Table of Content

28 February 2014, Volume 35 Issue 2

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Paper

A Lumped-parameter Model of Battery Pack Heat Transfer in Electric Vehicles

WANG Fa-cheng, WANG Zi-dong, HU Dao-zhong, TONG Yu-qi, GAO Hong-bo, CHEN Fen

2014, 35(2):  145-151.  doi:10.3969/j.issn.1000-1093.2014.02.001

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With the booming development of the modern vehicle industry, the safety problem caused by heat generation of battery pack is more and more obvious, an effective heat transfer system needs to be developed. Based on analyzing the average heat generation rate of a battery pack, a heat transfer simplified model of battery pack is established using a lumped-parameter method. This model is used to analyze the following parameters of an actual battery pack: time interval, fluid temperature, battery pack average temperature, transient heat transfer power, and total heat. The calculated results can be used to evaluate whether the heat transfer system is effective, or make the heat transfer system reasonable by choosing the optimum heat transfer parameters. The results also indicate that the strategy of applying fluid with constant temperature in the heat transfer system is not the best.

Guaranteed Cost Optimization for the Shell Transfer Arm with Interval Uncertainty

SHI Hai-jun, QIAN Lin-fang, LI Miao

2014, 35(2):  152-157.  doi:10.3969/j.issn.1000-1093.2014.02.002

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A guaranteed cost optimization method based on analysis of parameter interval uncertainties is proposed to overcome the disadvantage in design optimization of shell transfer arm. In this proposed method, the interval characteristic of key dimensions or material parameters in the engineering design is considered, and the parameter perturbations are mapped from variation space into objective and constraint spaces, then the obtained degraded-estimation of objective and constraint is acted as an additional constraint of original optimization problem, resulting in a new robust optimization of an outer-inner optimization structure. The optimization results of shell transfer arm show that the proposed method is effective in solving complex engineering optimization problems with interval uncertainties.

Analysis on Firing Rate Characteristics of Duplicate-aim Artillery

WANG Xiang-min₁, YAO Xing-tai₂, WANG Jun₁, GUO Zhi₁

2014, 35(2):  158-163.  doi:10.3969/j.issn.1000-1093.2014.02.003

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Under the assumption that the firing data error is a normal stochastic process of mean square differentiability and ergodicity, the distribution characteristics of stochastic passage period when firing data error passes through the elliptic shot area is given for the duplicate-aim artillery. While the preparing (recoil, counter-recoil, filling and aiming) time of artillery is taken into consideration, the distribution characteristics of random firing rate is deduced, and then the analytic expression for average firing rate is given.

Surface Pressure model of Rifle Bullets Penetrating into Ballistic Gelatin

MO Gen-lin, WU Zhi-lin, FENG Jie, LIU Kun

2014, 35(2):  164-169.  doi:10.3969/j.issn.1000-1093.2014.02.004

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A surface pressure model is presented to study the translational and tumbling motions of rifle bullets penetrating into ballistic gelatin. In the model, it is assumed that each area element is under the action of normal dynamic pressure and material resistance. The resultant force and moment on a projectile are obtained through numerical integration of surface pressure. The trace of a projectile is calculated by solving spatial motion equations deduced from the mass center motion equations and Euler equations of motion with Runge-Kutta method when the initial conditions are given. A 7.62 caliber bullet is tested to verify the surface pressure model. The agreements between the theoretical results and experimental data including displacements and projection angles show that the model is applicable in predicting the translational and tumbling motions of rifle bullets.

Numerical Simulation and Experimental Study on Explosion-proof Structure Design of Tandem Shaped Charge

XU Hao-ming, GU Wen-bin, LIU Jian-qing, ZHAO Chang-xiao, XU Wei-you, HU Ya-feng

2014, 35(2):  170-175.  doi:10.3969/j.issn.1000-1093.2014.02.005

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In order to solve the optimal matching issue of penetrating hole depth and aperture on fast perforating into a hunk obstacle, a new tandem shaped charge structure is proposed, which uses two same structures of explosively formed projectile (EFP) shaped charge. The effect of explosion-proof structure on the penetration ability of tandem EFP charge is analyzed by using finite element software, and the associated experiment of tandem EFP penetrating into a steel target is conducted. The results show that the shape of explosion-proof body has an important effect on the penetration ability of postpositive charge of tandem EFP, and the whole penetration depth of optimized tandem EFP and the penetration depth of postpositive charge are increased by 23% and 35%, respectively, greatly improving the efficiency of postpositive EFP charge.

