bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of Binder on Surface Properties and Coating Effect of TKX-50 Explosive
Authors: Yao L N , Wang C L , Han Z X , Wang H Q , Cao F J , Sheng S X
Published: June 2023

In order to study the surface interaction between binder and TKX-50, fluororubber F2603, ETPE, and BR were adhered to the surface of TKX-50 by the direct solvent volatilization method. The spreading coefficient and adhesion work between the three adhesives and TKX-50 were analyzed by a surficial performance test. The coating effect and safety of TKX-50 coated by three binders were discussed by XPS, SEM, and mechanical sensitivity. The results showed that F2603, ETPE, and BR were adhered to the surface of TKX-50 to form efficient spreading and bonding. The coating effect of F2603 on the TKX-50 was better than that of ETPE and BR, which improved the mechanical sensitivity of TKX-50. The results show that some binders could have positive effects on improving the safety of TKX-50.
Combustion-supporting effect of boron powder on aluminum powder
Authors: Zhang Wei-peng , Guo Hui-li , Huang Ya-feng
Published: June 2023

Aluminum powder is a very important component in both explosives and propellants. Due to the formation of a dense oxide layer Al2O3 at the surface of aluminum, it is very difficult for aluminium powder to react completely, which is the biggest problem at present. For improving the completeness of the reaction of aluminum powder, six kinds of combustion accelerants, ferrocene, ammonium perchlorate, Fe2O3, fluororubber F246, perfluorosurfactant HX-12 and boron powder were selected to study their combustion-supporting effect on aluminum powder by differential scanning calorimetry (DSC) method. The research results show that the six reagents have certain combustion-supporting effects, but the combustion-supporting effect of boron powder is particularly significant. Two extra exothermic peaks appeared as adding small amount of boron powder to aluminum powder. When the content of boron powder is 10 wt % of aluminum powder, the total exothermic heat is more than twice than that of pure aluminum powder FLQT-4. In short, boron powder is a very promising combustion accelerant.
Cook-off Characteristics of Solid Rocket Motor with AP/HTPE Propellant Charge
Authors: He Kai-le , Xue Xiao-chun
Published: June 2023

Conducting thermal safety research on solid rocket motors is a method to effectively improve the battlefield survivability of rockets and missile weapons. Based on the AP-based cock-off reaction mechanism, a 2-D unsteady axial symmetrical model of solid rocket motor is developed. The software Fluent is used to calculate the numerical value of the rocket motor under thermal stimulation conditions of different heating rates. The results indicate that the heating rate of cook-off is negatively correlated with the ignition delay time of the motor, and there is no significant connection between ignition temperature and heating rate. But it is obvious that heating rate has a big impact on ignition position. In the slow cook-off numerical calculation, the initial ignition position appears near the propellant head. And the higher the heating rate, the closer the ignition position is to the propellant head. At rapid heating rate of 1.45K/s, the ignition position appears at the edge of the left end face of the propellant. When rapid heating rate is 1.75K/s or 1.95K/s, ignition position appears at the edge of the right end face of the propellant. At this time, the ignition position will change abruptly.
Review of Evaluation Methods of Underwater Explosion Power of Explosives
Authors: Zhi-yuan Mao , Chao-wei Duan , Hong-wei Hu , Hai-yun Feng , Pu Song
Published: June 2023

Reasonable evaluation of underwater explosion power of explosives is very important for underwater warhead design and other tasks. This paper summarizes the typical experiments of underwater explosion power evaluation, discusses the power characterization methods involved in the tests, and focuses on the explosion bulge test of plate structure and its corresponding dimensionless deflection characterization means. Based on the existing research results, it is proposed to establish a standardized effect target evaluation method, strengthen the research on the relationship between work parameters, explosive detonation parameters and load parameters, and apply the dimensionless deflection method in explosion expansion test to the characterization of underwater explosion power.
Effect of Mg-Al ratio on the combustion and infrared radiation properties of Al-Mg alloy/PTFE composition
Authors: Wang Yi-kai , Zhang Ming-xing , Liu Fei-fan , Tang Jin-shuang , Zhu Chen-guang
Published: June 2023

The effects of Al-Mg alloys with different Mg/Al ratios on the burning rate, combustion products, radiation intensity and specific radiation energy of Al-Mg/PTFE infrared composition were investigated in this paper. The results show that the burning rate of Al-Mg/PTFE decrease with the increase of Al content in Al-Mg alloy. The results of theoretical calculations show that as the Al content increases, the adiabatic combustion temperature first decreases and then increases, taking the minimum value when the content of Al is approximately 58%. In addition, as the Al content of the alloy increases, the particle size of the reaction products gradually become larger, in which the unreacted Al and Al4C3 content increase, while the yield of C and MgF2 become less. The infrared radiation intensity also decreases with the decrease of burning rate. The specific radiant energy of Al-Mg/PTFE reaches the maximum value at 8-14 μm when the ratio of Mg/Al is 30/70 under the combined effect of burning rate and combustion temperature.
Simulation Analysis on Shielding Effectiveness of Rocket Projectile
Authors: Zhao Tuan , Yao Hongzhi , Ji Xiangfei , Li Jiao
Published: June 2023

