Table of Content

30 September 2013, Volume 34 Issue 9

Previous Issue    Next Issue

Simulative Analysis and Experimental Test of Composite Fragile Projectile Under Impact Dynamics

RONG Ji-li, LI Jian, LIU Xian-guang, LIN Xian-kun

2013, 34(9):  1057-1064.  doi:10.3969/j.issn.1000-1093.2013.09.001

Asbtract ( )   PDF (5116KB) ( )  

References | Related Articles | Metrics

Dynamic mechanics parameters of composite fragile projectile and aviation organic glass areobtained by split Hopkinson press bar (SHPB) experiment. The reasonable material constitutive modelsare chosen to model the fragile projectile and organic glass based on LS-DYNA software. The simulationof the fragmentation process of fragile projectile penetrating target is carried out with smoothed particle hydrodynamics(SPH) method. The influence rule of projectile frangibility and damage performance is researched by analyzing the falling speed and impacting angle of projectile, and the relevant results aresummarized by comparing the fragile and damage performances. Simulation result shows that the perform-ances of fragmentation and penetration increase as the incident velocity increases, and at the same velocity, the performances of fragmentation and penetration under normal penetrating are superior to obliquepenetrating. Numerical simulation and analysis of results offer a theoretical reference for the study offragile projectile.

Mathematic Simulation of Two-phase Flow of GasGenerator with Central Igniter Tube

WANG Shan-shan, WANG Hao, HUANG Ming, ZHANG Bo-zi

2013, 34(9):  1065-1071.  doi:10.3969/j.issn.1000-1093.2013.09.002

Asbtract ( )   PDF (3951KB) ( )  

References | Related Articles | Metrics

The two-phase flow mathematic models are developed for gas generator with central igniter tube. The one-dimensional two-phase model is used for the ignition of central igniter tube, and the two-dimensional two-phase model is used for the energy release of tubular gas generator. The coupling function of two tubes is established through exchange between gas and solid. The interior ballistic simulation software is programmed by Mac Cormack two-step scheme and is used to calculate the gas generator. The calculated results well accord with the test results, which proves that the model is right and provides important theory foundation to structure design and optimization on gas generator with central igniter tube.Meanwhile, the energy releasing course is analyzed based on the simulation results. The result shows that the uniform ignition condition is the precondition of gas generator releasing energy steadily. The ignition energy released uniformly could ensure the reliable burning of powders in gas generator and the release of controlled energy.

Synthesis and Characteristics of La_{0. 8}Sr_{0. 2}CoO_3-δand Its Effect on Combustion Property of Nitramine Modified Double-base Propellant

WEI Zhi-xian, WANG Ya-le, GAO Yuan, LIU Ji-ping,ZUO Ying-ying

2013, 34(9):  1072-1077.  doi:10.3969/j.issn.1000-1093.2013.09.003

Asbtract ( )   PDF (4248KB) ( )  

References | Related Articles | Metrics

Perovskite-type La_{0. 8}Sr_{0. 2}CoO_3-δ was prepared by a stearic acid gel combustion method in order to investigate the effect of the perovskite oxides on the combustion property of the nitramine modified double-base propellant. The obtained powder is characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM),Fourier transform infrared (FT-IR) and X-ray photoelectron spectroscopy (XPS)techniques. The catalytic action of La_{0. 8}Sr_{0. 2}CoO_3-δ on the thermal decomposition of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) is investigated by TG-DSC technique. The burning rates of nitramine modified double-base propellant at various pressures are studied to evaluate the ballistic property. The experimental results show that La_{0. 8}Sr_{0. 2}CoO_3-δ can catalyze the thermal decomposition of RDX, and the heat of decomposition can be increased by 34.7J/g by adding 2.0% (棕) of La_{0. 8}Sr_{0. 2}CoO_3-δinto RDX. Compared with basic propellant, the burning rate of propellant modified by La_{0. 8}Sr_{0. 2}CoO_3-δ increases at all the pressures. However, the burning rate increases more slowly with the increase of pres-sure, and hence the pressure index of the propellant is reduced. La_{0. 8}Sr_{0. 2}CoO_3-δ has the better catalyticaction in comparison with LaCoO₃.

