bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study on fuze-guidance integration technology for improving air target striking capability of fortification storming/heat missiles
Authors: Zhao J M , Hu G H , Li X G , He J , Chen Y , Chen S Ch 
Published: July 2020

Abstract
In order to realize air-ground integration strike capability of the fortification storming/HEAT missiles, with the study background of addition of a laser proximity fuze to the missile, this paper proposes a fuze-guidance integration design method based on combination of image guidance and laser proximity fuze detection. By utilizing the missile-target encounter images, the gimbal angle of the seeker, the velocity and attitude of the missile, as well as the bearing and distance of the target detected by the laser proximity fuze, our design method establishes the space geometric equations of the relative motion of the missile and target, and of the equivalent conical plane of the dispersion center of the warhead fragments in the coordinate system of the missile body. Meanwhile, by solving the equations, a fully formulaic optimal time delay model of fuze-warhead matching is obtained, and the optimal detonation time of the warhead is given. The results show that this integration design method can effectively improve the damage effect of the missile on the helicopter target under complex encountering conditions, and realize the integrated air-to-ground strike capability of the fortification storming/HEAT missile.
Experimental study on knocking combustion in compressionignition engines under high-altitude conditions
Authors: Li H Y , Zhang X Q , Qiang Y P , Zhu W Q , Li Y Z , Li Y F 
Published: July 2020

Abstract
Diesel engine combustion becomes very rough or even detonation under high altitude conditions, which is harmful to components durability. In this study, combustion characteristics were experimentally investigated on a V6 heavy-duty diesel engine using by a plateau simulation test bench to simulate altitude conditions of 1000 m, 3000 m and 4500 m. Results show that extremely high peak pressure rise rates of above 50bar/°CA exist at low speeds under the altitude of 4500 m. This indicates that not only does knocking combustion exist in spark-ignition (SI) engines, but also can be found in compression-ignition (CI) engines. Knock intensity (KI) is calculated by the pressure oscillation with high-pass filtering (HPF). Approach of cycle to cycle variation was adopted to study combustion characteristics on the comparisons of knock and non-knock states. Also, the correlation between KI and peak pressure rise rate was revealed through the linear regression method.
Dynamic fracture of the AISI 1045 steel cylinders under internal blast loading
Authors: Ma Y , He Y , Wang CT , He Y , Guo Z P , Hu X B 
Published: July 2020

Abstract
Dynamic fracture failure of the AISI 1045 steel cylinders with variable depth grooves under internal blast loading was investigated. Lateral and longitudinal grooves were curved on the wall of steel cylinders along with radial direction. All grooves have a V-shape with 20° angle. After blast, the morphology of fragments recovered by multi-layer wooden plank showed relative consistency. Microstructure in cross and longitudinal section of the fragments was examined by scanning electron microscope (SEM). The microstructure observation suggested that there were some undeveloped shear bands and the dynamic fracture modes were similar in the all tests but the different fracture mode in two directions. Relevant numerical simulation by LS-DYNA were carried out to analyze the expanding and fracture process of cylinders under internal blast loading. Numerical results have acceptable agreement with experiment results. The mass loss rate of shell after explosion is negatively correlated with the depth of grooves.
Structure of copper shaped charge liner evolution law based on die forging process
Authors: Zhang M Y , Gao P , Yan Z F , Tian T , Cai W Z , Jia X B 
Published: July 2020

Abstract
Numerous studies have addressed the effect of grain size of materials on the overall penetrating performance of warheads. However, the use of the forging process to illustrate the grain heat-treatment refining technology has not been reported. In this experiment, the grain size of copper was observed and evaluated during the main processes of preparing copper shaped charge liners using the die forging process. Through this study, the evolution law for the structure of copper shaped charge liners was examined. In the as-cast condition, the grains of the copper ingots were mostly evenly distributed large flaky equiaxed crystal. Pre-forging and die forging make the grains appear more like strips. After the recrystallization heat treatment, the grain size of the copper shaped charge liner was refined and more uniform. Using these results, this study presents an evolution curve for copper shaped charge liners prepared using the forging process. The results can be used as a technical reference to solve the problem of grain size deviation in the production process of copper shaped charge liners.
Analysis characteristics and causes of adiabatic shear bands produced during the artillery barrel explosion
Authors: Zhang Zh W , Wang F , Liu S F , Li Zh J , Sun Y D , Zhang Y 
Published: July 2020

