Table of Content

27 February 2015, Volume 36 Issue 2

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Paper

Simulation and Experimental Research on Oil Flow Loss of Diesel Engine at Plateau

ZHANG Chang-ling, LIU Fu-shui, SHANG Hai-kun, WANG Pei, ZHANG Zheng, WANG Yan

2015, 36(2):  193-199.  doi:10.3969/j.issn.1000-1093.2015.02.001

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For low oil pressure in diesel engine at plateau, the lubrication system of the diesel engine is researched through experimental test, theoretical analysis and CFD simulation. The results show that the ambient pressure affects the basic pressure in the whole oil passage. The inlet pressure of the oil pump equivalently decreases with the increase in altitude, resulting in lower ambient pressure . In this condition, asuction appears in the pump, which may reduce the main oil pressure significantly. As the flow rate keeps constant, the pipe flow loss decreases gradually with the increase in pipe diameter.Though the flow loss rate becomes smaller,the right angle junction has great influence on the flow loss, and for r/R≥ 1.5, the change of flow loss tends to be stabile. The plateau test results show that the engine oil pressure of the improved scheme is increased by about 30% at low rotating speed, and the oil pressure is increased by more than 50% at medium and high rotating speeds.

Research on Tribological Behaviors of Laser Surface Textures under Dry Sliding

QI Ye, CHANG Qiu-ying, WANG Bin, LI Juan

2015, 36(2):  200-205.  doi:10.3969/j.issn.1000-1093.2015.02.002

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Surface of specimen is textured with a LM-YLP-20F-Ⅱ laser marking machine to develop regularly arranged micro-dimples. Ring-block line contact friction tests are performed to study the influence of laser textures’ area density on friction and wear behaviors under dry sliding. The morphologies of textures are examined with a stylus profiler and a scanning electron microscope. A simplified finite element contact model of friction pair with surface textures is developed to simulate sliding friction, and the stress distribution is obtained to analyze the effects of surface textures on tribological properties. The results show that the effect of laser surface texturing on the surface hardness of specimen is remarkable. Both the wear losses of two mating specimens are reduced compared with non-textured specimens when the area density of laser surface textures is less than 20%, and the wear rate of textured specimen still goes down. However the wear rate of the mating specimen goes up when the area density of laser surface textures is over 20%. High stress location and magnitude shift with the change in the dimples on contact surfaces, which is beneficial to wear resistance.

Numerical Research on Rotating Band Engraving Process of a Large-caliber Howitzer

SUN Quan-zhao， YANG Guo-lai， WANG Peng， GE Jian-li， XIE Run

2015, 36(2):  206-213.  doi:10.3969/j.issn.1000-1093.2015.02.003

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A finite element model of the rotating band engraving into the forcing cone section of gun tube is established to explore the mechanism of engraving process of rotating band of a large-caliber howitzer under launch conditions. The dynamic engraving process of the rotating band is studied through numerical simulation, and the maximum resistance, engraving pressure and projectile velocity at the corresponding time are obtained. The deformation and groove formation processes of the rotating band are analyzed. The dynamic engraving resistance of the rotating band, the engraving pressure and movement of projectile are also calculated. The calculated results show that the rotating band undergoes plastic deformation and material flow, and forms the grooves on it due to ductile fracture, where shear failure is dominant. The rotating band has a layered feature after engraving, and the plastic strain in the band is small. The heat generated by adiabatic deformation of the rotating band is not enough to melt it. The simulation results of the deformation of the rotating band show good agreement with the test data from the recovered projectile.

