Acta Armamentarii

A Probabilistic Analysis on the Damping Force of Tank Vane Damper

Dong Mingming, Gu Liang, Wang Guoli

2004, 25(1): 1-4. doi:10.3969/j.issn.1000-1093.2004.01.001

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A new static calculation method of gap produced by the dimensional tolerance, form tolerance and position tolerance was developed based on the traditional tolerance formula. The vane dumper widely used in battle tanks is used as an example. Comparison of the computed value based on the model with the experimental data shows that the mathematical model is validated. With the model, the contribution of each tolerance to the damping force variation can be worked out. It is seen that the damping force variation can be greatly decreased only by reducing some key tolerances.

A Study on Heat Transfer Emulation within an Armored Vdiiele

Zhao Yixian ,Bi Xiaoping,Liu Xiaxia,Wang Pukai

2004, 25(1): 5-8. doi:10.3969/j.issn.1000-1093.2004.01.002

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simulation for heat transfer within an armored vehicle was given. The heat transfer model of armored vehicle was built up using the lumped parameter method, and a computational program was worked out. The status of heat of a certain type of armored personnel carrier when navigating on the sea under steady conditions was computed. Temperatures and heat characteristics of each compartment were computed. The results were in good accorded with the experimental data.

A Study on the Vibration Qiaracteristics of Multiple Launch Rocket System

1:Yun Laifeng, Rui Xiaoting, Lu Yuqi,Wang Gonglian, Zhang Wei;2:Zhao Kesheng

2004, 25(1): 9-13. doi:10.3969/j.issn.1000-1093.2004.01.003

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Vibration characteristics of multiple launch rocket system(MLRS) were studied from the as?pects of theory, simulation and test. Using the multibody system transfer matrix method (MSTMM), problems of computation in the vibration characteristics of MLRS as a coupled rigid — flexible multibody sys?tem was resolved and modal test was completed. The results obtained by computation and modal test show to be in fine agreements.

Development of a New Type Gas-Driven Two-Stage Light Gas Gun

Zhang Dezhi, Tang Rundi, Lin Junde,Zhang Xiangrong,Zhu Yurong

2004, 25(1): 14-18. doi:10.3969/j.issn.1000-1093.2004.01.004

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Use of two-stage light gas guns is one of the techniques extensively used to achieve hyperveloc?ity projectiles. A new type of gas-driven two-stage light gas gun for hypervelocity impact research is intro?duced. The device was made up of a compressed gas gun as the first-stage arive and a second-stage launch?ing apparatus that can be disassembled. Functions of the compressed gas gun was preserved and relevant techniques were discussed e. g. those regarding how to improve the energy utilization ratio, how to decrease the second-stage launching impact force, how to reduce the cost of testing and how to improve experimental efficiency. The 0.7-gram projectile has been accelerated to a speed of 7.2km/s, using 20MPa N2 in first- stage, and 0.1MPa H2 in the pump tube.

Numerical Simulation of Muzzle Blast Flowfidds of Large Caliber Guns

Le Guigao, Ma Dawei, Feng Yong, Shi Guohua,Zhu Zhongling, Song Xiaofeng

2004, 25(1): 19-22. doi:10.3969/j.issn.1000-1093.2004.01.005

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The three-dimensional compressible flow equations were solved using the Osher，s scheme. The flow phenomena of a gun's muzzle were calculated and analyzed. In the construction of difference algo?rithm, the work of calculation is simplified by the combination of the finite volume discretization method and Riemann’s solver. Firstly, the numerical test of the supersonic flow through a wedged wind tunnel at Mach number Ma∞ ニ2.0 was done. The numerical results agree well with the theoretical analysis. Sec?ondly ,the gun’s muzzle flow problem was calculated. Ihe flow parameter distributions oi the whole flow- field around the muzzle including the carriage surface were obtained and the flow process was described in detail.

A Study on the Destruction Effect of the Split instance of the Ammunition “AHEAD” to a NfissiIe Target

Li Xiangdong,Jiao Xiaojuan

2004, 25(1): 23-25. doi:10.3969/j.issn.1000-1093.2004.01.006

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In order to study the influence of the split distance of the ammunition “AHEAD” to its dam?aging efnciency, spacial distribution of sub-projectiles after separation of the ,shell and the density distribu?tion of sub-projectiles resulting from single and multiple firing in the interception plane were analyzed. The damage assessment model of the projectile to the target was then built up. Damage to a typical target (ARM) was calculated using the Monte Carlo process. The result shows that the damage probability de-creases with the increase of the split distance when the target's distribution is less than that of the projectile' s. On the other hand, the damage probability will assume a peak value when the target's distribution is more than that of the projectile's. This peak value is the optimal split distance. The result of calculation al?so shows that the split distance will have the more obvious influence to the damage when the target s distri?bution become wider apart.

