bluuebunny/crossref_metadata_2025_split huggingface dataset:
Adaptive bionic joint base on the flexibility feature of ostrich intertarsal joint
Authors: Zhang R , Cao Q Q , Ling L , Kong L X , Wang C , Su B , Wen L G , Li J Q 
Published: July 2020

Abstract
The joints of traditional foot robots are generally designed as power-driven articulated rotary motion, but this design has some problems such as poor flexibility and adaptability. To optimize joints, this paper selected the African ostrich intertarsal joint which could move at high speed in complex terrain as a biomimetic prototype. Based on the motion acquisition and reverse engineering three-dimensional reconstruction of the intertarsal joint, a rope-driven spherical sub-bionic joint was designed. The angle curves of the bionic joints under different ground conditions were obtained through the hard ground and the motion tests of three different softness sands (medium with different particle sizes). Results showed that the proportion of the vacant period was 35%, 49%, 62% and 63% when the bionic joint moved on the hard ground and three soft grounds (the particle size particles are arranged from large to small),. The range of variation gradually becomes larger, similar to the variation trend of the intertarsal joint during ostrich locomotion. The bionic joint was able to absorb joint impact through the relative slippage of the joint surface and expansion/contraction of the rope, and maintain flexibility when passing through different degrees of softness.
Study on application of open source intelligence from social media in the military
Authors: Ju Y , Li Q , Liu H Y , Cui X M , Wang Zh H 
Published: July 2020

Abstract
With the gradual popularization of information technology and network technology, various types of open source information, especially social media information, have shown an explosive growth trend. Social media intelligence not only possesses ideological and value-level values, but also directly serves military defense. It will help stimulate open source intelligence to play a huge role in combat operations that combining communications and psychological knowledge to explore and exploit frontier technologies in artificial intelligence, such as machine learning and data mining, and conducting research on social media big data collection, analysis, mining, and prediction technologies. This paper focuses on the preliminary analysis of the application of open source information such as social media in the field of military intelligence.
Revelation of catalytic reduction process affecting the morphology and properties of CNTs/carbon fabrics and their composites
Authors: Lu R J , Zhong T , Wu H L , Miao C , Bai L H , Yuan W , Wang C G 
Published: July 2020

Abstract
Carbon nanotubes/carbon fabrics and their reinforced resin matrix composites were manufactured by chemical vapor deposition and molding method, respectively. Different catalytic reduction processes with different catalyst types and reduction temperatures had different effects on their morphology and properties. It was found by a series of characterization methods that the catalytic activity of the bimetallic catalyst was higher than that of the single metal, and the surface uniformity of CNTs catalyzed by Fe-Co was the best. When the reduction temperature reached the growth temperature, the uniformity of CNTs and the interlaminar shear strength of composites increased obviously. The influence mechanism of these parameters was discussed in depth, which provided a fundamental engineering basis for understanding of catalytic reduction process, optimizing of CNTs growth process and the application of high-performance composite materials.
Structural designation and mechanical properties of TiNi/Ti2Ni laminated composites
Authors: Jia C , Xiong Z P , Liu Z , Cheng XW 
Published: July 2020

Abstract
TiNi/Ti2Ni laminated composites were fabricated using hot isostatic pressing (HIP) furnace together with structural designation by the control of Ti and Ni foil thicknesses. During HIP processing, Ti reacts with Ni, leading to the formation of softer TiNi and harder Ti2Ni. Through adjusting the thickness ratio of Ti and Ni foils, the ratio of TiNi and Ti2Ni fraction can be controlled. Hard-soft-hard, soft-hard-soft and hard-intermediate-soft laminated composites were designed, where hard layer was made by 50 μm Ti and 20 μm Ni, soft layer was made by 40 μm Ti and 20 μm Ni, and the intermediate structure between hard and soft ones was made by 45 μm Ti and 20 μm Ni. The mechanical properties were characterized using uniaxial tension, uniaxial compression, single edge-notched beam and split-Hopkinson pressure bar. The results show that all three laminated composites have compression strength of 1690 ∼ 1853 MPa and fracture toughness of 27.2 ∼ 37.9 MPa• m1/2 due to the same constituents of TiNi and Ti2Ni. However, the soft-hard-soft structure shows the best response under high strain rate because it was fractured into larger pieces while the other two structures were fractured into smaller pieces together with smaller fracture strain.
Numerical analysis of railgun muzzle flow field with multi-component plasma
Authors: Gao Y , Ni Y J , Li B M 
Published: July 2020