Research on Firing Precision Comprehensive Compensation Method of Self-propelled Anti-aircraft Gun

LI Kui-wu, PEI Yi-xuan, HUO Yong-mou

2015, 36(2):  214-219.  doi:10.3969/j.issn.1000-1093.2015.02.004

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To improve the firing precision of self-propelled anti-aircraft gun, a real-time comprehensive compensation method is proposed. The main factors effecting on the firing precision of anti-aircraft gun and the influence principle are discussed based on the weapon system structure. On the basis, an error comprehensive compensation model is built by combining with closed loop fire control method for the relevance of the fire control resolving error, and the previous fire control resolving error character is used to compensate the following fire control resolving error to improve firing precision. The theoretical computation and test data show that the proposed method can be used to improve the firing precision of self-propelled anti-aircraft gun in the case of the original weapon equipment state.

State Forecasting Research of Air-defense Rocket Launcher AC Servo System Based on Chaotic Neural Network

HU Jian, MA Da-wei, YAO Jian-yong, LIU Long

2015, 36(2):  220-226.  doi:10.3969/j.issn.1000-1093.2015.02.005

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To predict the system nonlinear and non-stationary conditions more accurately, a method of chaos prediction based on chaotic neural networks is introduced to predict the velocity of the air-defense rocket launcher AC servo system, which paves the way for the trend prediction of system nonlinear and non-stationary conditions. C-C method is used to select the proper embedding dimension and time delay. The phase space of system is reconstituted using experimental data of system’s irregular movement and is analyzed. The context neurons of output layer are added to the original Elman network, and the self-feedback gain coefficients are trained as connective weight, which could strengthen the nonlinear approximation ability of Elman network. Then a model of chaotic neural network based on the improved Elman network is set up. The predictions based on the maximun Lyapunov exponent and chaotic neural network are performed, respectively. The predicted results show that the prediction based on the chaotic neural network has a higher accuracy, which makes the trend forecasting of the system more effectively.

Research on Recoil Process of Electromagnetic Railgun

SHI Jiang-bo， LI Bao-ming

2015, 36(2):  227-233.  doi:10.3969/j.issn.1000-1093.2015.02.006

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The railgun recoil motion characteristic in launching is analyzed. And the recoil motion can be divided into three periods by armature position: armature launching in bore period, residual electric energy release period and inertia recoil period. The motion of each period is decomposed into free recoil motion and restrain recoil motion. The barrel's recoil motion characteristic in each period is analyzed. The recoil motion law of each period is solved using the motion equation and the force balance equation based on the internal ballistic calculation results and the design parameters of railgun. Taking a certain diameter electromagnetic railgun for example, on the premise of 10 kN for initial recoil resistance force, and 20 mm for total recoil distance, recoil resistance constant is calculated as 22.728 kN, the total recoil time is 92.32 ms, and the recoil motion curve is obtained. The calculation method and results can provide the basis for designing the braker and recuperator of railgun.

Research on the Influence of Magnesium Combustible Liner on Dynamic Deformation and Combustion Stability ofComposite Base Bleed Propellant Grain

NIU Gong-jie, QIAN Jian-ping, QIAN Li-xin, WU Zhi-hui, CAO Cheng-zhuang, LI Ding-peng

2015, 36(2):  234-241.  doi:10.3969/j.issn.1000-1093.2015.02.007

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To solve the problems of that composite base bleed propellant grain (CBBPG) is crushed and unstably combusts during launching, a protection strategy is proposed by directly installing a magnesium combustible liner (MCL) with temporary strength protection and auxiliary combustion in the inner hole of CBBPG. The FEM analysis model of CBBPG’s launching process in extreme working conditions is established by using ABAQUS, and the dynamic shooting contrast verification test is done. The simulation results show that MCL can effectively prevent CBBPG from excessively deforming during launching. At the same time, the test results show that the average velocity of the projectiles with MCL is increased by 4.97 m/s, and the combustion consistency and combustion stability of CBBPG are both improved.