Abstract
It was studied that the characteristics and causes of adiabatic shear bands produced during the artillery barrel explosion when launching medium caliber projectiles. It shows that at the breech position, the strain required for the adiabatic shear band can be achieved, resulting in the adiabatic shear band, which is in a state of discontinuity and has an angle of about 20∼45 degrees with the barrel. After the appearance of adiabatic shear band, the strain rate is very high, and high heat is produced locally due to large plastic distortion, which can not be output, resulting in the intensification of deformation and the bursting of barrel. And the same time, the critical shear strain and temperature of the adiabatic shear band are calculated under this condition.
Study on mechanical properties and fragmentation under detonation loading of different types of tungsten alloys
Authors: Tang J J , Liang Zh F , Qu K P 
Published: July 2020

Abstract
In practical engineering, the fragments of warhead may be deformed and broken due to strong extrusion, material softening and other factors, which seriously affects the damage strength of warhead. In this paper, 93W-Ni-Fe, which is commonly used as fragment material, was selected as the research object. The static and dynamic properties of 93W fragments obtained by two different heat treatment processes were tested, and the crushing property and dynamic stress-strain curve were obtained. The static explosion test was also carried out. After the fragments were recovered, it was found that 1# fragment can basically ensure the integrity, 2# fragment had more fragmentations. The study showed that the fragmentation of tungsten alloy fragments was closely related to its structural characteristics and dynamic properties. The low stress and large deformation characteristics of 2# fragile specimen may be related to the distribution of the bonding phase.
Simulation and experimental study on the shock response of vehicle add-on modules subjected to blast loading
Authors: Wang J , Jiao L J , Li J S , Li N , Tao Z G , Song C M 
Published: July 2020

Abstract
Explosion of landmines is recognized as one of the vital threat to armoured vehicles. The detonation of mines may also threaten the survivability of the occupants inside the vehicle by the high intensive blast waves transmitting from vehicle structures. Bottom add-on modules can be very useful to vehicle in blast protecting. The dynamic response of three different add-on structures under bottom explosion was analysed by simulations and experiments. The optimal structure was obtained by computational results and experimental results, and the protection mechanism was summarized based on the research.
Shock wave compressibility of composite materials based on aramid fibers
Authors: Mochalova V M , Utkin A V 
Published: July 2020

Abstract
Using a VISAR laser interferometer, the experiments on investigation of the shock wave structure, spall strength and determination of Hugoniot parameters were performed for two composite materials based on the aramid fibers. Textolite and Kevlar were made using the same epoxy resin and aramid fibers, but had a different structure - unidirectional fibers and plies of woven fibers, respectively. The density of these materials is approximately 1.27 g/cm3. To study the shock wave compressibility of composite materials under high pressure, the explosive propellant charges were used to provide a flat throw of aluminum flyer plates with velocities from 0.7 to 5.05 km/s. As a result of experiments, particle velocity profiles on the composite/water boundary were obtained. On the velocity profiles for kevlar and textolite with transverse orientation of the fibers, after the initial shock jump, oscillations are observed due to the heterogeneous structure of the investigated materials. Unlike the composite materials with transverse orientation of the fibers, in the case when a shock wave propagates along the fibers, a two-wave configuration is recorded, which is due to the anisotropic structure of material. It was found that Hugoniots of composites with perpendicular orientation of the fibers are parallel to each other and differ only in the first coefficient determined by the sound speed of the material. Also a study of spall strength of textolite and Kevlar was performed. It was found for both materials that the value of spall strength along the fibers is higher than that for the transverse direction.
Fabrication and dynamic compressive response of reaction sintering H-BN ceramic
Authors: Gao X J , Sun M Y , Huang W P , Zhang M Y , Wu Y Ch , Zhang W , Wang Ch 
Published: July 2020