Abstract
The railgun is a new concept launching weapon with high supersonic launching capability. Under the acceleration of Lorentz force produced by the discharge of strong pulse power source, the projectile leaves the muzzle in hypersonic speed. Due to the severe friction of armature in bore and the phenomenon of transition ablation, metal vapor is produced in the interior ballistic process and rush out of muzzle along with armature’s movement. Because of the open structure at both ends of the railgun, the pressure in the bore is much lower than the standard atmosphere, so there exists the phenomenon of muzzle gas backflow. In this paper, the coupled interface method and the multi-component plasma model are used to simulate the movement of metal vapor in the process of projectile moving out of the bore. The pressure boundary conditions and gas composition in the muzzle region of the simulation results are fitted and introduced into the MHD calculation model. The gas backflow phenomenon under the influence of multi-component gas and arc is further simulated. The results show that the muzzle arc improves the energy level of the muzzle flow field and promotes the gas backflow to a certain extent.
Study on the operation mode of repetitive inductive pulsed power supply
Authors: Chen Y , Li H T , An Y Zh , Hu Y Ch , Jiao C , Liang X Y 
Published: July 2020

Abstract
Inductive hybrid pulsed power supplies (PPS) have attracted widespread attention in the field of electromagnetic Launch (EML). In our previous studies, a repetitive inductive PPS circuit topology based on a bridge-type capacitor switching circuit and a high-temperature superconducting pulsed power transformer(HTSPPT) was proposed. By using superconducting inductors, this circuit reduces the power requirements of the primary power supply. However, to prevent the charging current from exceeding the critical current of the superconducting inductors, the circuit must enter the discharging phase immediately when the charging current reaches the designated value, even the discharge time is inappropriate. On the issue, this paper proposes a new operation mode, which is inspired by the trickle charging of accumulators. In this mode, the circuit can keep working in the introduced trickle charging phase until the discharge pulse is required. To study the feasibility of this mode, a preliminary experiment was carried out based on an HTSPPT. The results show that the discharge time can be controlled by instructions and the proposed operation mode is feasible. In addition, the critical parameters and error control methods of the proposed operation mode are also analysed and discussed.
Analysis and optimization of the two-dimensional model of the armature rotation on the electromagnetic railgun
Authors: Liu Xiangrong , Ma Fuqiang , Wei Jiufu , Li Baoming 
Published: July 2020

Abstract
In order to generate enough electromagnetic torque on the armature during the electromagnetic launching process, an asymmetrical structure is adopted in this paper. And a two-dimensional armature model is established for analyzing this asymmetrical structure. Based on this model and the translational equation of the armature, the size parameters of the armature are optimized under the premise of the fixed device parameters of the pulse power supplies and the barrel. The effective length of the armature is between 5mm and 20mm, and the radius of the internal contour for the armature is between 0 and 4mm. The results show that when the above two parameters are 20mm and 4mm respectively, the armature can obtain the largest angular velocity. The maximum value is up to 1087.3rad/s. It is meaningful to guide the armature design of the electromagnetic railgun.
Research on intelligent decision of fire distribution in remote control weapon station
Authors: Wu Y C , Zhang Zh Y , Xiang X F 
Published: July 2020