Long-Time Storage Performance of Steel-Welded Cartridges

Luo Tianyuan,Zhang Lunwu

2004, 25(1): 26-29. doi:10.3969/j.issn.1000-1093.2004.01.007

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Welded steel cartridges used in huge numbers demand a close attention to its long-time storage performance. The present article summarizes the test results of welded steel cartridge concerning their cor?rosion, stress corrosion and galvanic corrosion as well as surface anti-corrosion technics through artificial light ageing,heat ageing,salt spray tests?stress corrosion tests, typical natural environment storage and ex-posure tests and so on. Conclusions have been arrived at that the welded steel cartridge have on the whole good long-time storage performances; and that their manufacturing and painting processing techiques are successful.

Catalysis of Metallic Salts of Tetrazales on Gxnbustion of RDX-CMDB Propellant

1:Zhao Fengqi, Chen Pei, Li Shangwen ,Wang Baicheng;2:Du Heng, Deng Minzhi

2004, 25(1): 30-33. doi:10.3969/j.issn.1000-1093.2004.01.008

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The effect of Pb( II ) , Cu( II ) and Sr( II ) salts of tetrazales on the combustion properties of RDX-CMDB propellant was investigated. It was found that the Pb( II ) salts of 5-methylene bistetrazale and 5-penyltetrazale possess better catalytic effects for the propellant. When the Pb( II) or Cu( II) salt of tetrazale is used together with other organic Pb( II) or Cu( H ) salts, the burning rate of the propellant will be increased, and a low pressure exponent zone is obtained. The experimental results showed that these salts are good energetic catalysts.

A Study oh the Sdf-Sensitive Characters of Expanded Ammonium Nitrate

Chen Tianyun

2004, 25(1): 34-36. doi:10.3969/j.issn.1000-1093.2004.01.009

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Expanded ammonium nitrate (AN) manufactured with surfactant and vacuum crystallizing technology was studied. The activation energy of heat decomposition, crystal structure, micro-pore diame?ter and volume of the expanded AN were measured. Compared with regular AN, crystal pellets of expanded AN has lower activation energy of heat decomposition reaction, numbers of “micro air-pores”，larger micro?pore volume and honeycomb structure. Expanded AN has self-sensitive characters. Its reaction activity, re?action velocity and reaction completeness are increased. Self-sensitive AlN can be used as an ideal oxidizer for energetic materials.

Multiple Thresholding for Fignter Infrared Image Sequence

1：Tu Jianping；2：Peng Yingning

2004, 25(1): 37-40. doi:10.3969/j.issn.1000-1093.2004.01.010

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Aimed at the infrared image sequence of a fighter’s target, a new segmentation method using multiple thresholds was presented. Based on the statistics characteristic oi image sequence measured in real time and the proportion between an object and its background in the last frame image, the range of two thresholds of the current frame image can be determined. Then the two optimal thresholds can be calculated using the criteria of maximum entropy and genetic algorithm. Experimental results show that the method can properly segment a lighter target and its trail-spout tube as a special component in real time，so it can be applied to rLIR image guidance and ATR.

A Novd Beam Hopping Communication Scheme for Military CooiMunication

Hu Honglin, Shang Zheng, Zhu Jinkang

2004, 25(1): 41-45. doi:10.3969/j.issn.1000-1093.2004.01.011

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Digital beamforming (DBF) techniques significantly improve the performance of military com?munications systems. However, if the communication is strongly jammed in the direction of the transmitted beam, the directional jamming will severely degrade the performance of the systems. In order to solve this problem, the paper proposes a novel beam hopping (BH) military communications scheme. Results of anal?ysis in the average SINR performance show that compared with the conventional single beam (SB) and multi —beams (MB) communication schemes, the new beam hopping communication scheme is capable of efficiently combating the directional jamming, and utilize fully the directional gain of the beams of transmit?ters and receivers. Moreover, the new BH scheme can letdown the intercept probability of communication in a degree. Therefore, it is a promissing military communications scheme with a good performance — cost trade-off.