Numerical Simulation of Two-phase Flow of Gas Generator with Central Igniter Tube

LI Yong-zhen, HU Wan-qiu, CHENG Xu, ZONG Zhi-wei, WANG Xue-song

2013, 34(9):  1078-1083.  doi:10.3969/j.issn.1000-1093.2013.09.004

Asbtract ( )   PDF (3336KB) ( )  

References | Related Articles | Metrics

A method which discriminates the coherent dual-source angle deception interference by using the relative difference between the co-polarization and cross-polarization components of target and interference is proposed. A model of mono-pulse polarization radar echo is established, and the co-polarization and cross-polarization echoes of the sum and difference beams are obtained. A statistic to distinguish the existence of coherent dual-source interference is constructed by using the difference between the interference and the radar target response function in the different polarization channels. A certain confidence level threshold is given according to the measured data of typical warhead and aircraft target and the simulation of coherent dual-source interference. The measured data obtained in darkroom and the computer simulation show that the algorithm is feasible and valid.

Nonstationary Clutter Suppression Based on Joint-time Secondary Data Selection

ZHAO Yao-dong, LYU Xiao-de, XIANG Mao-sheng

2013, 34(9):  1084-1090.  doi:10.3969/j.issn.1000-1093.2013.09.005

Asbtract ( )   PDF (5360KB) ( )  

References | Related Articles | Metrics

The range dependence is one of the intrinsic features for the clutter of airborne radar, which degrades the performance of conventional space-time adaptive processor (STAP). A novel algorithm of nonstationary clutter suppression, which is based on the joint-time secondary data selection, is presented. Due to the stationarity of radar echo in time domain and the slow change in the Doppler frequency with range, both the slow and quick time secondary data are used as the training samples for sub-CPI adaptive processing to mitigate the range dependence, and ultimately the loss of time aperture is decreased by summing the outputs of all the sub-processors coherently. The simulation results indicate that the algorithm can improve the precision of covariance matrix and the performance of main-lobe clutter suppression, and has a higher robustness.

Maneuvering-Deceleration Guidance Algorithm Based on Atmosphere Estimation for Reentry Vehicle

LI Qiang, XIA Qun-li, HE Jing,WEN Qiu-qiu

2013, 34(9):  1091-1096.  doi:10.3969/j.issn.1000-1093.2013.09.006

Asbtract ( )   PDF (3860KB) ( )  

References | Related Articles | Metrics

A new maneuvering-deceleration guidance algorithm based on atmosphere estimation is presented for the precise guidance and velocity control of hypersonic reentry vehicle. The maneuvering-deceleration guidance command is composed of optimal guidance command and deceleration command. The optimal guidance command is obtained by guidance law with position and impact angle constraints. Sinusoid aneuvering-deceleration command is used to minimize the position disturbance caused by deceleration. And the parameters of maneuvering command are produced from mismatch between terminal predicted velocity and nominal-velocity by numerical integration method. The atmosphere parameter identification technology is also used to improve the prediction precision. The simulation results show that the maneuvering-deceleration guidance algorithm has strong robustness against uncertain conditions; it can accomplish the integrated design of precise guidance and deceleration control efficiently.

Elastic-plastic Analysis on Dynamic Response of Arch Subjected to Explosive Impact

KANG Ting, XU Jin-yu, BAI Ying-sheng, LI Qing

2013, 34(9):  1097-1102.  doi:10.3969/j.issn.1000-1093.2013.09.007

Asbtract ( )   PDF (3574KB) ( )  

References | Related Articles | Metrics

The elastic-plastic dynamic response of arch structure subjected to explosive impact is analyzed with numerical simulation method. The dynamic buckling critical load is determined by B-R criterion. The results show that the process of the dynamic response is divided into the four typical stages: elastic vibration, elastic-plastic stable vibration, counter-intuitive dynamic response and crush failure. The counter-intuitive dynamic response is a mode of the unstable equilibrium after dynamic buckling. The results show that the longer the impact duration is, the smaller the dynamic buckling critical load is. When the impact duration changes in a range, the counter-intuitive response appears after buckling. When the impact duration is too long or too short, the counter-intuitive response will not appear. The sudden destruction occurs as soon as the buckling. The dynamic buckling critical load is equal to the dynamic failure load.