In order to analyze the shielding effectiveness of the rocket projectile in the electromagnetic environment, the electromagnetic simulation model of the rocket motor was established by using the ANSYS HFSS electromagnetic simulation software, the shielding effectiveness of the rocket projectile motor was calculated, and the influence of the structural charactetristic parameters of the rocket projectile motor on the shielding effectiveness was analyzed, the distribution law of shielding effectiveness with frequency parameters and position parameters were obtained, which provided support for evaluating the electromagnetic environment safety of rockets projectile.
Rapid Optimization Method of Solid Rocket Motor Propellant Under Multiple Load Condition
Authors: zong-tao Guo , qi-xuan Song , zhen-chuan He , xi-bin Luo
Published: June 2023

In order to design a solid rocket motor with a high mass ratio, it is necessary to find out the parameters of the grain shape to meet the structural strength under volume loading fraction condition. A rapid optimization method for a complex grain of solid rocket motors based on parametric modeling and GA-BP is proposed. Based on this, the neural network prediction results are optimized as a function of fitness in GA, and the optimization results show that the maximum Von Mises strain is reduced by 9.8% while the constraints are satisfied.
Effect of FOX-7 on Explosion Performances and Afterburning of HMX-Based Thermobaric Explosives
Authors: Xiao W , Wu X X , Huang K S , Li J , Bi X L , Wan L L , Wang B L
Published: June 2023

In this paper, confined explosions of HMX-based thermobaric explosives in a spherical chamber were studied. The effects of 1, 1-diamino-2, 2-dinitroethene (FOX-7) on the explosion performances and afterburning were obtained by changing its content. The results showed that the composition (HMX/FOX-7) enhanced the total impulse, but its effect on improving the initial energy and quasi-static pressure (QSP) was slight. The aluminum in thermobaric explosives burned incompletely, whereas FOX-7 promoted afterburning of aluminum particles. In addition, the promoting effect was more obvious with the increase of FOX-7 mass score in the composition. In conclusion, when the ratio of HMX to FOX-7 mass fraction in the composition was 3, the thermobaric explosive had low sensitivity and could maintain the energy level of the explosive.
An Investigation of Laser Absorption Enhancement of Energetic Materials Doped with Metallic Nano-Particles
Authors: Diwu Minjie , He Aifeng , Zhao Jia , Chen Jianhua , Zhang Haidong , Lu Feipeng , Jing Bo , Cao Chunqiang
Published: June 2023

The influence onto laser absorption enhancement of energetic materials from doping in metallic nanoparticles was investigated. The FEM analyzation using complex refractive index of Al and Au shows that the doping metal types, the structure of nanoparticles, and the wavelength of electromagnetic waves, takes an influence on the absorption efficiency. The laser ignition experiment was carried, the influence on the ignition properties of pyrotechnics of the energetic material types, the amount of doping particles, and ignition laser parameters were analysed.
Study on Motion Law of Flyer Driven by Micro-Detonator
Authors: Xie Rui-zhen , Liu Lan , Ding Yue-wei , Wang Zhe-jun , Chen Zhen
Published: June 2023

In order to provide design parameters for the micro-initiation train of the built-in MEMS Safety and Arming Device, and solve the reliable transmission problem of the micro-initiation train due to the small charge amount. Based on the structure of micro initiating explosive sequence, the test device is designed in the paper. The photon Doppler Velocimeter (PDV) was used to test the velocity of flyer driven by the micro-detonator, and the influence of the parameters of the flyer, acceleration chamber and charge on the flyer velocity was obtained. That is, when the flyer thickness is the same, the charge density is high and the flyer velocity is high; and the specific charge parameters need to match the specific flyer thickness, so as to obtain the flyer with high consistency and stable flight, and then achieve the ideal impact initiation effect. For the effect of the flyer velocity, the charge density is greater than the charge height, and the charge height is greater than the diameter of the charge.
Effect of ethyl acetate on crystal quality of HMX in the acetone
Authors: Ning Liyuan , Li Lijie , Tao Yuting , Jin Shaohua , Chen Kun , Chen Shusen , Xu Zishuai
Published: June 2023

Crystal quality of explosive affects its processability and safety. The addition of ethyl acetate can effectively improve the surface of HMX crystal in refining process of HMX. The natural volatilization crystallization method was used to study the effect of ethyl acetate content of 0%, 1%, 1.46%, 2.9%, 4.33% and 5% on HMX crystal morphology, crystal form, thermal decomposition properties and crystal quality in acetone-ethyl acetate system. Addition of ethyl acetate less than 4.33%, no change on the morphology and crystal form of HMX, but promotes the β-to δ- polymorphic transition during the decomposition of HMX crystals, and the HMX crystal quality deteriorates. In the research range, when the addition amount reaches 5%, the crystal quality is improved.
Design and mathematical modeling of a pyrotechnically actuated water inlet device
Authors: Li Shuai , Wang Yunpeng , Xu Xiangdong , Wang Wei , Gao Yilong , Wang Wenwei , Chen Guoguang , Wang Duan
Published: June 2023