Fractal Antenna Array with Fractal Element and Its Full Wave Analysis

1:Wang Hongjian;2:Gao Benqing

2004, 25(1): 46-49. doi:10.3969/j.issn.1000-1093.2004.01.012

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Two kinds of fractal antenna arrays FYAGI and FLPDA were proposed. These two kinds of arrays are both made up of fractal element antenna (FEA)，but with the same space distance as their corre?sponding YAGI and logarithmic periadic dipole arrays in the Euclidean domain. The method of moments (MoM) performs the task of evaluating each of the antennas. The result shows that the resonant frequency of the FYGAI is lower than that of the regular YAGI antenna, whilst the bandwidth of the FLPDA is wider than that of the regular LPDA. The patterns and gains of the FYAGI and FLPDA are almost the same as those of their corresponding YAGI and LPDA antennas on their resonant frequencies.

Multi-Resolution Fusion in the Ultrasonic Inspection of Defects in Heat-Insulation Layer Adhesives

YangFengbao, Han Yan,YangFanglin

2004, 25(1): 50-52. doi:10.3969/j.issn.1000-1093.2004.01.013

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In the detection of adhesive status between the heat-insulating layer and the case of a solid rocket motor through ultrasonic C-scanning, there exists a contradiction between the high-resolution probe that was easily disturbed by noises and the low-resolution probe where the detective precision is low. An image fusion method was suggested for the two types of probes. Steps and algorithm of image fusion with multi-resolution of two-dimensional wavelet transform were discussed, and a practical example was given. It is shown that an image with high-resolution and high signal to noise ratio can be attained.

Digital Smulation of Pressure on a Rudder along with the Velocity of a Missile

Jiang Yi, Liu Qi, Zhang Xiaolin

2004, 25(1): 53-55. doi:10.3969/j.issn.1000-1093.2004.01.014

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In order to secure a highpressure source for the operation of the rudder, a punching rudder is generally used in anti-tank missiles. Its key characteristics lies that the flow velocity is made use of to pro?duce a high pressure for rudder operation when an anti-tank missile is flight. Because the velocity varies in the flight of an anti-tank missile, the pressure in the pump of the rudder is also changing. It is of signifi?cance to calculate the pressure in the design of rudders or anti-tank missiles. A method of calculating three- dimensional Navier-Stokes equations was presented. The appropriate range of velocity of anti-tank missile fiignt was discussed.

Fuzzy Multiattribute Method of Emitter Threatening Grade Evaluation

1:Jiang Ning;2:Hu Weili;3:Sun Ao

2004, 25(1): 56-59. doi:10.3969/j.issn.1000-1093.2004.01.015

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Emitter threatening grade evaluation is a particular subject in electronic countermeasures. It is the foundational work m jam resources allocation and assistant decision making. Based on an analysis of the threatening grade evaluation process now in use in navy scoutplanes weights of threatening factors for the emitter using the object consensus ranking principle were proposed. Membership functions of threatening factors for the emitter were determined by fuzzy sets, and a new way of radiant imperilment grade evalua?tion was presented. Criterion of emitter threatening grade evaluation was given. This is shown to be feasi?ble and effective with a concrete example. The method may present a new way in threatening grade evalua?tion, and consequently enable the settlement of more complicated threatening environment.

A New Estimation Method for Reliability

Han Ming

2004, 25(1): 60-64. doi:10.3969/j.issn.1000-1093.2004.01.016

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In the past years, some achievements have been made on Bayesian methods used for solving reliability problems. In this paper Bayesian estimation method of parameters was extended and a new esti?mation method of product reliability put forward; viz. the expected Bayesian estimation method. Defini?tions of expected Bayesian estimation and expected Bayesian estimation for product reliability were given. To provide convenience in comparison, hierarchical Bayesian estimation of the product reliability was given. Calculations were performed on practical problems, showing that the proposed Bayesian estimation method is feasible and easy to operate.

An Algorithm for the Two--Center Problem

Zhou PeiDe

2004, 25(1): 65-68. doi:10.3969/j.issn.1000-1093.2004.01.017

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All kinds of the basic cases of two-center problems and the construction of their matched-pair circles were discussed. Some properties of the matched-pair circle were then introduced, followed by an al?gorithm for solving the two-center problems. The governing idea is that the convex hulls covering a set of points must cover the set of points. Through the algorithm can be obtained a set of points covered by two e- qual radii and the smallest circle. Moreover,the complexity of the algorithm was analyzed and its correctness discussed. A practical example was given.