Abstract
The complex and changeable battlefield environment and personal emotions may affect the decision-making of the battlefield. In order to reduce these effects, make the remote weapon station autonomous, fast, reasonable distribution of firepower, to achieve accurate and effective target strike. In this paper, according to the difference of attacking targets, the threat evaluation models of different targets are established, the evaluation functions of target attributes are set up, and the ranking results are compared with the commander’s subjective decision-making. The evaluation results of the model are consistent with the expert evaluation results. It is proved that the remote control weapon station can overcome the subjective factors and strike the target reasonably when it distributes fire to different attacking targets according to the model, which has high reliability.
Application research on fiber-optic current sensor in large pulse current measurement
Authors: Ye W , Dong Z , Ren R , Liu J , Huang K , Zhang C 
Published: July 2020

Abstract
Rogowski coil is usually used to measure pulse current in directed energy weapon experiments, which is lack of direct and low-frequency components in current measurement, and influenced by interferences like outside electromagnetic field and mechanical vibration. To acquire pulse current data with higher accuracy, a new kind fiber-optic current sensor is proposed to achieve large pulse current measurement, and working principle of the sensor is introduced in this paper. A fiber-optic current sensor is fabricated by cooperative agency, which has measuring range from 0 to 200kA and precision better than 1%. Comparison experiment between the fiber-optic current sensor and Rogowski coil made by PEM from England is tested. The experiment results show that main components of pulse current waves measured by two sensors are similar. Current wave measured by fiber-optic current sensor gets less noise signal than Rogowski coil, and has more details with small current. The fiber-optic current sensor could achieve direct and low-frequency component current measurement, but its max response frequency is 500 kHz. According to the research results, compared to Rogowski coil in pulse current measurement application, the new kind fiber-optic current sensor has better character in direct and low-frequency component current measurement, strong anti-interference ability, high sensitivity and ability to acquire current measurement data with higher accuracy. This sensor would satisfy measurement demands of large pulse current measurement in directed energy weapon better, if it gets better frequency response ability.
Comparative study on longitudinal momentum characteristics of L-type and I-type breech in railgun
Authors: Xu Y T , Li B M 
Published: July 2020

Abstract
The position and magnitude of the longitudinal force during launch are very important to the design of electromagnetic railgun. This problem has become a hot topic of research for a long time. Previous experiments showed that most of the recoil force of the electromagnetic railgun locates at the breech. In order to study the stress distribution and momentum characteristics of the breech during launch. Based on Maxwell’s stress tensor, the momentum conservation equations for electromagnetic railgun were derived. Depending on whether the direction of the source current is perpendicular to the current direction in the rails, the breech is simplified and summarized into I-type and L-type structures. Then, the 3-d models of the two breeches were established and the launch process was simulated by finite element method. Some results such as the current density, magnetic field intensity and electromagnetic stress of the current injector plates and coaxial power connector under both models were obtained. The simulation results show that the longitudinal force on the breech is concentrated on the current injector plates. The longitudinal force on the power connector of L-type breech is much bigger than that of the I-type breech, up to nine times. Besides, different structures of the breech will not affect the launch performance of the railgun.
Research on Anti-seated Device of Certain Electromagnetic Weapon
Authors: Fan T F , Ma J J , Huang K , Huang Q 
Published: July 2020

Abstract
The electromagnetic railgun is a new concept weapon that uses Loren magnetic to accelerate the projectile to super high-sonic speed instantaneously. The initial velocity of the projectile muzzle can reach 2km/s or more in an instant. The projectile launched by the electromagnetic railgun has a high speed and thus has a strong kinetic energy to impact the target. According to the principle of force, when the weapon system pushes the armature, the recoil part will be subjected to a force in the opposite direction, that is, the combined force of the gun. If there is no anti-rear device, the force will generate strong vibration excitation to the launching frame, affecting the shooting intensity of the projectile. In order to reduce the influence of the squat resistance of the electromagnetic weapon on the accuracy of the weapon system, the model of the anti-rear device of the electromagnetic weapon is established. The simulation analysis and experimental verification are carried out. The simulation structure and experimental data are in good agreement.
Feasibility analysis and simulation study of shooting after shortest distance between target and projectiles
Authors: Chang S F , Wang J , Li X J , Fan. Ch X 
Published: July 2020