Pyrotechnically actuated devices(PADs) rely on combustion of energetic materials to achieve various functions and are widely used in aerospace fields. In this paper, based on the basic principle of the PADs, a piston-type water inlet device is designed, which can make underwater weapon sink into the seabed to self-destruct when there is an abnormality, and prevent the weapon from accidentally acting or being captured. A segmented mathematical model was established to study the kinematic characteristics of the device, and the functional experimental was carried out. The results show that the water inlet device works reliably and can be applied to a variety of underwater weapons. The mathematical model can predict the performance parameters of the water inlet device during the movement process, providing support for the engineering application and optimal design of the device.
Study on cutting performance of aramid fiber weaving material by linear shaped charge
Authors: Liu R Q , Wang P , Yu R , Yu W Q , Li R , Si X N , Shang X R
Published: June 2023

In order to realize the precise fuze-warhead matching, the parachute belt needs to be cut to realize the separation of projectile and parachute. Combining experiment and numerical simulation, study on cutting different layers of aramid fiber weaving parachute belt with linear shaped charge are carried out. The results show that the copper linear shaped charge with linear density of 15 g/m can reliably cut 6 layers of aramid fiber weaving material, and the cross section of parachute belt are neat. EXPLO5 software is used to calculate the JWL equation of state parameters of bulk RDX with different densities. And orthogonal anisotropic softening model proves to be successful in numerical model to simulate the cutting process of aramid fiber weaving materials by linear shaped charge. The number of cutting layers is in good agreement with the experimental results. On this basis, simulations of the cutting performance of the explosive standoff and linear density are carried out. The results show that with charge density of 1.4 g/cm3, the cutting performance is the best with the explosive standoff of 1 mm, which can cut 7 layers aramid fiber weaving material. The maximum cutting depth increases almost linearly with the increase of charge density.The research in this paper can provide theoretical support for cutting flexible aramid fiber weaving materials by linear shaped charge.
Incorporating of BCHMX in traditional plastic explosives
Authors: Elbeih Ahmed , Hussein Ahmed K. , Zeman Svatopluk
Published: June 2023

cis-1,3,4,6-tetranitro-octahydroimidazo-[4,5-d]imidazole (BCHMX) was investigated as an energetic filler with three different plastic explosives based on three matrices: C4 matrix, semtex10 matrix and EPX matrix. The original plastic explosives, composition C4 including RDX (1,3,5-trinitro-1,3,5-triazinane), Semtex 10 explosive based on PETN (pentaerythritoltetranitrate) and plastic RDX-silicone were included for comparison. Sensitivity and performance parameters were studied. Differential thermal analysis (DTA) was investigated to determine the thermal behavior. The sensitivities to friction and impact were evaluated and the explosive characteristics were determined by measuring the detonation velocity and determining the performance by the ballistic mortar test. The detonation parameters were also calculated for all samples using EXPLO5 code. By comparing the results obtained experimentally or by calculation, it is clear that the application of BCHMX in the used plastic matrices increases the performance and detonation characteristics in comparison with the original plastic explosives. Regarding to the results of sensitivity, thermal stability and performance tests, replacing PETN explosive by BCHMX in semtex matrices seems to form promising plastic explosive and needs further studies. On the other side, the performance of BCHMX-C4 is higher than that of composition C4.
Theoretical study on structure and properties of borate ester energetic compounds
Authors: Guo-dong WANG , Su-ming Jing , Guo-qing Liu
Published: June 2023

The potential advantages of energetic boron esters in the application of energetic materials were analyzed. Based on the synthesis feasibility analysis, 10 kinds of tetrazolium energetic boron esters were designed. The geometric structure, density, enthalpy of formation and impact sensitivity of 10 energetic boron esters were calculated by using density functional theory. The detonation parameters were calculated by using Explo5 program. The results show that the density of 10 compounds is between 1.74 ~ 2.18g/cm3, the detonation velocity distribution range is 7675.92 ~ 9209.45km/s, and the detonation pressure distribution range is 26.75 ~ 36.18Gpa. Among them, tris (5-difluoroaminotetrazole) borate has the best energetic properties and has a good application prospect in propellant bonding agent and pyrotechnic agent.
Scaled-up production and quality controlling techniques of energetic cocrystals: challenges and prospects
Authors: Li H J , Zhang Z , Ma N , Chen S , Li H J , Yang L , Liang C Y , Yi J H , Zhao F Q
Published: June 2023

Cocrystallization techniques have become extremely important methods for obtaining novel high-energy insensitive energetic materials, and it has attracted great attention for the development of high-energy explosives and propellants, etc. in recent years. Several scale-up cocrystallization techniques including solvent-nonsolvent, semibatch reaction, bead milling, and spray drying methods et al. have been applied for obtaining the energetic cocrystals, and the preparation processes of these methods were also shown. The types and quality of raw materials and solvents, the synthetic times, morphology, and size of these cocrystals were described and compared by using different synthetic techniques in the review. Moreover, the principle, advantages and disadvantages of scale-up preparation methods were shown. More importantly, the preparation efficiency, the ratio between the quality of raw materials and the volume of solvent, and yield of different methods were also exhibited and discussed, which can provide key information and experiences for the future application of the materials. Finally, future research trends are suggested from different perspectives involving the formation mechanisms in the preparation process by using intermolecular interaction simulation, experimental study, and thermodynamic calculations, the optimization of traditional scale-up techniques, and the exploitation of novel methods for the energetic cocrystals.
The characteristics and mechanism in combustion extinguished process based on self-extinguished solid propellants
Authors: Haiyang Yu , Limin Wang , Lei Huang , Xing Zhou
Published: June 2023