Synthesis and Characteristics of La0. 8 Sr0. 2 CoO3-δand Its Effect on Combustion Property of Nitramine Modified Double-base Propellant

WANG Jie-fang, AN Wei-guang, JIANG Yun-hua

2013, 34(9):  1103-1108.  doi:10.3969/j.issn.1000-1093.2013.09.008

Asbtract ( )   PDF (3667KB) ( )  

References | Related Articles | Metrics

The vibration equation is developed by semi-analytical finite element method. The mode-decoupling and Fourier transform are used to deal with the vibration equation, and the expression of dynamic stiffness is obtained. Considering the randomness of structural parameters, the random expression of dynamic stiffness is deduced by Taylor expansion and the random factor method. The influences of random factors on the means and variation coefficient of dynamic stiffness are discussed. The calculation results show that the standard deviation of elastic modulus random factor has a significant influence on the randomness of dynamic stiffness, and if all other factors are equal and the standard deviation of elastic modulus random factor is doubled, the decreasing ratios of all dynamic stiffness mean values in three minimum points are 46. 7%, and are 27. 4% and 3. 6% for two maximum points in proper order. Furthermore, when the variability of structural parameters belongs to week degree, the variability of dynamic stiffness in extreme points belong to moderate degree, even strong degree.

Research on Tribological Properties of WC-Co / NiCrBSi Composite Coatings Prepared by HVOF and APS at Elevated Temperature

Institute of Field Engineering, PLA University of Science and Technology, Nanjing 210007, China

2013, 34(9):  1109-1115.  doi:10.3969/j.issn.1000-1093.2013.09.009

Asbtract ( )   PDF (6529KB) ( )  

References | Related Articles | Metrics

WC-Co/ NiCrBSi composite coatings were prepared on the surface of aluminium alloy 7005 by high velocity oxygen-fuel flame (HVOF) spray and atmosphere plasma spray (APS), respectively. The microstructures of the composite coatings are analyzed, and the tribological behavior and mechanisms of the composite coatings at elevated temperature are researched. The results show that the porosity of the composite coatings prepared by HVOF is only 28. 9% of that prepared by APS. The microhardness of the composite coatings prepared by HVOF is 838. 4HV0. 5, and the thicknesses of Al and Ni diffusion layers are 13. 17 μm and 12. 55 μm, respectively, which are all higher than those of the composite coatings prepared by APS. The composite coatings prepared by HVOF have low friction coefficient and wear loss compared with the composite coatings prepared by APS. At room temperature of 25 ℃, the wear mechanisms of the composite coatings prepared by HVOF are micro-cutting wear and slight fatigue wear, and the composite coatings prepared by APS experience fatigue fracture wear. At elevated temperature of 400 ℃, the wear mechanisms of the former change into multi-plastic deformation wear and oxidative wear, and those of the latter turn into severe adhesive wear and oxidative wear.

Decision Feedback Estimation of Multiple-input Multiple-output Orthogonal Frequency Division Multiplexing Channel Based on Punching Technique Via UWA Shallow Sea

WANG Wei, QIAO Gang, WANG Yue, XING Si-yu, LIU Song-zuo

2013, 34(9):  1116-1124.  doi:10.3969/j.issn.1000-1093.2013.09.010

Asbtract ( )   PDF (5481KB) ( )  

References | Related Articles | Metrics

The technique of channel decision feedback estimation of multiple input/ multiple output orthogonal frequency division multiplexing (MIMO-OFDM) underwater acoustic communication system is studied. To overcome the disadvantage of error code propagation of channel decision feedback estimation algorithm, an improved algorithm based on channel punching technique is proposed. The difference between the received raw signal and the re-coded information signal is used to judge the criteria of channel compensation, and those uncertain sub-channels are punched and revalued by interpolation technique. The experimental results obtained with numerical simulation and tank-trial data are provided, demonstrating that the proposed algorithm can effectively confine the propagation of error code , abate the burst noise effect, track the variety of channel and significantly increase the quality of the system.

