thermal jacket. The RCS simulation of thermal jackets in various shapes, including the cylinder-shaped, the original diamond-shaped, and the diamond-shaped without the original end part are carried out, and a comparative evaluation of the schemes is provided. The results show that trans-shaping the cylinder-shaped model to the diamond-shaped model is a method to effectively reduce the average RCS of the thermal jackets in the frontal and lateral directions, improve the overall stealth performance of tank guns. The work is beneficial for design and evaluation concerning about the shape stealth technology of thermal jackets for gun barrels.
Effect of ramming initial state on band engraving in smooth-bore guns
Authors: Guo C Y , Yang G L , Ge J L , Sun Q Z
Published: June 2023

Most modern tank guns are high bore pressure smooth-bore guns that often use High Explosive Antiarmor (HEAA) projectile in combat. This paper focuses on the coupled smoothbore gun- HEAA projectile system, and analyses the projectile ramming-band engraving process when a tank fires HEAA projectile. First, a finite element mesh model of the coupling dynamics of a large-calibre tank gun smoothbore barrel and HEAA projectile was established, and the band was discretized by using the Smoothed Particle Hydrodynamics (SPH) method based on the Lagrange mesh. Then, the propellant gas pressure acting on the bore and the base of the projectile was defined by ABAQUS user’s subroutine. Finally, the ramming-engraving process simulations were carried out for the ramming residual stress and strain, ramming tilt and different ramming misalignment distances working conditions respectively. According to the simulation results, the effect of different ramming initial states on the band engraving process was obtained. The conclusion provides some reference for the simulation of the band engraving process.
A multi-relaxation-time discrete Boltzmann model of compressible nonequilibrium reactive flows
Authors: Lin Chuandong
Published: June 2023

A multi-relaxation-time discrete Boltzmann model (DBM) is proposed for compressible nonequilibrium reactive flows. The uniform discrete Boltzmann equations are the governing equations of the discrete distribution functions that describe the reactive system. On the right-hand side of the discrete Boltzmann equations, the reaction terms calculated by the inverse matrix method are used to couple chemical reactions and multi-physical fields naturally. Numerical tests show that the DBM is suitable for premixed, non-premixed and partially premixed reactive systems, and is also capable of high-speed compressible reactive flows.
Collapse deformation simulation of metal liner under coupling of multi-physics field
Authors: Wang Y W , Liang H Y , Wang S Y
Published: June 2023

In order to study the collapse deformation mechanism of metal liner under coupling of multi-physics field, the input current was obtained through circuit design and simulation by Multisim. The results show that the peak input current is determined by the capacitor voltage. The coupling simulation of electromagnetic-thermal-mechanical field was carried out by using LS-DYNA software. The influence mechanism of liner on the collapse deformation of the metal liner is analysed. The collapse deformation of liner with cylindrical tip is different from that of traditional liner. The tip of the cylinder is beneficial to utilizing the high pressure in the centre of the cylinder. But the micro-element at the top of the cone collapse to the axis with decreasing velocity along the outer contour of the tip. For the conical metal liner with cylindrical end, the current peak needs to reach more than 2 MA to make the liner obtain sufficient collapse velocity. The collapse velocity of conical metal liner element increases with the decrease of wall thickness, while the collapse velocity of bottom liner element decreases with the increase of cone diameter and cone height.
Calculation and analysis of fluid-solid coupling of rocket sled supersonic water bucket braking process
Authors: Chen Cheng. , Lv ShuiYan. , Zhang Jie.
Published: June 2023

In order to solve the problem of structural damage during the braking process of a rocket sled supersonic water bucket, which affects the braking effect, it is proposed to use the FEM fluid-solid coupling calculation technology to analyze the process of the water bucket entering the water brake. The fluid-solid coupling calculation results show that the limit braking state After the water bucket enters the water brake for 0.06ms, the stress at the entrance position exceeds the yield limit of the material, and the structure is severely deformed and damaged; under normal braking conditions, the water bucket enters the water brake for 0.4ms, the plate at the entrance of the bucket bends, and the structure is seriously deformed at 2ms, The structure is destroyed at 3ms. Using the penalty function fluid-structure coupling method, the numerical analysis of the model water bucket was carried out under two working conditions. Due to the unreasonable design of the bucket, the bucket entrance deformed and destroyed during braking. It is recommended to increase the structural strength of the water inlet side plate.
Influence of Fiber Angle on the Steady State Periodic Response of Annular Sectorial Plates
Authors: Saood Ahmad , Khan Sanan H , Mourad Abdel Hamid I
Published: June 2023