AbstractHexagonal boron nitride ceramic (h-BN) based on the nitridation of B powders was obtained by reaction sintering method. The dynamic compressive response was investigated using a Split Hopkinson pressure bar tester at high strain rates in a range of 0.8×103−1.6×103s−1. By increasing the strain rate, the dynamic strength and the failure strain increased continuously. The compressive stress–strain curves exhibited universal three deformation regions, including inelastic deformation region, rapid loading region and failure region. The failure mode of the h-BN ceramic depended upon the strain rate.
Simulation study on the influence of liquid level on anti-jet penetration ability of single-cell composite structure
Authors: Cai Y E , Huang Z X , Shen X J , Zu X D , Jia X , Ji Q 
Published: July 2020

Abstract
The liquid composite armour produces transverse interference to the sharped charge jet through the backflow of liquid in the inner cavity, which affects the subsequent penetration ability of the jet. Within this article, a single-cell structure filled with water is take as the research target. Through numerical simulation, the process of shaped charge jet penetrating the single-cell structure at different liquid level is reproducing, and the parameters of the remaining jet after penetration, the interference of jet, and the deformation and energy absorption of shell are obtained. The results showed that the liquid level of liquid-filled single-cell structure has a significant influence on the anti-jet penetration ability of the single cell structure. When the liquid level was 60mm to 65mm, the water-filled single-cell structure has the best interference effect on the incoming shaped charge jet.
Performance test and application of the large diameter multi-point ring initiator for a shaped charge
Authors: Yu Rui , Wang Ping , Zhang Xin Ming 
Published: July 2020

Abstract
A series of experiments were conducted to investigate the synchronicity of the large diameter multi-point ring initiator applied to a shape charge(SC). With the multi-point ring initiator applied to SC, the penetration capability of the SC to penetrate in the reinforced concrete targets were studied. The output Synchronicity of all points of the multi-point ring initiator with diameter of 366mm was measured by the DL-32.II time interval tester. It shows that the output synchronicity of all points is good and the maximum time difference is less than 105ns. The SCs with two different initiation diameters were initiated to penetrate into the reinforced concrete targets. Experimental results show that the dimension of crater and inlet increase with initiation diameter of SCs.
Optimization design for countersink depth error prediction and compensation of CFRP/Al stacks
Authors: Zhang Yuxi , Wu Dan 
Published: July 2020

Abstract
The countersink depth accuracy is one of the most important quality indexes of the rivet holes in modern aerospace industry, especially in the drilling of thin-walled carbon fiber reinforced plastic (CFRP) and aluminum (Al) stack. However, the carbon fiber of CFRP is a kind of typical difficult-to-machine material, which results in the terrible wear of the cutting tool, and then the continuously increase of thrust force in the practical machining process, leading to the significant stack deformation and making it difficult to achieve the required countersink depth tolerance. Focusing on the countersink depth control in the drilling of the thin-walled CFRP/Al stack, this paper attempts to optimize the integrated methodology [10] in order to predict and compensate for the stack deformations more accurately. In this paper, an analytical flexible countersinking thrust force model that considers both tool wear and stack deformation is first developed with detailed theoretical analysis. Then a finite element model is established to identify the key features of the stack deformation in the countersinking process. An optimized iterative algorithm, which consists of three nested iterative loops, is designed to calculate the feasible stack deformation and make decision for the error compensation. Finally the optimized methodology are verified by groups of cutting experiments, and the results have shown that the methodology could effectively guarantee the countersink depth accuracy. The work in this paper enables us to understand the generating mechanisms of the countersink depth error in the drilling of the thin-walled CFRP/Al stack, and provides a novel approach to improve the countersink depth accuracy.
Study on reaction productions and morphology of Al-Ti-C-SiC master alloy in self-propagating high temperature synthesis
Authors: Zhang Guowei , Niu Jingwei , Xu Hong 
Published: July 2020