With the addition of the quaternary ammonium salt used as surfactant, a self-extinguished solid propellant was prepared. The combustion performance, extinguished burning surface and thermal analysis of the self-extinguished propellant were studied. The quaternary ammonium is a key point to the extinguished process in combustion because of the influence in interface between oxidizers and binders. The similar critical pressure of extinguished and the inflection point of the pressure exponent indicated that the mechanism in combustion extinguished process was also related to the reaction process of oxidizers.
Host-Guest Energetic Materials : A Possible Combination between LiN5 and 12-Crown-4
Authors: Zhang Xiaopeng , Hou Tianyang , Xu Ze , Xu Yuangang , Lu Ming
Published: June 2023

Attempts are made to gain possible host-guest energetic materials of LiN5 and 12-crown-4. The cyclo-N5
− ring breaks up into N3
− duing the experiment and we finally achieved the combination between LiN3 and 12-crown-4, which was confirmed by single-crystal X-ray diffraction. The experimental results are further explained by theoretical calculations. More importantly, a new strategy, through size matching between crown ether compounds and metallic cyclo-N5
− compounds to get the combination, is presented for trapping of pentazolate rings in this paper.
The preparation of lead oxide / carbon nanotubes complex and its catalytic performance
Authors: Li J Z , Wei A W , Zhang Y J , Qu B , Zhang G F , Zhong F X , Xie Z Y , Tang Q F
Published: June 2023

The introduction of carbon nanotubes (CNTs) in the preparation of nano-lead oxide (PbO) can effectively solve the problem of easy agglomeration of nano-lead oxide. This study used concentrated nitric acid and concentrated sulfuric acid mixed acid (volume ratio 1:3) to oxidize carbon nanotubes at 90 °C temperature for 0.5 h. Using and the oxidized CNTs as carriers, Pb(OAc)2 · 3H2O as precursor, concentrated ammonia as a precipitator, PbO/CNTs complexes were prepared by chemical precipitation. Lead content of PbO/CNTs complex, determined by Complexometry, was 59.80 %(wt%), XRD and XPS characterizations revealed that the catalyst components of the prepared complex were mainly nano-sized PbO, And a small amount of lead, SEM and EDX characterization revealed PbO with the particle size between 20 m-200 nm had been successfully Loaded onto the CNTs surface, TEM show that the PbO and CNTS retained the original lattice, a spot of lead oxide was found inside the tubes. The thermal decomposition effect of PbO/CNTs on AP, RDX, HMX was evaluated by DSC, and the catalytic effect on AP and RDX was found to be obvious.
Study on impact damage mechanism of gun propellant based on bonding contact model
Authors: Zhang R H , Zhang Z Z , Liu J H , Zhao B M , Zhao H L
Published: June 2023

As the main launch energy of barrel weapon, the dynamic mechanical properties of gun propellant is very important to evaluate the launch safety. Through the transverse drop hammer impact damage test at room temperature and the initial dynamic vivacity ratio test of the propellant, the crack growth law and the fracture degree of the damaged propellant were obtained separately. Based on the Hertz-Mindlin bonding contact model, the discrete element mechanical model of the rosette 19-hole gun propellant was established, and the transverse drop hammer impact damage simulation was carried out. The damage mechanism of the bonding contact model and the fracture degree of the damaged propellant were acquired, which were also verified by tests. The results show that the bonding contact model can accurately describe the impact damage law of propellant. The research results of this paper can be used to predict the abnormal chamber pressure caused by fracture of propellant, provides a research means for mechanical property evaluation of 3D printing gun propellant, and lays a theoretical foundation for quantitative evaluation of launch safety.
Study on the compression energy absorption characteristics of 3D printed PLA and PLA-Cu materials
Authors: Qing Ji , Zhijun Wang , Yifan Wang
Published: June 2023

In order to study the static compression mechanical properties and energy absorption characteristics of 3D printing polylactic acid (PLA) and copper powder filled polylactic acid (PLA-Cu) materials, quasi-static compression tests were carried out at room temperature using CMT5105 microcomputer controlled electronic universal testing machine. The results show that the stress-strain curves of the two materials show the compression characteristics of porous materials, and have typical three-stage characteristics. The compression bearing capacity of PLA-Cu materials is significantly higher than that of PLA materials. When the strain is 80 %, the energy absorption per unit volume of PLA material can reach 78.27 MJ / mm3. After adding copper powder, the energy absorption per unit volume of PLA material can be increased by 51.7 %, indicating that 3D printing products have excellent impact resistance and buffer energy absorption characteristics.
Effect of explosive shock on the mechanical property and energy release characteristics of an Al/Ni reactive material
Authors: He Y , Xu T , He Y , Tian W X
Published: June 2023