Stability Bounds for Uncertain Matrices in a Set of Subregions

1:Wu Qinghe;2:Zhang Dongwen

2004, 25(1): 69-72. doi:10.3969/j.issn.1000-1093.2004.01.018

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Research on the robustness bounds for matrices with unstructured uncertainty was addressed. The upper bounds on the spectral norm of the unstructured uncertain matrices were determined. These bounds can ensure that the eigenvalues of uncertain matrices lie in a specified region D-LMI region of the complex plane. The LMI characterizations for intersection or union of LMI subregions were given and the stability bounds for these LMI regions sets can be computed, finally,three examples for single LMI region, intersection and union of LMI subregions were provided to illustrate the algorithm for bounds. The approach is proved to be more effective when compared with previous methods.

A Theoretical Model for the Projectile-Barrel Coupling Problem

Ma Jisheng, Wang RutLin

2004, 25(1): 73-77. doi:10.3969/j.issn.1000-1093.2004.01.019

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A dynamic model for the projectile-barrel coupling problem was set up with Huston’s method based on Kane’s equations. The barrel in this model is considered as a cantilever beam attached to a moving support. Elastic deformation of the barrel is calculated by means of the preceding N orthonormal modals of the cantilever beam. The projectile is regarded as a rigid body and the center of rotation of the band trans?lates along the axis of the barrel while rotating around this axis. Eccentricity of the center of mass of the projectile is taken into account. Relationship between rotation and translation of the projectile is determined by the pitch of the rifling. Powder gases pressure, irictional force and frictional torque are applied on the projectile and the barrel. This model can be used to analyze accurately the process of launching.

Applications of SiGe Technology in RF Fields

1：Meng Lingqin；2：Fei Yuanchun

2004, 25(1): 78-81. doi:10.3969/j.issn.1000-1093.2004.01.020

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This paper outlines the tendencies and advantages of SiGe technology. It is shown that SiGe BiCMOS technology and Siue HBT are very promising for applications in RF and microwave circuits owing to their superiorities in frequency performance, noise performance, etc. At the same time, market priori?ties of these products put a premium on their low-cost/low-power/high-volume implementation of their characteristics. Drawing an analogy to digital integrated circuit technology, SiGe appears to be the optimum choice for RF applications. It might follow the same path that digital IC implementations have thus far fol?lowed toward CMOS-with costs dropping dramatically as the level of integration increases. It is seen that SiGe devices will have their wide foreground in the fields of RF and microwaves.

Preparation of Nanometer Sze a-Fe2O3 and Its Catalysis on the Tliermal Deocxnposition of Aminoiiium PerehloMte

Yang Yi, Li Fengsheng,Tian Linghua

2004, 25(1): 82-85. doi:10.3969/j.issn.1000-1093.2004.01.021

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Nanometer α-Fe2〇3 catalysts are prepared by hydrolization in high temperature. The precipi?tator of NaOH, (NH4 )2C03 and urea are used to compare their effects in the process of hydrolization. Nanometer sizer, TEM and XRD are employed to test the profiles and diameters of the product particles. Test results indicate that the products are nanometer size α-Fe2〇3 with narrow diameter distribution and good dispersion. The catalyst is mixed with ammonium perchlorate (AP) in 1.0%wt. DTA is employed to analyse the thermal decomposition of the mixture and the pure AP sample. The result implies that the ther?mal decomposition peak of the sample added with the nanometer α-Fe2〇3 catalyst is markedly ahead of the pure AP sample. Among these mixtures added with the nanometer material, the smaller the particle size of catalyst the more ahead tended to be the thermal decomposition curve peak of AP. And the high and low temperature decomposition curve peaks of AP mixed with the catalyst precipitated by urea are 780C and 9. 6b C ahead respectively. The mechanism of catalysis when precipitated by urea and the distinct catalytic ac?tion of the particles on the thermal decomposition of AP are analyzed.

A Study on Low Exhaust Emissions from a Gasoline and LPG Convertible-Fuel Motorcycle

1：DengBaoqing,Gong Changming,Sun Yan；2：Liguang，Liu Zhimin

2004, 25(1): 86-89. doi:10.3969/j.issn.1000-1093.2004.01.022

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The construction and performance of a newly developed gasoline and LPG convertible-fuel mo?torcycle was introduced. Engine power output, motorcycle dynamic performance, fuel economy, exhaust e- mission and acceleration noise were measured on an engine dynamometer test stand, chassis dynamometer stand and on the road. Test results show that the engine power of the developed LPG and the motorcycle dynamic performance are kept at almost the same level with that of the gasoline prototype. The gasoline fu?el economy was compared with that of LPG engine. For the convertible-fuel motorcycle fueled with LPG， the exhaust emissions is lower than those of KUROH limits, while in the case of gasoline they are close to the EURO II limits. Maximum acceleration driving noise of the gasoline and LPG convertible-fuel motorcy?cle meets the motorcycle national stipulations for 2005.