Abstract
In order to make full use of the performance of high-muzzle-velocity anti-aircraft weapon, make full use of the target firing segments on the entire route of the target, fully grasp all the firing opportunities, and reduce the possibility of a target breaking through the defense, the original pre-navigation firing (firing before shortest distance between target and anti-aircraft gun) method based on a muzzle velocity below 3ma cannot meet the needs mentioned above. Based on the establishment of high-muzzle velocity projectiles, this paper aims at the current situation of less post-navigation firing (firing after shortest distance between target and anti-aircraft gun), verifies the feasibility of post-navigation firings by analyzing the relative remained velocity required to penetrate the target, and verifies that with the gradual increase in projectile muzzle velocity, its firing range and timing can increase simultaneously. It provides a theoretical basis for post-navigation firing, increases the firing opportunities for the target on the entire route, and provides a reference for the demonstration, design and testing of the new anti-aircraft fire control system.
Impact envelope simulation for kinetic kill missile intercepting short range high speed target
Authors: Chen Kun , Ren Yang , Gong Zheng , Lu Qi 
Published: July 2020

Abstract
For direct impact kinetic kill missile, it not only need high precision guidance technology, but also related to the size, collision position, angle and speed of missile and target. Due to the limitations of the real projectile interception test technology, the cost and the launching technology of ground hypervelocity collision experiment, the simulation modeling and analysis are the main means to carry out the research of direct collision kinetic technology and the evaluation of interception effect. In this paper, aiming at the kinetic energy interception of short range high-speed target under the constraints of collision angle and miss distance, the terminal impact envelope is simulated, and the relative position of missile and target on the collision probability is analyzed.
Reynolds number effects of supercritical airfoil with mini-TED in transonic flow
Authors: Xu X , Liu D W , Chen D H , Cheng K M 
Published: July 2020

Abstract
In order to accurately investigate the Reynolds number influence of supercritical airfoil with miniature trailing-edge devices (mini-TED) under transonic conditions. The supercritical airfoil pressure measurement test of high Reynolds number was conducted in the European transonic wind tunnel. The reliability of the high Reynolds number numerical calculation method was validated by the wind tunnel test results. The calculation results are in good agreement with the wind tunnel test results, indicating that the high Reynolds number calculation accuracy could meets the investigation requirement. The transonic flow of supercritical airfoil with mini-TED in the range of Reynolds number 3×106∼50×106 and Mach number 0.76 was simulated using the validated calculation method. Due to the existence of mini-TED, the Reynolds number influence self-adjustment range of the supercritical airfoil disappeared, while the influence magnitude and sensitivity reduced. At the same time, the supercritical airfoil’s linear influence of Reynolds number effects has been changed, and the Reynolds number prediction method based on pressure distribution is no longer applicable. After considering the influence of Reynolds number, the detailed design of supercritical wing with mini-TED could be conducted to improve its reliability and economy in the application of advanced aircraft.
Finite element analysis of the friction and wear of the barrel bore during the projectile extrusion
Authors: Zou L B , Yu C G , Feng G B , Zhong J L , Liu X F , Liang L 
Published: July 2020

Abstract
The size change of the forcing cone directly affects the ballistic performance of the gun and the life of the gun barrel. In order to study the force law and wear law of the forcing cone during the continuous engraving process of the projectile, which established a refined finite element model of the projectile-barrel interaction. The model contains rifling finite element mesh grid with process chamfer. Based on the established transient coupled thermo-mechanical finite element (FE) model of the projectile-barrel interaction, the effects of the temperature and pressure of the gunpowder gas, the friction coefficient between the rotating band and the forcing cone were comprehensively considered. Combined with the Archard wear model, numerical method are used to obtain the stress law of the forcing cone and the amount of wear due to friction in the continuous engraving process of the projectile. The research content in this article can provide some guidance for predicting the life of the tube.
A simulation method of active protection system defeat probability
Authors: Yang Y , Song H P , Wang P G , Zhang Y N 
Published: July 2020