Abstract
Al-Ti-C-SiC master alloys were prepared by self-propagating high-temperature synthesis method with the aluminum powder, titanium powder, graphite powder and nano-SiC powder. The reaction productions and morphology of Al-Ti-C-SiC master alloy were systematically investigated. The results show that with the addition of SiC nano-particles, the reaction sequence of self-propagation synthesis of Al-Ti-C alloy was changed. During the reaction, the SiC nano-particles reacts with the titanium powder, which leads to an increase amounts of the TiC particles, In the self-propagation products of Al-Ti-C-SiC system, the size of TiC particles decreases first and then increases with the increase of SiC nano-particles mass fraction. When the mass fraction of SiC nano-particles is 10%, the size of TiC particles becomes nanometre, which size reach 100nm-200nm. When the mass fraction of SiC nano-particles is more than 10%, SiC nano-particles can be found in the master alloy product.
Stiffness-similar models for wind tunnel tests based on 3D printing
Authors: Zhu W , Zuo Z , Li D , Tian X , Luo M , Shang J , Li D , Ding X , Sun Y , Zhang Z , Zhang B , Zhang Z 
Published: July 2020

Abstract
Wind tunnel testing is a reliable means for R&D aerial vehicles of aerospace, e.g. aircraft, missiles, rockets etc. The wind tunnel models are the objects used in the tests, and stiffness-similar models are important for the structural and aerodynamic design of aerospace vehicles. The accuracy and economy of the model design and fabrication have a significant impact on the quality and cycle of vehicle R&D. The review will first give an overview introduction of the wind tunnel models with stiffness-similarity, and then detail design procedure and fabrication processing, which are developed by the author’s group based on 3D printing. The review can provide new methods to design and fabricate stiffness-similar models for wind tunnel tests for designers and researchers concerning the structural and aerodynamic studies in the aerospace industry.
An initiator integrated the AI/MoO3 multilayer nanothermite and bridge-wire electrode plug
Authors: Ni D B , Dang P Y , Yu G Q , Chu E Y 
Published: July 2020

Abstract
Lead styphnate is a primary explosive with low brisance, and is extensively applied into civil and military devices. Whereas the electrostatic sensitivity of LTNR is extremely high, it is disadvantageous for the safety of ignition system. In this paper, a novel initiator was integrated with Al/MoO3 multilayer film and bridge wire by magnetron sputtering. The thickness of Al/MoO3 multilayer was 3um with period of 20nm/30nm. The heat release of Al/MoO3 multilayer film was and 1164J/g, which was characterized by differential scanning calorimetry (DSC). And the combustion speed of film was about 5.3 m/s, it was characterized by high speed cameral and laser ignition system. The firing sensitivities was measured by Langly method, the 50% and 99.9% firing-current sensitivity of initiator was 0.08A and 0.11A, respectively, and the 50% and 99.9% firing-voltage sensitivity of initiator was 2.30V and 2.56V, respectively. The firing sensitivities of Al/MoO3 multilayer film was almost equal to the LTNR. The insensitive ignition composition of B-KNO3 tablet was easily fired with in the gap of 2.12 mm. And the initiator can easily fire the lead azide in detonator. All of these, it is suggested that Al/MoO3 multilayer film will expect to be a substitute for LTNR and improve the ignition ability and safety of ignition system and has a significant influence on the design of explosive devices.
Real-time localization, mapping and navigation for quadruped robots
Authors: Pan Y Y , Ding X Q , Yang T , Wang Y , Xiong R , Jiang L 
Published: July 2020