Reactive materials applied to warhead fragments or charge liner will be driven by strong detonation, so their mechanical behavior and energy release characteristics will be affected to a certain extent. In this paper, dynamic and static mechanical tests and impact initiation experiment were carried out on the detonation-loaded Al/Ni reactive material. Compared with materials that have not subjected to explosive shock, it is found that Al/Ni materials have better mechanical strength after explosive shock. Meanwhile, the impact-initiated energy release efficiency of the material is lower, when loaded with 14.76GPa, 21.79GPa and 28.84GPa, the reaction degree decreased by 26.6%, 78.8% and 80.5% respectively. Due to the incompatibility of elastic modulus and melting point between aluminum and nickel particles, the nickel particles move and aggregate in the aluminum matrix during shock loading. The pores appear at the particle boundaries, and gradually expand into cracks. The research results show that the original material parameters cannot be used to judge the working conditions of the reactive materials, and the explosive conditions of the loading are external factors that requires additional consideration.
Research on PTFE/Al reactive jet formation of shaped charge
Authors: Wang Yan-xin , Xie Zhi-yuan , Xu Rui-ze , Xiao Jian-guang
Published: June 2023

During the PTFE/Al reactive shaped charge jet formation, the burst wave generated by the explosion of the explosive is sufficient to achieve the ignition conditions of the reactive materials (RMS). As a result, the RMS will react, resulting in an energy loss from the reactive jet. In order to research the forming features of PTFE/Al reactive jet and the energy loss during the jet formation, a PTFE/Al reactive liner with a diameter of 74 mm was prepared and an X-ray pulses photography experiment was performed on the jet formation. And the parameters of Johnson-Cook constitutive model of RMS were obtained through quasi-static experiments and Hopkinson pressure bar experiments. The jet formation were simulated, and the AUTODYN secondary development technology was used. The results show that the secondary development technology can intuitively show the reaction of the active material during the jet formation. The PTFE/Al reactive jet is less cohesive, its jet diameter is thicker, and the morphology is divergent. The reactive materials reacted during the PTFE/Al reactive shaped charge jet formation. And during the reactive jet formation, the inner layer of the liner collided. Therefore, most of the chemical reactions occur inside the reactive jet.
Formation behavior of hypervelocity reactive compostite jet
Authors: Li P L , Zhang H Y , Bie H Y , Zheng Y F
Published: June 2023

A kind of hypervelocity reactive composite liner shaped charge(HRCLSC) structure is designed by combining tungsten additional liner and reactive cooper composite liner. The formation behavior of hypervelocity reactive composite jet (HRCJ) is studied by numerical simulation method. The velocity distribution and detonation wave propagation of HRCJ are compared with that of normal reactive composite jet (NRCJ), which proves that HRCJ has better formation performance. The influence of liner structure on the formation performance of HRCJ is investigated by changing the cone angle of the composite liner and the thickness of the additional liner, the results show that the cone angle of the liner has little effect on jet head velocity while the thickness of the additional liner has great effect on jet velocity. When the thickness of the additional liner is 5mm and the cone angle of the composite liner is 60°, the effective mass utilization rate of the jet is better, and the head velocity reaches maximum.
Numerical modeling and verification of reactive projectile impacting plate
Authors: Zhang Jiahao , Zhao Hongwei , Zhou Sheng , Yu Qingbo
Published: June 2023

The penetration of reactive projectile into target is an extremely complex thermomechanical coupling process, and most of the researches reveal this coupling mechanism by means of experiments. In this paper, based on the finite element simulation software ANSYS/LS-DYNA, using IGNITION_ANG_GROWTH state equation and Null constitutive model, the process of reactive projectile penetrating target is numerically modeled, and the numerical simulation model is verified by ballistic impact test. The test results are in good agreement with the simulation results. Further, according to this numerical simulation model, the ballistic limit of reactive projectile penetrating target is studied. The results show that the IGNITION_ANG_GROWTH state equation and Null Constitutive model can be used to calculate the mechanical and chemical coupling responses of the reactive projectile in the process of penetration plate effectively based on the SPH algorithm. This provides a new method to study the reactive projectile penetration-explosion coupling process.
Study on jet formation and penetration behaviour of shaped charge with reactive material composite liner
Authors: He Suo , Xiang Jingan , Cai Yiqiang , Guo Huanguo
Published: June 2023

The shaped charge with reactive material composite liner could not only meet the requirement of the after-effect damage behavior, but also achieve a deeper penetration capability. Based on the platform of AUTODYN-2D code, the jet formation characteristics of the reactive material-titanium liner shaped charge and its penetration behavior to multi-spaced plates were studied. Numerical simulations showed that with increasing of the detonation pressure of explosive, the tip velocity of the composite jet and its penetration capability increased, but the reactive material liner was subjected to the higher pressure and the temperature rise within the elements was larger. In addition, the influence of the standoff and the protective steel block thickness on the penetration behavior of the reactive composite jet was investigated. As the standoff increases from 0.5 CD to 3.0 CD, the penetration capacity of the composite jet increased, but the mass of reactive materials follow-in the spaced plates decreased. With increasing of the steel block thickness, the penetration capability of the reactive material-titanium jet and reactive material follow-in behavior decreased gradually.
A numerical simulation approach for the residual prestress of composite barrel with non-round section of railgun with tension winding
Authors: Yin Dongmei
Published: June 2023