Study on Coordination Technology of Guidance Integrated Fuze and Gimbaled Warhead

XU Jun-feng, JIANG Chun-lan, LI Ming

2014, 35(2):  176-181.  doi:10.3969/j.issn.1000-1093.2014.02.006

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The kill probability calculating models of one-missile to one-target for the gimbaled warhead, which is designed to fire the fragments in the target direction, are studied in order to optimize lethality. Two encounter concepts of side-attack and forward-intercept at endgame are formulated in the missile coordinate system. The kill probability is calculated using Monte-Carlo method. Based on the circular spray pattern with uniform pattern density, the optimum lethal radius is established for forward-intercept concept. And then the effects of missile-target relative velocity and miss distance on kill probability are analyzed. According to the study, the preferred conditions for side-attack or forward-intercept are proposed: if v_r≥1 700 m/s and ρ≤2.5 m or v_r≥3 000 m/s and ρ≤4 m，then the encounter concept of forward-intercept is preferable; In other cases, the encounter concept of side-attack is preferable.

A New Deterring Technique of Azidonitramine Propellant

HUANG Zhen-ya， FAN Jian-fang， CHEN Yu-qian

2014, 35(2):  182-187.  doi:10.3969/j.issn.1000-1093.2014.02.007

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To solve the surface-deterred problem of high-energy propellant with high plasticizer concentration, a small-molecule multiple alkynyl compound, such as Tripropargyl 1,3,5-benzenetricarboxylate(TPTM), is introduced as deterrent precursor. It could react with 1,5-diazido-3-nitrazapentane(DIANP) which is a ingredient of azidonitramine propellant to form high-molecule deterrent with cross-linked network structure after it is permeated into surface layer of azidonitramine propellant with spraying technique. The deterring effects are characterized by closed-bomb test and thermal-aging test. The results show that TPTM can reacts with DIANP at 50 ℃ completely. When the azidonitramine propellant is deterred with TPTM, the initial burning activity of the deterred propellant is substantially reduced, its progressive burning characteristic value L_m/L₀ reaches about 1.8 and B_m is about 0.5; and the combustion performance of the deterred propellant is ultimately unchanged after thermal-aging at 50 ℃ for six month. The small-molecule multiple alkynyl compound as deterrent precursor is applicable to the surface deterring of azidonitramine propellant, makes the deterring effect excellent and insures the long-storage stability.

Prediction of Shock Sensitivity of RDX-based Composite Explosive by Particle Swarm Neural Network in Large-scale Gap Test

YUAN Jun-ming, LIU Yu-cun, WANG Jian-hua, CHANG Shuang-jun, YU Yan-wu

2014, 35(2):  188-193.  doi:10.3969/j.issn.1000-1093.2014.02.008

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The large-scale gap thickness value of RDX-based composite explosive shock sensitivity is predicted by particle swarm neural network for reducing the number of tests and saving the test cost. 41 groups of RDX-based composite explosives with different densities, void ratios, charge structures and RDX contents are selected for test. The practical density of explosive, void ratio, RDX and additives content are taken into account as main influence factors. The nonlinear relationship among three influence factors and large scale gap thickness value is analyzed. The neural network model optimized by particle swarm algorithm is established for the above four variables and gap thickness value. The calculation results show that there is a good mapping model between the four variables and large scale gap thickness value; the predicted values are in good agreement with the experimental results, and the relative error is within 10%. The predicted value of the particle sarwm neural network can provide reference for the large-scale gap test of RDX-based composite explosive.

Combustion Performance of Boron Coated with AP

XIE Zhong-yuan, ZHOU Lin, WANG Hao, ZHAO Kai, LUO Yi-ming, ZHANG Hong-liang

2014, 35(2):  194-199.  doi:10.3969/j.issn.1000-1093.2014.02.009

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In order to study the combustion performance of boron (B) coated with AP, the AP/B composite particles are prepared by solvent evaporation method. SEM is used to observe the surface morphology of coating layers. The CO₂ laser ignition devices are selected to study its ignition and combustion characteristics. A calorimetric bomb is used to test the explosion heat of DNTF-based explosives with AP/B composite particles. Experiment results show that AP is homogeneously crystallized on the surface of boron and the fine coating layers can be obtained by strictly controlling the technical parameters and using the solvent evaporation method. In comparison with classical boron particles, the combustion characteristics of AP/B composite particles are significantly improved, and the light intensity is instantaneously approximated to its maximum value. The explosion heat (7 696 kJ/kg) of DNTF-based explosives with AP/B composite particles is 6.5 percent higher than that of uncoated explosive (7 208 kJ/kg), which indicates that the release energy can be effectively increased by coating technique.