Research on Polarization Discrimination Algorithm for Coherent Dual-source Angle Deception Interference

HU Hai-ming, LI Shu-juan, GAO Xiao-chun, LI Yan

2013, 34(9):  1125-1131.  doi:10.3969/j.issn.1000-1093.2013.09.011

Asbtract ( )   PDF (4640KB) ( )  

References | Related Articles | Metrics

The material removal mechanism in the lapping process of SiC monocrystal wafer is investigated, the size distribution of abrasive particles is described by using the statistical theory, and the equation of number of active abrasive particles in the lapping process is conducted. According to the deformations of wafer-particle and pad-particle interfaces, a novel model is developed for material removal rate (MRR) in the lapping process of SiC monocrystal wafers. The influences of pad hardness, pressure and particle size on MRR are analyzed based on the model. Compared with the theoretical model, the experiment results show that the model can predict the MRR more accurate than others in the lapping process of SiC monocrystal wafers, which provides a theoretical basis and foundation for predicting and controlling MRR in the lapping process of other monocrystal materials.

Research on Reliability-based Robust Design Method for Rotation Systems of CNC Turrets

HUANG Xian-zhen, WU Mao-chang, ZHANG Yi-min, HU Nai-tao

2013, 34(9):  1132-1136.  doi:10.3969/j.issn.1000-1093.2013.09.012

Asbtract ( )   PDF (3327KB) ( )  

References | Related Articles | Metrics

A reliability-based robust design for turret rotation systems of computered numerical control (CNC) machine tools is extensively discussed by combining the reliability-based optimization design theory, the reliability sensitivity technique and the robust design method. The commercial software is used to establish a kinematic analysis model of the rotation system of the turret. The design of experiment is applied to obtain the quantitative relation between system responses and design variables, and then the artificial neural network (ANN) is used to approximate the functional relation between system responses and design variables. The reliability and reliability sensitivity analyses are performed by using the first order second moment method. Finally, a model for reliability-based robust design of the rotation system of the turret is developed. A practical engineering study indicates that the proposed method is a general and effective method for reliability-based design of the rotation system of the turret.

An Interactive Virtual Compartment Fire Extinguishing Model Based on System Dynamic Characteristic

REN Kai, YANG Li, PU Jin-yun, SU Xue-rong

2013, 34(9):  1137-1143.  doi:10.3969/j.issn.1000-1093.2013.09.013

Asbtract ( )   PDF (4945KB) ( )  

References | Related Articles | Metrics

The virtual fire extinguishing model is one of the basic computer simulating processes related to the disaster control commanding simulation training environment. Based on operational command simulation method, the conception of the potential is introduced into the interactive relationship between the disaster and disaster control measures. The nteractive confrontation between the disaster and the control measures can be seened as the potential interactions. For the parameter selection and quantization, the disaster potential and disaster control measures potential are given, and the quantizing potential scale and the calculating process are proposed. A dynamic relationship model is established. Combined with the classic fire extinguishing states, an analytical form model for confrontation relationship is proposed. According to the statistics of training results of the actual disaster control crew, the model parameters are determined. The simulation result is compared with the experiment data. The result shows that the model can be used to simulate the fire extinguishing process of virtual compartment.

Optimization Method of Carrying Spare Parts Support Project for Warship Equipment under Multi-constraints

RUAN Min-zhi, LI Qing-min, ZHANG Guang-yu, YAO Gang

2013, 34(9):  1144-1149.  doi:10.3969/j.issn.1000-1093.2013.09.014

Asbtract ( )   PDF (3465KB) ( )  

References | Related Articles | Metrics

Due to the restriction of carrying ability and storage space for support resources, the multi-constraints targets must be considered for the optimization of a carrying spare parts project. As to this problem, the optimization of warship carrying spare parts project at mission preparation phase before sailing is taken as a research background. A carrying spare parts optimization model is established on the basis of the multi-target constraints, such as mass, volume and cost of spare parts and equipment availability. The different constraint targets are transformed to the scale of spare parts resource constraint by introducing Lagrange constraint factors. Marginal algorithm is applied to solve the optimization model, and the determination method of initial factors and its dynamic adjustment policy is presented. In the given example, the calculated result is analyzed, and the feasibility of the proposed method is verified.