In order to obtain the distributions of residual prestress of the filament wound composite barrel with non-round section for railgun caused by the winding tension, a new numerical approach is provided. Based on the idea of considering the fiber bundles as the main load-bearing material for each winding layer, the loading of the initial winding tension in the winding process can be simulated through loading the initial tensile stress of the fiber bundles in fiber direction of the winding layers’ elements. Firstly, combing with the element birth and death technology, a three dimension finite element model for a hybrid filament wound cylinder with metal liner is established to simulate its residual prestress caused by winding tension. Its results are compared with the ones obtained by the theoretical model, which verifies that this numerical simulation method is reliable to some extent. Then, this numerical simulation method is adopted to analyze the residual prestresses of the filament wound composite barrels with non-round section for railgun, which are under three different winding tension control modes respectively. The results can provide some references to the initial design of the filament wound composite barrel with non-round section for railgun.
Preparation, structure and mechanical properties of SiC particle reinforced titanium-aluminum layered composites
Authors: Yang Lin , Yang Di , Sun Mengyong , Tong He , Wang Shuai , Guo Chunhuan
Published: June 2023

Ductile Ti in Ti/Al3Ti laminated composites only improves the plasticity of Al3Ti, but does not increase the strength of Al3Ti essentially. The silicon carbide particles have excellent properties such as low density, low expansion, high hardness, high stiffness, high elastic modulus and isotropy, which can be used in layered composite Ti/Al3Ti to further improve its strength. In this paper, the SiC particle-reinforced Ti/Al3Ti laminated composites were prepared by ball milling, and its microstructure was characterized by scanning electron microscope(SEM), energy dispersive spectrometer(EDS) and other testing methods, and the phase was calibrated by X-ray diffractometer. The physical and mechanical properties were tested, and the fracture mechanism of SiCp-Ti/Al3Ti laminated composites was analyzed.
Research on the Effect of Modulation Ratio on the Firing Performance of Reactive Bridge Films
Authors: Yu Ke-Xin , Ren Xiao-Ming , Wang Zhuo , Shi Min-Ke , Liu Hong-E , Chu En-Yi
Published: June 2023

In this paper, we mainly design two modulation ratios of Al/Ni reactive films, prepare TaN@(Al/Ni) by MEMS (Micro-Electro-Mechanical Systems) technology, and conduct firing experiments using capacitive firing. The experimental results show that the modulation ratio has a large effect on the firing performance of reactive bridge films, and the action process of the reactive film can be clearly observed by high-speed photography.
An image restoration method for motion-blurred objects
Authors: Ge L , Dou L
Published: June 2023

In military applications, the motion of high-speed objects usually causes motion blur in images, which makes it difficult to detect objects. We propose an image restoration method based on the line features and the degradation process of motion-blurred images. By analysing these features, we can estimate the motion state of the target and restore the images. The images processed by this method can get better performance in tasks like object detection and object tracking.
Acousto-optic Multi-source Information Fusion Algorithm for Outdoor Pedestrian Detection
Authors: Su Zilong , Feng Hengzhen , Zhao Fei , Xuan Weikun
Published: June 2023

The inefficiency of traditional rescue methods is a serious threat to the life and health of outdoor people in distress, so the research on pedestrian identification for outdoor rescue has important theoretical significance and application value. In order to solve the problem of low probability of recognition based on signal information in traditional methods, an outdoor pedestrian recognition model based on acousto-optic information fusion is constructed. Considering the characteristics of the information source, the directional gradient histogram of the infrared image and the Mel Cepstral Coefficients of the acoustic signal are selected as the factors affecting the recognition probability, and the pedestrian recognition probability correlation equation is deduced; Based on the improved D-S evidence theory of fuzzy system, a pedestrian recognition method based on infrared image and sound signal is proposed, and the mapping relationship between two kinds of information sources and detection probability is established to improve the pedestrian recognition probability. The hardware-in-the-loop simulation results show that the pedestrian recognition probability of fusion of infrared image and sound signal is higher than that of single information, which provides an efficient and reliable method for outdoor rescue.
A Detection Technique of Laser Pyrotechnics Sealing Quality Based on 3D Microscope with Super Depth of Field
Authors: Zhao Jia , He Aifeng , Jing Bo , Cao Chunqiang , Diwu Mingjie , Lu Feipeng
Published: June 2023

Glass sealing is one of the key technologies in the assembly of laser pyrotechnics, the sealing quality will significantly affect the action performance of pyrotechnics. Therefore, it is necessary to detect the sealed laser pyrotechnics and eliminate unqualified products to improve the reliability of pyrotechnics. 3D microscope with super depth of field can realize stereoscopic observation, real-time measurement and high-definition imaging. It can be used to observe the microscopic morphological characteristics that cannot be directly seen by naked eye, and can also be used to carry out dimensional measurement. Thus, it has a desirable application prospect in many fields. In this paper, a quality detection technique of laser pyrotechnics sealing based on 3D microscope with super depth of field is explored, and the sealing effect of laser pyrotechnics is tested. This technique can be used to improve the glass sealing technics and enhance the reliability of laser pyrotechnics.
Infrared fiber bundle image super-resolved based on computational imaging
Authors: Wang Bowen
Published: June 2023