Prediction Research on Cutting Surface Roughness of PBX Based on RBF Neural Network

TANG Xian-jin, ZHANG Qiu, ZOU Gang, WU Song, LIU Wei, YIN Rui

2014, 35(2):  200-206.  doi:10.3969/j.issn.1000-1093.2014.02.010

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The surface quality of polymer-bonded-explosive（PBX）is a key factor to influence the explosive components and the weapons. An avalanche phenomenon, which is created by material, process and operating condition, on the cutting surface of PBX is observed by analyzing the cutting surface 3D-contour of PBX, which causes the difference between 2D arithmetical mean deviation of the profile and 3D arithmetical mean deviation of the profile to be 32%. Hence, a prediction model which consideres the multiple factors is established with the RBF neural network. The training and test of the prediction model illustrates that the model could reflect the regularity of cutting process, and the predicted error is within 2%.

A New Chirp Signal Parameter Estimation Algorithm

CHEN Lei， CHEN Dian-ren， LIU Ying

2014, 35(2):  207-213.  doi:10.3969/j.issn.1000-1093.2014.02.011

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The output SNR at the true parameter values does not increase and the multiple peaks occur in WVHT image when the traditional Wigner-Ville-Hough transform (WVHT) is used to detect and estimate chirp radar signals. A chirp signal parameter estimation method based on period WVHT (PWVHT) is studied. The PWVHT formula of general signals is given, and the PWVHT formula of chirp signal is derived. The relationship among PWVHT output SNR, observation time and sample signal SNR is analyzed. The estimation error is analyzed and simulated using MATLAB. The results show that PWVHT is superior to WVHT for estimating a chirp signal that is composed of multiple pulses.

Research on the Influence Factors of Lightning-induced Over-voltage on Military Power Supply Cables

XIE Pu， ZHAO Jin-cheng， WANG Chuan-chuan， WANG Yong

2014, 35(2):  214-219.  doi:10.3969/j.issn.1000-1093.2014.02.012

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According to dipole model, the electromagnetic filed distribution laws at the discharge instantly time are acquired. A calculation model and a numerical solution of electric and magnetic fields of indirect lightning over-voltage are proprosed. The influence laws of lightning current amplitude, cable length, cable height, termination resistor and lightning location on induced over-voltage are discovered: peak value of indirect lightning over-voltage is proportional to lightning current amplitude, cable length and cable height. But when the cable length is increased to a certain size, the peak value of indirect lightning over-voltage increase rate tends to be small; when the starting end is the match resistance, the indirect lightning over-voltage of ending increases with the increase of end resistance. The lightning location in the vertical direction of the cable on distance increasing, the indirect lightning over-voltage rapidly decreases, and does not become direct ratio with the distance, which provides the quantitative indicators to the lightning protection design of the military power supply.

Research on the Guidance Law for Spiral Maneuver of Air-to-ship Missile in Dive Trajectory Phase

SONG Gui-bao, ZHU Ping-yun, LI Hong-liang

2014, 35(2):  220-227.  doi:10.3969/j.issn.1000-1093.2014.02.013

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For the penetration probability of air-to-ship missile adopting traditional flight trajectory is poor when it is intercepted by long-range ship-to-air missile, a scheme of modifying the descending phase trajectory to spiral maneuver dive trajectory is proposed. The design process of variable structure guidance law with terminal angular constraint is analyzed. On this basis, a kind of spiral maneuver variable structure guidance law is proposed. It can be used to guide the air-to-ship missile to realize the spiral maneuver dive trajectory, and ensure that the air-to-ship missile turns into the low altitude cruise phase in the end of the descending phase. The simulation results show that the proposed spiral maneuver variable structure guidance law improves remarkably the penetration probability of air-to-ship missile against the long-range ship-to-air missile.