Research Notes

Nonstationary Clutter Suppression Based on Joint-time Secondary Data Selection

LYU Sheng-tao, LIU Rong-zhong, GUO Rui, HU Zhi-peng

2013, 34(9):  1150-1154.  doi:10.3969/j.issn.1000-1093.2013.09.015

Asbtract ( )   PDF (4507KB) ( )  

References | Related Articles | Metrics

To seek the best aerodynamic shape of S-S style wings terminal sensitive projectile (TSP), based on computational fluid dynamics and orthogonal test, the wing bent area and bent angle are optimized with source aerodynamic parameters of the S-S style TSP aerodynamic model. Then the primary and secondary relations of wing parameters which affect the aerodynamic characteristics are obtained, and one aerodynamic shape, which has the largest drag coefficient and polar torque coefficient, is determined. The results show that, compared with the initial model, the drag coefficient increases by 7. 11% and the torque coefficient increases by 15. 77%. The tower free flight tests showed that the falling speed and rota- tion speed of the optimized TSP structure are 30. 0 m/ s and 11. 5 r/ s, respectively. The falling speed, rotation speed and scanning angle of TSP stayed steady during its falling which means that the optimized aerodynamic shape can lead to steady scanning motion.

Application of Adaptive Kalman Filter in Geomagnetic Attitude Detection System

LONG Li, ZHANG He, TANG Yu-fa, XU Guo-tai

2013, 34(9):  1155-1160.  doi:10.3969/j.issn.1000-1093.2013.09.016

Asbtract ( )   PDF (4493KB) ( )  

References | Related Articles | Metrics

The measuring precision of geomagnetic attitude detection system is affected by a variety of noise sources. Firstly, an extended Kalman filter model is established by using a simplified ballistic equation of the projectile's passive period, and then the adaptive filtering process is realized through adaptive estimation of the system noise, measurement noise and steering gear noise. Finally, the adaptive filtering method is simulated. The results show that the adaptive Kalman filter algorithm has strong feasibility, and applies to the geomagnetic attitude detection system.

Performance Study on Super-reactive AlMg / KMnO₄ Thermites

ZHENG Bao-ming, JIANG Wei, CHEN Wei, LI Feng-sheng

2013, 34(9):  1161-1166.  doi:10.3969/j.issn.1000-1093.2013.09.017

Asbtract ( )   PDF (5027KB) ( )  

References | Related Articles | Metrics

Different mass fractions of AlMg alloys are prepared by mechanical ball milling. AlMg/ KMnO₄ thermites are prepared by sonication dispersion method. These thermites could be an energetic material in the field of reactive materials and explosives. AlMg/ KMnO₄ thermites with different Al/ Mg ratios are investigated by differential scanning calorimetry (DSC), ignition and combustion measurements respectively. The results show that the reaction temperatures of AlMg/ KMnO₄ decrease obviously with the higher Mg contents, the ignition temperatures decrease from 723 K to 493 K, indicating that the thermal reactivity of AlMg/ KMnO₄ thermites is better than that of Al/ KMnO₄. The combustion products of AlMg/ KMnO4 thermites contain Al₂O₃, MgO and Mn, thus Mn is produced by the thermite reaction of AlMg/ KMnO₄.AlMg alloys react with the decomposited product of KMnO₄.

Integrated Design of Interceptor Guidance and Control Considering Modeling Error

SONG Hai-tao, ZHANG Tao, ZHANG Guo-liang, YANG Wei-feng

2013, 34(9):  1167-1172.  doi:10.3969/j.issn.1000-1093.2013.09.018

Asbtract ( )   PDF (3529KB) ( )  

References | Related Articles | Metrics

An integrated control law is designed by modifying the existing modeling results and using the intelligent control method for the guidance and control of interceptor during the terminal course. While the modeling error caused by approximate linearization and ignoring couplings is taken into consideration, a model error compensation is used to modify the interceptor dynamics. A nonlinear model for the integrated guidance and control (IGC) is obtained. The adaptive dynamic surface control is proposed for the controller design of this mismatched nonlinear system. The influence of mismatched uncertainties on the system performance is eliminated, and the term explosion in traditional backstepping method is voided. The integrated control law is used to establish a direct relationship between control objective and actuators command. Compared with the controller which ignores the modeling error in interception simulation, the proposed controller shows better interception performance.