As the representative of flexibility in optical imaging media, in recent years, fiber bundles have emerged as a promising architecture in the development of compact visual systems. Dedicated to tackling the problems of universal honeycomb artifacts and low signal-to-noise ratio (SNR) imaging in fiber bundles, the iterative super-resolution reconstruction network based on a physical model is proposed. Under the constraint of solving the two subproblems of data fidelity and prior regular term alternately, the network can efficiently “regenerate” the lost spatial resolution with deep learning. By building and calibrating a dual-path imaging system, the real-world dataset where paired low resolution (LR) - high resolution (HR) images on the same scene can be obtained simultaneously. Numerical results on both USAF target and complex target objects demonstrate that the algorithm can restore high contrast images without pixilated noise. On the basis of super-resolution reconstruction, compound eye image composition based on fiber bundle is also realized in this paper for the actual imaging requirements. The proposed work is the first to apply a physical model-based network structure to fiber bundle imaging in the long-wave infrared band, effectively promoting the engineering application of thermal radiation detection.
Design of the Automatic Gain Control Device in the Laser Seeker
Authors: Lang Bo , Huang Qiang , Mi Changwei , Liang Yuan , Bing Liang , Zhang Xiaoliang , Xue Lu , Wang Ao
Published: June 2023

The change of the laser echo energy received by the laser seeker during detection is too large, it is easy to saturate the input voltage of the signal processing circuit, which resulted the laser guided bombs lost the target. In this paper, an automatic gain control device for the laser seeker based on FPGA control is designed. This device is suitable for low-cost laser guided bomb because of simpleness and applicability.
Sparsely sampled Fourier ptychography in diffuse reflection
Authors: Li Sheng
Published: June 2023

Fourier ptychography microscopy combines the idea of aperture synthesis, which enables the synthesis of multiple low-resolution images in the frequency domain to achieve large field-of-view and high-resolution imaging results. The Fourier ptychography imaging technique applied to the field of far-field diffuse reflectance imaging needs to consider the impact of diffuse reflectance speckle formed by the object’s rough surface on the imaging results. Therefore, far-field diffuse reflectance Fourier ptychography often requires more than microscopic imaging of low-resolution images to achieve super-resolution. In response, we design a sparse sampling method that can reduce the number of required low-resolution images to one-fourth of the original sampling, and does not affect the imaging resolution. Experimental results show that our method can significantly improve imaging efficiency and achieve super-resolution far-field imaging with fast sampling.
3D observation instrument for pathology tissues
Authors: Liang Zhongwei , Mu Shuang , Hu Yan
Published: June 2023

Pathology telemedicine uses digital data of pathological samples to acquire technical support from sophisticated remote experts, aiding cancer diagnosis in less developed regions. In this paper, we propose a color 3D observation system composed of three cameras and a digital projector, achieving complete range 3D imaging of pathology tissues. A new phase mapping method for the projector calibration is proposed by locating the geometric centroid of the checkboard’s white squares, avoiding the center positioning error of traditional circular markers introduced by perspective distortion. A denoising method successively using amplitude modulation judge, phase monotonicity check, and phase abruptness constraint is proposed, which facilitates obtaining clean 3D point clouds.
Edge detection algorithm for noisy remote sensing image using directional filter
Authors: Zhang He , Zhang Kaimin , Wang Fan , Qian Weixian
Published: June 2023

Remote sensing image edge detection is the basis of remote sensing image registration and recognition. In view of the noise formed in the process of remote sensing image acquisition, a new edge detection algorithm based on directional filter is proposed to improve the accuracy of remote sensing image registration and recognition. The directional filter is based on wavelet transform denoising, and three main features including scale, direction and shape of wave are introduced. The target edge can be identified more accurately in the noisy image by the directional filter, and the edge detection result image is obtained by binarization segmentation and non-maximum suppression. Through experimental comparison with other denoising detection algorithms, more accurate edge detection results can be obtained, and there are obvious advantages in operation efficiency.
Infrared Small Target Detection Based on Isolation Constraint Under Complex Background
Authors: Wang Fan , Zhang He , Qian Weixian
Published: June 2023

In the development of infrared search and track (IRST) system, small target detection in complex background is a challenging task due to the low signal-to-noise ratio (SNR) of small targets and interference of irregular clutter. In this paper, a detection method based on isolation constraint is presented. Firstly, the suspected region with certain contrast is obtained by multilayer gray difference (MGD). Then we calculate the isolation index of the suspected region using the eigenvalues of Hessian matrix of the raw image to suppress the irregular clutter. In order to get accurate size of the target, a local scale estimation method is proposed. Experiment results demonstrate that the proposed method is accurate and robust, and superior to baseline methods in signal-to-clutter gain (SCRG) and receiver operating characteristic (ROC) curve.
Recent advances for water-stable metal-organic frameworks (MOFs)
Authors: Cao Xin , Li Haijian , Yi Jianhua , Zhao Fengqi , Hao Yucheng
Published: June 2023