Numerical Research on Flow Characteristics of Kerosene Gel in Different Kinds of Pipeline Based on Power-law ConstitutiveModel

CAO Qi, FENG Feng, WU Xiao-song, CHEN Chao

2015, 36(2):  242-249.  doi:10.3969/j.issn.1000-1093.2015.02.008

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In order to optimize the design of kerosene gel supply pipeline and tapered injector, the power-law constitutive model is used to build a solution method of two-dimensional/three-dimensional incompressible steady flow. The flow characteristics of kerosene gel are numerically studied based on a SIMPLE algorithm. The analytical solution of parameters of propellant in straight round pipe and the kinetic energy correction coefficient of laminar flow are presented. The results show that the plunger flow area of straight round pipe is fixed when pipe diameter is unchanged. To reduce the average apparent viscosity of the injector outlet cross section, the length of outlet section needs to be decreased. The reasonable contraction angle of injector is about 40°. In elbow pipe, The secondary flow in the form of double vortices exits in elbow pipe. The asymmetries of shear rate and apparent viscosity are more significant than the asymmetry of flow velocity.

Cloud Ammunition System

LI Jie， YOU Ning， LI Bing， GUAN Zhen-yu， YANG Cheng-wei

2015, 36(2):  250-254.  doi:10.3969/j.issn.1000-1093.2015.02.009

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The development of cloud computing technology and its wide application in the military field make the large-scale intelligent ammunitions possible to combat cooperatively. In order to deepen and expand the connotation of intelligent ammunition cooperative combat, the concept of cloud ammunition system is proposed from the perspective of system science. The system connotation is discussed based on synergetic theory, and the main features of the system are analyzed in terms of mechanism and mathematical logic. Finally, the main functions of the cloud ammunition system are provided, and the problems which need to be addressed and the development directions of the cloud ammunition system are discussed.

Ballistic Deflection on Oblique Penetration of Projectiles with Different Noses

GE Chao， DONG Yong-xiang， LU Zhi-chao， FENG Shun-shan

2015, 36(2):  255-262.  doi:10.3969/j.issn.1000-1093.2015.02.010

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The ballistic trajectories of projectiles with differently shaped noses and composite material noses obliquely penetrating into steel target are researched. The deflection torque during the penetration is also studied. The results show that the ballistic deflection of projectile with truncated-oval nose is smaller, its performance against the ballistic degradation is high and its penetration trajectory is stable. The nose made of high-density and high hardness tungsten composite material shows the better penetration performance and the smaller ballistic deflection angle. The deflection relevance of oblique penetration ballistic trajectory is obtained based on the relation between the oblique torque and the oblique angle. It can be seen from orthogonal experiment simulation that the shape of the nose, the material of the nose and the penetrating velocity have the effects on the oblique angle.

Research on the Trajectory of a Rocket-towed Net System

HAN Feng， CHEN Han， CHEN Fang

2015, 36(2):  263-271.  doi:10.3969/j.issn.1000-1093.2015.02.011

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The lengthwise deployment of a net towed by a rocket is studied. The problem is simplified as two-dimensional motion, and a multi-rigid-body dynamic model is built. The dynamics equation of the multi-body system is built using Kane's method and is derived with numerical computation method. The calculated results which contain the trajectory and tension of the rocket-towed net system are in agreement with the simulation results.

A Molecular Dynamics Simulation of Solvent Effects on the Crystal Morphology of FOX-7

REN Xiao-ting, YE Dan-yang, DING Ning, HE Jin-xuan, LU Yan-hua, LEI Qing, GUO Ying-yuan

2015, 36(2):  272-278.  doi:10.3969/j.issn.1000-1093.2015.02.012

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The crystal morphology and crystallization behavior of FOX-7 are calculated by using growth morphology methods based on growth morphology module of Materials Studio, and the specific crystal face distance, area and attachment energy are obtained. The dominant crystal faces and their surface structures are predicted by calculation. A double-layer structure model is established. Molecular dynamics simulations are performed on the crystal faces of FOX-7 in contact with solvent, and the influence of the solvent environment on the crystal morphology, which provides a theoretical support for the selection of crystalline system, is studied. Uniform grained FOX-7 without edge and corner and with small aspect ratio is prepared by recrystallization in DMF/acetone solvent. The experimental result is consistent with the simulation result.