A Study on the Port/Starboard Discrimination of Towed Line Army Made Up of Hydrophone Doublets Based on Model of Noise Correlation

1:He Xinyi, Jiang Xingzhou;2:Zhang Chunhua

2004, 25(1): 90-94. doi:10.3969/j.issn.1000-1093.2004.01.023

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Aiming at the port/starboard blur problem of a towed line array sonar, the paper presents a new towed line array structure： towed line array made up of hydrophone doublets using the model of noise correlation to accomplish port/starboard discrimination. After a theoretical analysis and simulation, it is proved that a towed line array made up oi nydrophone doublets based on the model of noise correlation can solve the port/starboard blur problem under single frequency, multi-frequency and wide band conditions. The structure of towed line ar?ray made up of hydrophone doublets is simpler than that made up of hydrophone triplets. A towed line array made up of hydrophone doublets has less requirements in its installation, is cheaper, has simpler algorithm, and is easily realized. It is an effective measure for practical towed line array port/starboard discrimination.

Measurement of Surfaces Having Large Radius of curvature

1:Yang Zhiwen, Di Xu;2:Wang Jinjiang

2004, 25(1): 95-97. doi:10.3969/j.issn.1000-1093.2004.01.024

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Measurement of curved surface having large radius of curvature is a problem for a three coordi?nates measuring macnine. The measured surface could not be larger than the machine and should be set at a level position. An industrial measurement system with electronic theodolites as sensors is a new way to solve this problem. It belongs to the non-contact measurement systems, so the measured piece could be freely set. The system has larger measurement range and higher precision. Erected curved surfaces have been measured and some techniques of measurement were discussed in the paper. The measured results directly- given from the measurement system are the three coordinates of sampling points. Analysis of the relation?ship between these coordinates ana the surface to be measured are first necessary. According to the surface characters, the standard deviation of all sampling points coordinates are selected to evaluate its surface preci?sion. Then, the measurement system is set up. Measurement precision and surface characters should be considered before setting up the system. Results of measurement show that these measures could achieve purposes in curved surface measurement and have wide applications.

A Millimeter Microwave Sensor Used for Detecting and Identifying Airdrome Runways

1：Li Xingguo,Wang Lei;2:Yan Jinhai,Lü Fusheng

2004, 25(1): 98-101. doi:10.3969/j.issn.1000-1093.2004.01.025

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A pill millimeter microwave sensor technique for detecting and identiiymg airdrome runways by three beams was discussed. The sensor combines a two beam radiometer working in conical scan with an integrated radiometer and radar along the same beam. Distance of sensor measurement and method of target acquisition — identification were given. It is shown that the MMW sensor can accurately identify airdrome runway by merging the ability of radiometer identiiymg different material and different size into MMW sen?sor with the ability of radar measuring distance. The conical scan project is easily realized than imagination and fit for smart ammunition pill application.

Experimental Study on the Strain HSstory of Cnticai Section during a Noniial Penetration of Tungsten Alloy Shell into a Concrete Target

Cheng Xingwang, Wang Fuchi, Wang Lu, Li Shukui

2004, 25(1): 102-105. doi:10.3969/j.issn.1000-1093.2004.01.026

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Normal penetration of a tungsten alloy shell into a concrete target was performed and the strain history of the critical section of the shell was obtained with the aid of an onboard recording system. Although the tungsten alloy shell undergoes a high stress during penetration, the test results indicate that the shell keeps its integrity. The strain history achieved may provide a base in shell design and verify theo?retical models and numerical simulations of tungsten alloy shell impacting and penetrating normally into con?crete targets.

A New Micro Liquid Crystal Display for Use in Mlitary Helmets

Zhou Hong, Shen Yuhong, Zhang Xiaoying ,Chen Xiao

2004, 25(1): 106-109. doi:10.3969/j.issn.1000-1093.2004.01.027

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Liquid-crystal display has seen very rapid development due to its excellent properties，vid. its high definition, low power consumption, light weight, no radiation et al. The paper introduces a new mi?cro liquid crystal display (Micro-LCD) for use in a military helmet adopting the virtual-display technology. It is used to convey messages of digital image, data and text for the individual’s system. Through it can be seen the information in figures, maps of the battleground，his and the enemy’s positions etc. The kind of micro-LCD uses a dynamic array liquid crystal material，where as the micro liquid crystal piece closely past?ed onto an integrated circuit silicon slice. TThrough the electric circuits, the liquid crystal materials are di?rectly driven. It uses the LED as the illuminant, and lets the R, Lr, B light source to produce the full-col- orea images on the micro-LCD according to order. Ihe micro-LCD also includes a special optical system ac?cording to the principle of vision of human eyes. So a visual image can be seen.