Abstract
The past thirty years have seen increasingly rapid advances in the field of Active Protection (AP) technics, and it is widely accepted that the AP system will play a marked role in future combat vehicle design, on account of its contribution to increasing vehicles’ viability without the burden of heavy armor. Depends on their concepts, a conventional AP system may consist of various components range from detectors, sensors, controllers, launchers to countermeasures, and what stands out in the AP system design are the inevitable errors derived from each operating session making the engagement results unpredictable, for example the tracking error of sensors, position error of launcher deployment, etc. The modelling method presented in this paper is a useful account of how to evaluate the AP system errors, and estimate the defeat probability of AP system upon the given boundary conditions.
Modeling of structure formation of energy-saturated heterogeneous composite material
Authors: Kryvanos A.K. , Ilyushchanka A.Ph. , Buloychik V.M. 
Published: July 2020

Abstract
One of the approaches to modeling of the structure formation of an energy-saturated heterogeneous composite material (EHCM) by mixing its components represented by liquid and solid phases was considered. To develop a model of the mixing process, one of the heuristic algorithms was used, i.e. the metal annealing method. The model is formalized with the condition of averaging the particle sizes within each of the fractions, as well as the morphology of their surface. As a representative element of the model, an elementary cell is adopted in the form of hexogonally densely packed particles around one introduced into the composition of the composite material (in small amounts, from 5 to 15 %) as a modifier. The voids in the cell are filled with liquid polymer. The developed model is based on the objective function, which assumes obtaining a uniform distribution of components with the required density of their packing and filling the voids with a liquid phase while minimizing the number of mixing iterations. A comparison of the values resulted during modeling with the measured characteristics of mixing on a particular mixer will make it possible to form a matching scale of the modeling results to the operating modes of technological equipment. This will determine the appropriate modes of mixing the components at the stage of development of the technological process of EHCM production.
Quantitative analysis for affecting factors of firing dispersion of tank
Authors: Liu F F , Song M , J Z  , Yu H L , Si Z H , Xu Y F , Cheng Y G , Ding M K , Rui X T 
Published: July 2020

Abstract
To improve the firing dispersion of the tank, the influences of random factors on firing dispersion are analyzed quantitatively. Based on the six-degree-of-freedom rigid-body ballistic equation, considering the influences of processing and assembly errors, initial disturbances and the wind on flight, using the Sobol’ global sensitivity analysis method, the weights of affecting factor are obtained. The analysis results show that, under the current manufacturing and measuring conditions, the initial disturbance of projectile is the premier factor that takes effect on the firing dispersion of the straight shooting weapon (such as a tank) with small elevation angle.
Study of coupling thermal and mechanical effect on submerged nozzle in solid rocket motor
Authors: Gong J L , Xue R , Deng Z 
Published: July 2020

Abstract
The thermo-structural response of submerged nozzles is widely investigated in the design of modern rockets upon thermal loading and aerodynamic pressure. In this paper, by means of commercial finite element software with the subroutine of non-uniform pressure and non-uniform heat transfer coefficients, the simulation was performed to study the thermo-structural response of a submerged nozzle at the pressure 6MPa and stagnation temperature 3200K. By means of fluid software, the steady flow field with hot gas was determined. The aerodynamic parameters and heat coefficients were obtained. It was found that the thermal loading has an important influence on stress of throat insert for the solid rocket motor (SRM). Secondly, the hoop stress increases at first and then decreases with the increase of time for the throat insert. Finally, the ground hot firing test of SRM with submerged nozzle was carried out. The structural integrity of the submerged nozzle is very perfect during SRM operation. The present method is reasonable, which can be applied to study the thermo-structural response of submerged nozzle for SRM.