Analysis of Vibration and Energy-absorption Characteristics of Sandwich Plates with Metallic Foam Cores andComposite Facesheets

HE Bo-ling, ZHAO Gui-ping, LU Tian-jian

2014, 35(2):  228-234.  doi:10.3969/j.issn.1000-1093.2014.02.014

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The metallic foam core of lightweight composite sandwich plates undergoes significant deformation along the thickness direction under shock loading, and hence the transverse normal and shear compressions of the core must be considered. A higher-order theory is used to analyze the transverse normal and shear strains of the core, whilst the Kirchhoff theory is used to analyze the thin composite facesheets because of their high-stiffness. The Hamilton's principle is used to obtain the equations governing the vibration performance of the sandwich plate. The extended Galerkin's method is used to solve the governing equations to obtain the vibration equation of the sandwich plate suitable for numerical analysis. The fourth-order Runge-Kutta method is employed to solve the transverse dynamic displacement of the sandwich plate within the elastic range. The inherent frequency of the sandwich plate is compared with the results of finite element method. Finally, the capacity to absorb energy of the sandwich plate is discussed by using the higher-order theory, and the influence of key system parameters is explored. The results show that the whole structural stiffness is affected by changing the ply angle of the facesheets and the thickness of the core, influencing the vibration characteristic of the sandwich composite; the structural vibration is weakened as energy is dissipated by the material damp; and the metal foam core absorbs most of the energy due to the transverse normal and shear compressions.

Dynamic Surface Sliding Mode Control for Large Hydraulic Erecting System

LI Liang, XIE Jian, HUANG Jian-zhao

2014, 35(2):  235-240.  doi:10.3969/j.issn.1000-1093.2014.02.015

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A nonlinear model for the large hydraulic erecting system is established by redefining the load flux and load pressure of the valve controlled asymmetrical cylinder. A dynamic surface sliding mode control method is proposed to overcome the nonlinearities and uncertainties existing in the erecting process of large erecting system, and the sliding mode control and dynamic surface control are introduced in designing this controller. The control law is presented. Simulation results show that, compared to PID control and conventional sliding mode control, the dynamic surface sliding mode controller has nicer robustness and tracking performance, and the control stability and robustness of erecting system are improved.

Optimization Design of Cartridge Pressing Structure for Feed Mechanism Based on the Sensitivity Analysis of Multi-attributeDecision Making

YANG Li， SUN Zhi-li， YIN Ming-ang， WANG Yu-ning

2014, 35(2):  241-247.  doi:10.3969/j.issn.1000-1093.2014.02.016

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Sensitivity analysis is an important optimization process of multi-attribute decision making, of which thorough analysis of attribute values or change of attribute weights makes great sense in making decision. On the basis of the linear weighting model, a sensitivity analysis method is proposed, the sensitivity problem which is caused by the change of an attribute value or more related attribute values and the change of an attribute weight or more related attribute weights is researched, and the critical value or the stable interval of sensitivity which keeps the original sort result of decision unchangeable are calculated by a quantitative calculation method. The example about some small-bore artillery feed mechanism shows that the method is scientific and feasible.

Long-range Penetration and Cooperative Search Decision-making of Multiple UAVs

GUO Hai-feng, DING Da-li, WU Wen-chao, LIU Yao-lin

2014, 35(2):  248-255.  doi:10.3969/j.issn.1000-1093.2014.02.017

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For the search problem of mobile targets in an uncertain region after long-range penetration, a long-range penetration and cooperative search path decision-making method of multiple UAVs is proposed. The basic planar diffusion model is improved, and an uncertainty region diffusion model is built by considering the target motion and the circumstance constraints. The strategy of the penetration decision and trajectory optimization search decision-making is researched for mobile target based on the algorithms of potential field and receding horizon control. The proceed function of the cooperative search is proposed in consideration that the uncertainty reduce proceeds, average uncertainty and integration cross, which is the trajectory optimization rule of the cooperative penetration and search decision-making. The simulation was carried out. The simulation results show that the algorithm is useful in dealing with the emergent threat and the uncertainty area diffusion, and can complete the long-range penetration and the cooperative search mission of multiple UAVs.

Research on Cooperative Saturation Attack Problems and Models of Ship-to-ship Missiles from Multi-ship Platforms

ZENG Jia-you, WANG Guo-wei, ZHONG Jian-lin, XIE Yu-peng

2014, 35(2):  256-261.  doi:10.3969/j.issn.1000-1093.2014.02.018

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For the complex cooperative saturation attack planning of ship-to-ship missiles from multiple platforms, the cooperative task levels of ship formations are divided, the cooperative task indexes are defined and the constraint conditions are given based on combat mission planning theory. A cooperative task allocation model, time cooperation model, spatial cooperation model and frequency cooperation model of ship-to-ship missiles from multi-ship platforms are built. The simulation results show that the models are feasible and effective.