Structural elements in the form of annular sectorial plates are widely used in aeronautical, biomedical, and marine engineering. When these components are exposed to dynamic load, large-amplitude vibrations occur. The vibration response analysis based on the linear strain-displacement relation typically yields a conservative estimate and can be used as a first approximation to the actual solution for thin structural elements. As a result, geometric nonlinearity must be incorporated for the efficient and fail-proof design of such elements. This paper shows non-linear and linear steady-state forced vibration responses of the annular sectorial plates. The governing equations of motion have been solved in the time domain by using a modified shooting method and an arc-length/pseudo-arc length continuation technique at the bifurcation point to obtain the complete response curve comprised of stable and unstable branches. This work investigates the effect of fibre angle on the non-linear steady-state forced vibration response of annular sectorial plates. The strain/stress fluctuation throughout the thickness of the laminated annular sectorial plate is determined to explain why hardening nonlinearity has increased. The cyclic fluctuation of the non-linear steady-state normal stress during a time period at the centre of the top and bottom surface is also provided in relation to the forcing frequency ratio of peak amplitude in the non-linear response. Due to the change in restoring forces, the frequency spectra reveal much increased harmonic involvement along with the fundamental harmonic for all fibre angles.
Demagnetization properties study on NdFeB permanent magnets under impact load
Authors: Liu Tiantian , Yang Guolai , Li Lei
Published: June 2023

Sintered NdFeB materials are more and more widely used in the military field because of their excellent magnetic field performance and cost performance. The demagnetization of materials caused by the impact was discussed in this paper to provide a theoretical basis for the application of NdFeB. Firstly, the experimental platform for the demagnetization of material under impact was built, and the corresponding load of impact was calibrated by using the thin-film piezoelectric sensor. In the experiment, the changes in the magnetic field were converted into an electrical signal that was easy to observe. The curves for the changes of the induced electromotive force and magnetic flux were obtained under different velocities of impact. Then, a new impact demagnetization model was proposed combined with the experimental results and the demagnetization process of sintered NdFeB materials under an external magnetic field. The model was based on the stress knee-point hypothesis and irreversible deterioration hypothesis. Finally, the co-simulation model was established in this paper, and the identified parameters were substituted into the model for numerical calculation. The validity of the model and the accuracy of parameter selection were verified by comparing the calculation results with the experimental results.
A new high energy but low explosion temperature gun propellant component: nitrogen-rich tetrazole derivative grafted nitrocellulose
Authors: Yang C H , Di Z Y , Li X , Wang K W , Hu X L , Ouyang D H
Published: June 2023

In order to apply the high nitrogen-content tetrazole derivatives (TZD), a class of energy materials with great potential, into gun propellant, we propose a novel idea that grafting the acidized TZD onto cellulose and then nitrifying the grafted cellulose to obtain nitrocellulose grafted by TZD (TZDNC). Theoretical predictions suggest that Replacing nitrocellulose (NC) with TZDNC, due to having higher nitrogen-content of TZDNC than traditional NC, can evidently reduce the ablation to gun tube, smoke and flame around muzzle of gun tube. The replacement not only solves the incompatibility of TZD with the other components such as NG, RDX and HMX, but maintains the nearly gun powder power of gun propellant before replacing.
Energetic Characteristics Analysis of Propellants Containing ammonium salts of bis(3-dinitro-1H-1,2,4-triazolyl) borate
Authors: Wang Guo-dong , Ke Yong , Han Rui-lian , Zhang Ling-hao
Published: June 2023

The energy characteristics of HTPB propellant and modified double-base propellants containing bis(3-nitro-1,2,4-triazolyl) ammonium borate are simulated and calculated by NASA’s computer program CEA in the standard state (Pc: P0 = 70:1). The results show that the theoretical specific impulse of the modified propellant is 2539.9 N·s/kg. When the mass fraction of ammonium borate is 80%, the maximum Isp is 2488 N·s/kg, which is 6.5% higher than that of the basic formula, so adding ammonium borate to the propellant is beneficial to improving the overall performance of the propellant. In addition, it is environmentally friendly since it does not contain halogen elements.
Research on the Performance of Deterred-coating DIANP Gun Propellant
Authors: Liu Bo , Ma Fang-sheng , Bian Xiao-yu , Tian De-qing , Wang Qiong-lin , Lv Hao
Published: June 2023

Deterred-coating DIANP gun propellant was prepared by the two-step process called “polymer composite materials deterring and energetic composite materials coating”. The performance of energy and static combustion of deterred-coating DIANP gun propellant was investigated by explosive heat and closed-bomb test. The results show that compared with DIANP gun propellant, the energy of deterred-coating DIANP gun propellant decreased by only about 3.2%, but it had better combustion progressivity and low temperature sensitivity effect. The combustion progressivity of deterred-coating DIANP gun propellant was improved by increasing the content of deterring and coating materials.