Temperature Effects in the Dynaznic Fracture Behaviors of Ship-Buildiiig Steel

Zhang Xiaoxin, Liu Ruitang

2004, 25(1): 110-112. doi:10.3969/j.issn.1000-1093.2004.01.028

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At different temperatures the dynamic fracture toughness of a ship-building steel was tested and measured using the Hopkinson bar testing equipment. The rule of transition of dynamic fracture tough?ness versus temperature was first obtained，and the morphology of dynamic fracture at different tempera?tures was analyzed. Under a nigh loading rate, the characteristic of transition rule of dynamic fracture toughness versus temperature shows an upper and a lower shelf，and shows the sharp characteristics of duc?tile-brittle transition for the steel. With decreasing temperature the appearance of fracture of the steel is one of micro void coalescence, and then it has mixed cleavage and cleavage. The security assessment and the be?havior oi ductile-Brittle transition of the steel were obtained quantitatively.

Experimental Study of the Formation of Intake Swirl in the Cylinder of a 4-Valve Diesel Engine

Mei Deqin,g Wang Zhang

2004, 25(1): 113-115. doi:10.3969/j.issn.1000-1093.2004.01.029

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Hot wire anemometer was applied to test the air flow field within the cylinder of a 4-valve diesel engine by steady flow measuring equipments. The process of formation of intake swirl in the engine was investigated. Characteristics of the air flow in the cylinder were discussed. In addition, the develop?ment and evolution of air flow in the cylinder were analyzed. It is shown that at the outlet of cylinder head air flow changes strongly and there is high turbulent intensity so it is difficult to be come an obvious swirl. Down the cylinder, air flow affected by the turbulence continuously attenuates and shapes itself into a steady swirl.

Application of Amplitude Spectrum in the Ultrasonic Inspection of Adhesive Quality in Multi-Layered Structures by-the Oblique Echo Method

Zhang jitang, Lu Hongnian

2004, 25(1): 116-120. doi:10.3969/j.issn.1000-1093.2004.01.030

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When the adhesive quality in multi-layered structures (steel shell, insulation layer and under lying layer) in airboume solid rocket motors is inspected through oblique ultrasonic pulse echo in immer?sion, the amplitude spectrum extrema between echoes are used to get signal characters, in order to eliminate signal overlapping in the time field. The phenomenon of unevenly distributed extrema in practical testing, some measures were introduced to improve precision in the extraction of characters. As a result the signal- to-noise ratio is increased and the image quality is much improved.

Optical Method for the Position-Attitude Determination of Space Vehicles

1:Du Xiaoping, Zhao Jiguang;2:Cui Zhanzhong

2004, 25(1): 121-123. doi:10.3969/j.issn.1000-1093.2004.01.031

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To realize autonomous control, precise measurement of relative states (relative position and at?titude) between two space vehicles remains one of the most important requisites for formation-fiymg of spacecrafts. An optical method for testing the relative position and attitude between spacecrafts was pro?posed ，based on computer vision and imaging theory. The framework of the testing system and the working process was first introduced, and a quaternion method for measuring the relative position and attitude based on the coordinates of the feature points on the target body was deduced. Possible causes of error of the test?ing system was then analyzed. As quaternion theory and CMOS camera are used in testing the relative states, the system possesses the following advantages： simple and rapid algorithm, compactness and light weight, high precision, and low power consumption. The proposed method can be widely used in measur?ing the relative position and attitude between space targets in cooperation.

Product Data Management Systfems Oriented to Gun Design Departments

Wang Yongjuan, He Lei, Xu Cheng

2004, 25(1): 124-128. doi:10.3969/j.issn.1000-1093.2004.01.032

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Principles of product data management require that bills of materials be formed in the depart?ment of gun design. Through studies in product structure management，product configuration manage?ment, workflow and version management，all reasonable modes of management were chosen and coopera?tion work teams were set up in the process of gun design based on their characters. In this paper, the PDM oriented to the department of gun design was developed. C++ language was applied to program the corre?sponding function models.

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