Dynamic Response of Cold Launching Equipment to Prepared Launching Site Subjected to Loading

ZHANG Zhen-dong， MA Da-wei， REN Jie， HE Qiang， ZHU Zhong-ling

2015, 36(2):  279-286.  doi:10.3969/j.issn.1000-1093.2015.02.013

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In order to research the dynamic response of old launching equipment to prepared launching site subjected to loading, the loading is regarded as multi-circle distributed force, and the expression of force is derived based on Hertz contact theory. Based on the governing differential equation of Winkler foundation model, the differential equations of two-layer plate are improved by adding the subgrade reaction into the two-parameter foundation model. Then the expression of launching site deflection under single-circle distributed force is deduced by using Fourier integral transformation and triangular series methods. The analysis formula of settlement under multi-circle distributed force could be got by using linear superposition method. For the sake of settlement of launching site, a co-simulation dynamic model of launching equipment including site is built by ADAMS software and Simulink software. Analysis results of the settlement of circle center in every contact area show that the settlement of contact area at the base is larger and has great impact on the deflections of the latter two contact areas of support disk, the settlement interact between support disks should be ignored because of small order magnitude.

Research on Target Acquisition Probability in the Terminal Guidance of Guided Munition

LIU Xiao, TANG Sheng-jing, ZHU Da-lin, GUO Jie

2015, 36(2):  287-293.  doi:10.3969/j.issn.1000-1093.2015.02.014

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The addition of the midcourse guidance in the guided munition attack and the geometrical position between the missile and the target during the missile flight are studied. The key analysis focuses on the angle of the target intercepted from the seeker when the missile attacks the ground fixed target. The fast calculation method and the analytic method are put forward. In the result of the approximate calculation which is from the space distribution ellipsoid and the ground distribution ellipse, the view angle calculation formula is derived. Furthermore, a general mathematical model to get the target acquisition probability from the view of statistical probability is created. According to the 3σ principle, whether to add the midcourse guidance is decided. The zero-effect miss and the maneuvering ability of the guided munition are researched. The results show that the maneuvering ability of the guided munition covers the zero-effort miss. The confidence interval of the view angle first decreases and then increases when the distance between the seeker and the target decreases. Finally, the influences of different disturbance factors on the view angle's confidence interval are calculated. The calculated results show that the wind in x direction has more influence on the view angle than the wind in z direction.

A Real-valued Sparse Representation Method for DOA Estimation with Unknown Mutual Coupling

WU Zhen， DAI Ji-sheng， ZHU Xiang-lin， ZHAO De-an

2015, 36(2):  294-298.  doi:10.3969/j.issn.1000-1093.2015.02.015

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The paper presents a real-valued sparse representation method for DOA estimation in the presence of unknown mutual coupling. Utilizing a certain unitary transformation and taking advantage of the special structure of mutual coupling matrix (MCM) for uniform linear arrays (ULAs), we are able to convert complex-valued manifold matrices of ULAs with unknown mutual coupling into real ones. Due to this transformation, the computational complexity can be decreased by a factor of at least four. Moreover, the proposed method is expected to have a better noise suppression, as it exploits an additional optimal weighting matrix. Thus, the proposed method outperforms the original one, especially when signal-to-noise ratio (SNR) is low. Simulation results verify the efficiency of the proposed method.