Research Notes

Research on Test Methods for Special Vehicle Handling and Stability Based on Dynamics Simulation

LI Jun， YUAN Shi-hua， JU Dong-mei， LI Rui-ying

2014, 35(2):  262-267.  doi:10.3969/j.issn.1000-1093.2014.02.019

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In order to study and lay down the test methods of special vehicle handling performance and stability, the test method of special vehicle handling and stability is set up by considering the characteristics of special vehicle on the basis of the test methods in GB and ISO. The key parameters of vehicle handling and stability test are determined and analyzed through special vehicle dynamics modeling, handling and stability simulation, data processing and score evaluation. Based on this method, the test of sample vehicle is completed. The test results show that the test method is feasible, and meets the test and scoring evaluation requirements of special vehicle handling and stability.

Trade-off Analysis of Reliability/Maintainability/Supportability/Testability of Armored Vehicle Based on System Effectiveness

HAN Kun, HE Cheng-ming, LIU Wei-wei, SHEN Ying

2014, 35(2):  268-272.  doi:10.3969/j.issn.1000-1093.2014.02.020

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Trade-off analysis is a key link of quantitative requirement determination of reliability/maintainability/supportability/testability (RMST) in the process of armored vehicle demonstration, but an effective method is absent. A method to balance RMST of armored vehicle based on system effectiveness is proposed. Based on the operation and management conditions of armored vehicle, an armored vehicle system effectiveness model is set up, which is made up of three parts, including operational readiness, battle dependability and capability. Two kinds of methods are proposed for the trade-off analysis of RMST, which are trade-off analysis methods based on comparison and sensitivity, respectively. This provides an effective method to determine RMST quantitative requirement of armored vehicle, and improve system effectiveness.

Identification Method of Systematic Errors Model of a Missile-borne Radar

WANG Wen-jun， DUAN Xiao-jun， ZHU Ju-bo， ZHANG Qiang

2014, 35(2):  273-279.  doi:10.3969/j.issn.1000-1093.2014.02.021

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For the extraction and identification of systematic errors model of missile-borne radar, the independent variables are extracted for constructing a basis function, and an energy-based removing method is proposed by considering the physical mechanism and data characteristics. The effects of related factors, such as platform status and target status, on the error measurement are discussed by taking the angle-measurement errors of a missile-borne radar for example, and then a model of angle-measurement errors is build using the proposed methods, which can fit the measured data well. The result shows that the methods can be used to accurately model the systematic angle measurement error of missile-borne radar.

Extraction of Direct Signal in GSM Based Passive Bistatic Radar

LU Kai-wang, YANG Jie , ZHANG Liang-jun

2014, 35(2):  280-284.  doi:10.3969/j.issn.1000-1093.2014.02.022

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In GSM based passive bistatic radar, the antenna not only receives the direct signal and multipath signals from the host station, but also receives the signals from other base stations with the same frequency. When the data-independent beamformer is used to acquire the direct signal of the host station, it may be polluted by other signals. The direction of the direct signal of the host station can be first measured by a sub-space method. Then the direct signal is acquired by the signal blocking based adaptive beamformer. The availability of proposed method is proved by simulation data and compared in the practical data. The result shows that the proposed method is more applicable than the traditional LCMV self-adaption beam forming method.

Study of Electric Field Induced by Rotating Magnetic Dipole

ZHANG Jia-wei, GONG Shen-guang, JIANG Run-xiang, CHEN Cong

2014, 35(2):  285-288.  doi:10.3969/j.issn.1000-1093.2014.02.023

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In order to study the electric field induced by rotating magnetic propeller, a mathematical model is proposed to calculate the electromagnetic signals induced by a rotating magnetic dipole based on the Faraday’s law of electromagnetic induction. An experiment is done in the laboratory pool to test the analytical method. The results show that the signal’s order of magnitude is proportional to the rotational frequency and magnetic moment, its frequency is consistent with the rotational frequency, and the phase differences of three axis are π/2 and π, respectively. The research proves that the electric field is a part of shaft-rate electric field of ship, which complements the mechanism of production of the shaft-rate electric field, and provides a theoretical basis for the detection or control of ship’s shaft-rate electric field.