Metal-organic framework (MOF) compounds have been widely studied and explored for many years due to their diversity of structure and composition. It is a new kind of framework material because of its high specific surface area, high porosity, and adjustable pore structure and internal environment. It has unlimited development prospects in gas storage, separation, catalysis, chemical sensing, and other related fields. Therefore, MOFs have attracted great and extensive attention. This paper mainly summarizes MOFs materials with good water stability, and stability of MOFs compounds under various harsh environmental conditions was analyzed, and the synthetic method and properties of these MOFs materials were summarized. In conclusion, this paper for the summary of the water-resistant MOFs compounds is helpful to provide a good guide to finding or creating other novel water stability MOFs functional materials.
Ship Classification Based on Density Features in SAR Images
Authors: Yang Longshun , Guo Pengcheng , Wang Jingjing , Feng Chao
Published: June 2023

Ship classification in SAR images has attracted much attention by researchers. In this paper, a SAR target classification method for three commercial ships (container ships, bulk carriers and oil tanker) is proposed by analyzing their scattering features. Firstly, the ship slice is preprocessed to obtain the binary image, from which the density features can be extracted, which describing the ship scattering point distribution. Finally, the support vector machine (SVM) classifier is applied to classify these three types of commercial ships. The experimental results show that the classification accuracy of structure feature and strength feature is low, while the proposed density feature can reach 80% for three types of ships. The combination of structure features and strength features with density features can improve the classification accuracy. Combining the three features has the best classification performance.
Siamese Network with multi-scale fusion attention for Visual Tracking
Authors: Shangjie Xue , Wenjin Yao , Wenjun Yang
Published: June 2023

The existing trackers based on the Siamese network have poor tracking robustness in the face of complex situations such as target occlusion, rapid target movement and scale changes. To address this problem, we propose a new tracking framework based on the Siamese network with multi-scale fusion attention. The algorithm proposed in this paper increases the receptive field of the last two layers of the backbone network, strengthens the ability to capture target information, and outputs the last three layers of the backbone for feature fusion. We add an improved visual attention model, and the multi-scale channel attention model is used for the first time in this work, so as to strengthen the long-range dependence of feature information and the learning of channel attention, so that the network can select better salient features of the target. In this paper, to avoid to generate complex hyper-parameters for the target candidate frame and speeds up the training speed of the network, we introduce an anchor-free classification and regression network model. The experimental evaluation conducted on the OTB100 and VOT2016 datasets shows that the algorithm in this paper has good robustness in the face of challenges such as target occlusion, rapid target movement and scale changes, and effectively improves the accuracy of our algorithm.
Enhance Terahertz Image Resolution via Complex-valued convolutional neural networks
Authors: Hu Nairui , Qi Feng , Li Yufeng
Published: June 2023

Terahertz imaging technology is widely used in nondestructive testing (NDT), human security inspection, far-field imaging systems, and so on. Improving image resolution is always a topic of discussion. For visible image and image super-resolution, the convolutional neural network (CNN) has achieved a better improvement effect than the traditional algorithm. Compared to optics, it is quite feasible to gain both the amplitude and phase information in THz imaging, the Complex-valued convolutional neural network (CV-CNN) is better suited for the field of terahertz imaging than the real-valued neural network. In this paper, A lightweight complex-valued neural network is constructed which enhances terahertz imaging in a vector network analyzer (VNA) imaging system. Compared to CNN, CV-CNN has a better peak signal-to-noise ratio (PSNR) and structural similarity (SSIM), and it is significantly less vulnerable to overfitting. Phase information can be used well at the same time, which is impossible for CNN. The network is trained using the MNIST dataset and verified by using simulated and measured data obtained from a 200Ghz imager.
Numerical study on damage effects of segmented reactive-core penetrator impacting double-layer steel targets
Authors: Qi Y X , Jiang C L , Wang Z C , Hu R , Xu W Y , Mao L
Published: June 2023

Reactive penetrator has stronger damage effects due to the combination of penetration and blasting. In this paper, numerical simulations are carried on by LS-DYNA to understand the penetration mechanism of a new type of segmented reactive-core penetrator. The primary core and secondary core are made of W/Zr reactive alloy and PTFE/Al reactive composite respectively, which are coated by a steel shell. Different from the Penetrator with Enhance Lateral Effect (PELE), the penetrator in this investigation performs a “self-sharpening” behaviour due to its high-density primary core and prefabricated groove. It is shown that the impact velocity of the penetrator has an influence on the fragmentation of targets, and there is a good balance between penetration ability and chemical reaction.
Terahertz near-field imaging of graphene disks
Authors: Xu Xingxing , Zhang Xiaoqiuyan , Zhang Tianyu , Liu Shenggang , Hu Min
Published: June 2023

Due to the weak power of Terahertz sources, metal tips are often used to enhance the signal intensity of the Terahertz scattering scanning near-field optical microscope (THz s-SNOM). However, while enhancing the near-field, metal tips also affect the field distribution on the sample surface. In this paper, a home-built 97.8GHz sub-Terahertz near-field imaging system was used to image graphene disks with dozens of microns in diameter. It was found that the field distribution was significantly different from that without the tip, and was related to the incident direction of the terahertz wave.