Experimental Investigation on the Supercavitation models Penetrating into Solid Medium and the Influence Factors

CHEN Cheng, YUAN Xu-long, LIU Chuan-long

2015, 36(2):  299-304.  doi:10.3969/j.issn.1000-1093.2015.02.016

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To obtain the supercavitation models penetrating into solid medium and the influence factors of mechanical properties, including the penetration velocity, penerator shape and ventilation, a series of experiments are carried out using a transparent silicone box. The penetrators are launched by air cannon, and the penetration processes are recorded by a high speed camera. The penetration velocity is obtained through image processing and analysis. In the first experiment, the penetration phenomenon of supercavitation models was successfully obtained. And then a series of experiments for different head-shapes of penetrators were carried out at different penetration speed. The effects of the influence factors on the supercavity profiles and the deceleration characteristics are analyzed. Referring to underwater ventilation supercavitation concept, a new penetrator whith ventilation is designed to test the supercavitating penetration under ventilation , which finally confirms that ventilation is benefit for the generation of supercavity and helps to prolong the penetration depth.

Research on Shadow Enhancement for Synthetic Aperture Sonar Images

ZHANG Peng-fei, LIU Wei, JIANG Ze-lin, LIU Ji-yuan, ZHANG Chun-hua

2015, 36(2):  305-312.  doi:10.3969/j.issn.1000-1093.2015.02.017

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Synthetic aperture sonar needs to collect the echoes from a target at different locations, which blurs the contour of shadow cast of targets. The conventional methods cannot obtain good effects because of lack in exploitation of synthetic aperture principle. A rigorous derivation of fixed focus shadow enhancement (FFSE) algorithm is presented, and time domain, frequency domain and range-Doppler domain are conducted. For synthetic aperture sonars, many receivers are used to increase efficiency. Non-uniform fast Fourier transform (NSFFT) is used to eliminate non-uniform sampling in azimuth direction, and then shadow enhancement can be applied in range-Doppler domain. The method is applied to lake-trial data set and sea-trial data set. Results show that the shadows of objects are enhanced evidently, which is great significance to image segmentation and target identification.

Numerical Analysis of Dynamic Process of Humid Hydrogen-oxygen Combustion and Water Mixing Process

ZHANG Fang-fang， ZHANG Zhen-shan， WANG Jin-zhong, LIU Jia

2015, 36(2):  313-320.  doi:10.3969/j.issn.1000-1093.2015.02.018

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Dynamic performance of humid hydrogen-oxygen non-premixed combustor has a direct effect on the safety of underwater thermal power system. To study the dynamic characteristics of this combustor, the masses and temperatures of gas phase and liquid phase in the combustor are calculated by the laws of conservation of mass and energy, and the interaction of gas phase and liquid phase is considered by the droplet evaporation mode. A dynamic process model of this combustor is established based on the air-in and air-out mass flows of working substance which are calculated by nozzle principle. The dynamic process simulation of a combustor is realized by use of the calculation program based on the dynamic model. The results show that the simulation curves consist with the variation law of parameters during the dynamic process. The temperature in the combustor drops and the pressure in it rises with the increase in flow of mixing water.

Numerical Analysis of Comfort of Military Helmets Based on Inverse Dynamics

YANG Yang, XU Cheng, GUAN Xiao-rong, WANG Ya-ping

2015, 36(2):  321-326.  doi:10.3969/j.issn.1000-1093.2015.02.019

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A “helmet-head-neck” musculoskeletal model is established to investigate the effect of helmet on soldier’head and neck muscular activities. The muscle activation is used as a comfort evaluation criterion and the muscle redundancy problem is solved by the “minimum-fatigue” criterion.The influences of the helmet weight, center of mass and tightening force of the lower jaw belt on the activities of muscle groups of head and neck are studied based on inverse dynamics. The results show that the weight andcentroid position of helmet have the effects on muscle activation in the sagittal plane. The neck muscle activation has little change when additional lateral bending moment is less than the corresponding threshold in the coronal plane. Enhancing the tightening force is advantageous to enhance the stability of helmet,which increases the activation of jaw muscles.The proposed musculoskeletal model can be used to calculate the change of muscle activation under different situations and conduct a quantitative analysis for helmet design.