Maneuvering-Deceleration Guidance Algorithm Based on Atmosphere Estimation for Reentry Vehicle

FANG Yuan-yuan, LI Ya-an, CUI Lin, SHANG Jin

2013, 34(9):  1173-1179.  doi:10.3969/j.issn.1000-1093.2013.09.019

Asbtract ( )   PDF (4206KB) ( )  

References | Related Articles | Metrics

Background noise and reverberation interference are the main interference sources in the sonar target detection. How to reduce their effects on sonar performance effectively has been a focus of underwater acoustic signal processing. According to Volterra series theory, a nonlinear dynamic model of underwater acoustic signal is established to realize the noise reduction of background noise and the suppression of reverberation interference by predicting the underwater acoustic signal. The direct and iterative methods are used for the one-step and multi-step predictions of the underwater acoustic signal, respectively, by using the two-order Volterra adaptive filter and the singular value decomposition adaptive algorithm. The simulation results show that the iterative method has higher prediction performance and effec- tive multi-step prediction capability.

Research on Testing Firing Rate Based on Muzzle Impulse Noise

LAI Fu-wen, ZHANG Zhi-jie, LIU Jing-jiang, ZHANG Jian-yu

2013, 34(9):  1180-1186.  doi:10.3969/j.issn.1000-1093.2013.09.020

Asbtract ( )   PDF (4161KB) ( )  

References | Related Articles | Metrics

According to the same periodicity between the muzzle impulse noise and the firing sequence, a new non-contact method which tests the firing rate based on the muzzle impulse noise is put forward. Firstly, the wavelet decomposition method is used in analyzing the test curve of the muzzle impulse noise to automatically obtain the number of fired bullets, firing intervals and firing rate and the algorithms. Secondly, the factors which influence the test for maximum rate of fire are analyzed by simulating three typical noise signals of single bullet. Finally, the effect of test position on test result is studied by means of firing experiment of an automatic rifle. The simulated and experimental results show that the method can test the firing rate of more than 10 000 bullets per minute with high accuracy.

Decision Feedback Estimation of Multiple input/ Multiple output Orthogonal Frequency Division Multiplexing Channel Based on Punching Technique Via UWA Shallow Sea

ZHAO Jian-zhong, LI Hai-jun, YE Wen, WANG Hao-wei

2013, 34(9):  1187-1192.  doi:10.3969/j.issn.1000-1093.2013.09.021

Asbtract ( )   PDF (3676KB) ( )  

References | Related Articles | Metrics

An optimal configuration model of spare parts under the condition of improved spare part fill rate is established in order to overcome the disadvantage of that traditional system spare parts fill rate is prone to minimum. An improved layered margin optimization algorithm is given to improve the optimization efficiency of algorithm by using the layered optimization idea. The detailed optimization flow of the algorithm is given, and the optimization efficiency of the algorithm is analyzed in theory. The correctness and rationality of the model are proved by analyzing the calculated result of an example.

Elastic-plastic Analysis on Dynamic Response of Arch Subjected to Explosive Impact

MA Chun-mao, SHAO Yan-jun, PAN Hong-xia, LIU Yong-jiang

2013, 34(9):  1193-1196.  doi:10.3969/j.issn.1000-1093.2013.09.022

Asbtract ( )   PDF (2665KB) ( )  

References | Related Articles | Metrics

For the difficulty in predicting time between weapon failures, a grey Markov model is established based on grey model (1,1). And a combined model for the prediction of the time between failures is established by analyzing a typical failure rate curve of electronic equipment and forming a reasonable modeling background according to the characteristics of electronic equipment faults. The predicted value is compared with the real value through an instance. The result shows that the combined model can be used effectively to predict the time between failures, reduce the prediction error and improve the prediction accuracy in the case of few data, poor information and uncertainty.

Analysis of Random Dynamic Stiffness Characteristics of Supercavitating Vehicle Structure

LIU Xi-chun, ZHU Long-shi, ZHANG Wei

2013, 34(9):  1197-1200.  doi:10.3969/j.issn.1000-1093.2013.09.023

Asbtract ( )   PDF (2815KB) ( )  

References | Related Articles | Metrics

A new fuzzy inference-based wartime spares demand forecasting method is presented for the uncertainty and stage-relativity of the spares demand during multi-stage war, in which expert forecasting value and Markov forecasting value are combined. The result is obtained according to the Mamdani-style inference mechanism and defuzzification. The fuzzy set of demand is defined by linguistic variable naturally, which is introduced in Markov forecasting to describe the system state directly. The validity of the method is illustrated by an example.