Abstract
Autonomous quadruped robots require localization and mapping for navigation. Different from mobile robots, quadruped robots need local dense maps with more detailed information for motion planning. A key challenge, limited by the capacity of computers on robots, the perception systems have to balance the properties of the speed and accuracy to ensure that robots reach their destinations quickly and safely. In this paper, we propose a complete solution for the autonomous movement of quadruped robots. Localization is achieved by the Extended Kalman Filter which is updated by the results from laser based the ICP algorithm. Dense maps are created by raw ranger sensor data and accumulated base on accurate localization results. And then, dense maps are transformed to the occupancy grid maps which contain free and occupied space information for planning. For implementations, we demonstrate the effectiveness of our approach in a complex outdoor environment.
Full attitude tracking control of a tiltrotor UAV on SO(3)
Authors: Dong Shimeng , Zhang Tao 
Published: July 2020

Abstract
This paper presents novel results for the attitude tracking control of a tiltrotor unmanned aerial vehicle (UAV). This kind of UAV has two tiltable rotors while both thrust force and thrust direction can be controlled, and thus has four input degrees of freedom. A nonlinear dynamic model defined on SO(3) is proposed and analysed. An attitude tracking controller is developed using Lie Group and Lie Algebra theory, achieving smooth attitude tracking and avoiding the singularity problem of Euler Angles. Numerical simulation shows the controller has desirable closed loop performance and global asymptotic stability.
Bionic design and anti-slip characteristics study of quadruped robot foot
Authors: Tian W J , Xu Y J , Xu W , Xu P , Zhang Q , Cong Q 
Published: July 2020

Abstract
Quadruped robot has been widely used in the field of national defense because of its high adaptability. The stability and balance capacity is the important performances needed during the quadruped robot moving under uneven terrains, and the slip resistance of the foot affects the balance performance of robot. As the goat hoof with irregular surface morphology adapts to rugged terrain, its plantar geometric shape was reconstructed using reverse engineering technology based on the point clouds which were obtained by using a 3D hand laser scanner. The bionic foot was designed based on goat hoof plantar surface, and the anti-slip characteristics were analyzed by finite element method, and then compared with the spherical foot and cylindrical foot. The frictions between these feet and soils or rocks at different pressures were investigated, and the result shows that the maximum static frictions between bionic and soil and rock are greater than that of the two others, which means bionic foot has better anti-slip performance.
Slam algorithm for aruco landmark array based on synchronization optimization
Authors: Xing B Y , Dang R N , Xu P , Jiang C X , Jiang L 
Published: July 2020

Abstract
High precision mapping algorithm is the core of two-dimensional(2D) landmark array(the ArUco landmark is used in this paper) localization application. In most of the existing mapping algorithms, the accumulated errors of online methods can not be eliminated, meanwhile, the manual calibration and off-line methods are inefficient and time-consuming. In order to overcome those shortcomings, a real-time simultaneous localization and mapping(SLAM) algorithm for landmark array based on synchronized optimization is proposed in this paper. The proposed algorithm updates and corrects the global map online, and the accumulated errors is optimized based on minimizing the re-projection error of the landmarks ’ vertexes. In order to verify the proposed algorithm, several contrast experiments with other mapping systems are presented. The experimental results show that the proposed algorithm has the advantages of high map precision and small accumulative error.
Research on multi-address autonomous access technology of uav cluster data link based on priority statistics
Authors: ZHang J L , Wa F , Hao Q 
Published: July 2020

Abstract
As a uav cluster that can change the future combat situation, its data link has the requirements of high speed, low delay, dynamic networking and large network capacity. In this paper, a priority statistics based multi-address autonomous access technology for uav cluster data link is studied. Firstly, the channel load is detected and predicted by time-frequency analysis for different priority services. Then, multi-node information fusion is adopted for multi-address decision-making. Finally, the designed technology is simulated by Qualnet software. The simulation results show that the proposed multi-address autonomous access technology based on priority statistics can effectively reduce in-network channel collisions and realize low-delay transmission of high-priority services.