An X-ray Online Detection Method for the Distribution of Grain Inner Holes

WANG Zhi-qiang, LIU Bin, PAN Jin-xiao, HAN Yan, CHEN Ping

2015, 36(2):  327-331.  doi:10.3969/j.issn.1000-1093.2015.02.020

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A novel method is proposed for detecting the distribution of inner holes of extrusion moulding propellant grain online by reconstructing X-ray projection information obtained in multi-angle based on the sinusoidal projection and experience. The experimental result shows that the method not only reduces the acquisition angles of view and the detection cost, but also achieves the requirement of online detection, and ensures the accuracy of the distribution information of inner holes. When the number of angles of view is greater than or equal to six, the detection accuracy of the method can reach 0.01 mm.

The Exact Lower Confidence Limit of Reliability for Normal Stress and Normal Strength

RONG Ji-li， SONG Qian-qiang， YANG Guo-xiao， ZHANG Tao

2015, 36(2):  332-336.  doi:10.3969/j.issn.1000-1093.2015.02.021

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For stress and strength obey normal distribution and their distributed parameters are unknown, some researchers have given approximate lower confidence limits of its reliability under these conditions. But the error of approximately confidence limits is large in the case of small samples. Based on stress-strength model and relevant statistical knowledge, the exact lower confidence limit of its reliability is presented. The proposed method is compared with three kinds of approximate limits methods. The result shows that no matter large or small the size of the sample is, the accuracy of the method mentioned in this paper is higher than those other three methods. When the size of the sample is small, it is recommended to use this proposed method; when the size of the sample is large, these three methods can be used for approximate calculation. This proposed method provides a new approach for the assessment of the reliability.

Optimal Cooperative Ordering Policy for Spare Parts Inventory with Two Supply Modes

WANG Shen， LI Qing-min， LI Hua， RUAN Min-zhi

2015, 36(2):  337-344.  doi:10.3969/j.issn.1000-1093.2015.02.022

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In order to satisfy the demands of inventory system on the spare parts, an emergency order is implemented to cover the shortage of regular order and reduce equipment downtime in case of stock-outs. A cooperative-ordering model, which takes compound fill rate as the constraints and expected cost per unit time as objective function, is established to solve the joint optimization problem for multi-location order policy in the two supply modes. A heuristic algorithm is developed to optimize the proposed model on basis of Lagrangian factor and policy-iteration algorithm. The Monte-Carlo simulation model is presented to prescribe the demand and order behaviors. The analytical model is compared with genetic-algorithm-optimized simulation model in a set of designed experiments. The results show the analytical model derives near-optimal solution and operates with high efficiency.

Cavitation Flow Simulation and Structural Optimization of Hydraulic Spool Valve V-throttle Groove

SUN Ze-gang, XIAO Shi-de, WANG De-hua, XU Ming-heng

2015, 36(2):  345-354.  doi:10.3969/j.issn.1000-1093.2015.02.023

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The cavitation flow of hydraulic spool valve V-throttle groove is simulated analyzed using the hybrid mixture model based on Fluent software and standard κ-ε turbulence model. The position and size of cavitation in V-throttle groove are different no matter how the opening is small or large. The obvious effects of structural parameters W and D on the cavitation flow of the V-throttle groove are found through dynamic mesh simulation analysis. According to above V-throttle simulation result, the Kriging agent model is established using constant regression model by taking the parameters W and D as independent variables and the maximum value of the gas volume fraction of V-throttle groove as target value, and Gauss function as correlation function. The Kriging agent model for the small or large opening is solved by using improved genetic algorithm, and the optimal V-throttle structure can restrain the cavitation performance significantly.

Static Radical Stiffness Characteristics of Non-pneumatic Mechanical Elastic Wheel

ZANG Li-guo， ZHAO You-qun， LI Bo， WANG Jian， FU Hong-xun

2015, 36(2):  355-362.  doi:10.3969/j.issn.1000-1093.2015.02.024

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A model based on Timoshenko curved beam is established to study the radial stiffness of mechanical elastic wheel, and the finite element method and prototype test are used to verify the model. The wheel loads supported on the rigid hub hanging in the middle of wheel are analyzed. The stiffness characteristics are illustrated for wheel with different structures by means of the qualitative analysis. The value of radial stiffness is determined by the structural characteristics and properties of elastic wheel disk and hinge groups. Parametric analysis of elastic wheel disk stiffness, hinge groups materials and sizes, which would affect radial stiffness, is done using the nonlinear finite element model. The results indicate that, as the number, cross-sectional area and Young's modulus of hinge increase, the radial stiffness increases nonlinearly. When wheel stiffness is small and other design variables are unchanged, the stiffness variation of elastic wheel disk is approximately equal to the radial stiffness variation of the wheel.

Real-time Embedded Software Architecture Modeling and Reliability Estimation Based on Time-extended Petri Net

XU Yu-tang, YIN Yong-feng, SUN Jing, ZHANG Chi, LIU Bin

2015, 36(2):  363-373.  doi:10.3969/j.issn.1000-1093.2015.02.025

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Software reliability is one of the most important quality indices in software quality evaluation. With the development of software engineering and component reusing, the reliability analysis based on software architecture has become a researching hotspot. This paper puts a research on existed architecture-based reliability estimation models at first, then proposes existing architecture based reliability estimation types and typical models, putting forward the shortage of these models as well. As Petri net has a well expansibility and descriptive power of concurrency and asynchronism, this paper focuses on the research of Petri net model, divides transition into time transition and instant transition, and adds time-related reliability—time-delay reliability and temporal reliability, by this means establish the software architecture modeling. The reachable state transition matrix is set up and the system reliability estimation is made by studing the relationship between component state and system reachable state. At last, the method is used in a avionics embedded software for architecture modeling, reliability estimation and error analysis, proving the effectiveness and accuracy of this method.

Research Notes

Responses of HMX-based and PETN-based Explosives to Electrostatic Discharge

LI Zhi-peng, LYU Zi-jian, WEN Wen, LONG Xin-ping, HUANG Yi-min

2015, 36(2):  374-378.  doi:10.3969/j.issn.1000-1093.2015.02.026

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The responses of high-density HMX-based and PETN-based explosives to electrostatic discharge(ESD) are tested by JGY-50 electrostatic spark tester. Two discharge modes including impenetrating discharge and surface discharge are employed to simulate the different ESD scenarios. The results show that the response of high-density explosives include heat and shock effects. The heat effect of PETN-based explosive and the shock effect of HMX-based explosive dominate under ESDs. No detonation is probably observed because there is less accessible surface area and low permeability of high-density solid explosive allowing little convective burning, and the energy of ESD can not be coupled effectively to high-density solid explosives.

Investigation into Load Characteristics of Submarine-launched Missile Being Ejected from Launch Tube Considering theAdapter Elasticity

LIU Chuan-long， ZHANG Yu-wen， WANG Ya-dong， QI Xiao-bin

2015, 36(2):  379-384.  doi:10.3969/j.issn.1000-1093.2015.02.027

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A cross flow is applied on a missile, which has a great influence on the stage of out of tube, when a missile is launched from the concentric canister launcher during the movement of submarine. This leads to a series of launching safety and load problems. In order to obtain a higher degree of confidence of load characteristics out of tube both in time and spatial dimensions and use the less hypotheses, an unsteady simulation model which can solve the flow field and missile motion in consideration of the adapter elasticity and 3 DOF motion of missile is proposed and established by the first time. The effect of bubble elasticity on the load characteristics is analyzed. The motion parameters, load characteristics and adapter deformation during the launching of missile from launch tube are obtained. The results show that the oscillation resulting from the cross flow has an adverse effect on missile launching.