Table of Content

01 March 2013, Volume 34 Issue 3

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Experimental Research on Shock-produced Deformation of Thin-walled Metal Tubes Subjected to the Magnetic Dynamic Load and Electrical Explosion

XIA Ming, HUANG Zheng-xiang, GU Xiao-hui, ZU Xu-dong, WANG Ye-zhong, JIA Xin

2013, 34(3):  257-262.  doi:10.3969/j.issn.1000-1093.2013.03.001

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The magneto-hydrodynamic explosive loading simulation platform is used to study shock-pro- duced deformation of thin-walled metal tubes subjected to the magnetic dynamic load and electrical explo- sion, discharge waveforms of the high current and final deformation of the tubes manufactured with differ- ent materials and structures are acquired. The result shows that the high current discharge characteristics could be described well by RLC circuit process when the power is capacitor bank, the shock-produced deformation of same structure tubes is mainly affected by loading mode, and materials are heat up signifi- cantly by the Joule heat and more easily deformed, but high temperature may lead to gasification and magnetic field shaped charge jet(MSCJ) could not be formed. Low melting point or low ductility materi- als are not suitable for MSCJ made, compared with Al, the Cu material is better, compared with normal tube, truncated cone tube is more easily controlled to form MSCJ.

Equivalence Method for the Dynamic Loading of Concrete Slab Subjected to Explosion

ZHANG Xiao-wei, WANG Qing-tao, ZHANG Qing-ming, SHI Peng, ZHOU Xu

2013, 34(3):  263-268.  doi:10.3969/j.issn.1000-1093.2013.03.002

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Based on the consistency of dynamic response, an equivalence method is proposed in which the explosive load acting on a concrete slab is simplified to be uniform triangle pressure load without as- cending time. By using dimensional analysis, the maximum momentum of the structure and its arrival time are used as medium parameters, the relations of the peak overpressure and duration of the equivalent load with the explosive mass and distance are obtained. Afterwards, a series of numerical simulations are conducted, based on which the constants in the empirical formula are determined. Finally, the dynamic response of the structure subjected to the equivalent load and that caused by the true explosive load are compared by means of numerical simulations, which show good agreement and verify the validation of this method.

Applied Research on Eliminating the Hazard of Residual Propellant Gas in the Chamber with Inert Gas

XU Bin, LIU Zhi-tao, JI Dan-dan, WANG Hao-yu, LIAO Xin, WANG Ze-shan

2013, 34(3):  269-275.  doi:10.3969/j.issn.1000-1093.2013.03.003

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In order to eliminate the flammability hazard of residual propellant gas in the chamber, gas bottle filled with CO2 is equipped. The combustible gas content of the residual propellant gas is calculated by gas constitution model, and then the quantity range of CO2 to make the combustible mixed gas to an incombustible one is obtained through literary calculation. Considering the parameters of gas bottle used and other conditions in practice, the theoretical feasibility analysis and experimental verification of gas bottle filled with mass range of CO2 calculated are carried out, and the results show that the gas bottle with mass range of CO2 obtained can not only be opened and deflate completely, but also effectively elim- inate the flammability of the residual gas. Meanwhile, the elimination effect of residual gas becomes more obvious with the increasing of the mass of CO2 added, which means the maximum quantity of CO2 calcu- lated should be applied in practice.

Constitutive Relation and Fracture Criterion of 2A12 Aluminum Alloy

ZHANG Wei, WEI Gang, XIAO Xin-ke

2013, 34(3):  276-282.  doi:10.3969/j.issn.1000-1093.2013.03.004

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The quasi-static and dynamic material properties, including the strength relation and fracture criterion, from room temperature to 250 益are investigated using a universal testing machine, a torsion testing machine, a split Hopkinson tension bar and the Taylor impact test. The Johnson-Cook constitutive relation with a modification on the strain hardening term and the Johnson-Cook fracture model with a mod- ification on the temperature softening item were proposed to fit the test results. The material constants were calibrated by a combination of experimental tests and numerical simulations. It is concluded that the strain strengthening and temperature softening effect is obvious, while the strain rate hardening effect is not significant; the fracture strain increases with temperature and strain rate and decreases with stress tri- axiality.

Experimental and Numerical Study on the Shock Initiation of PBXC03 Explosive under the Different Loading Pressure

WEN Li-jing, DUAN Zhuo-ping, ZHANG Zhen-yu, OU Zhuo-cheng, HUANG Feng-lei

2013, 34(3):  283-288.  doi:10.3969/j.issn.1000-1093.2013.03.005

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The shock initiation experiments on the PBXC03 explosives in two different formulations, namely, the medium and the coarse one, are performed to obtained in-situ manganin piezoresistive pres- sure gauge data at various shock pressure. The loading technique of explosive plane-wave lens and the at- tenuation technique produced by both air-gap and Al-gap are used in the one-dimensional Lagrangian ex- perimental system. The Numerical simulation on the shock initiation of the two kinds of PBXC03 explo- sives are performed by using the two-dimensional hydrodynamics software DYNA2D. The computational propagation trajectory and pressure growth process of the shock front agree well with the experimental da- ta, and the computational run-distance-to-detonation points show good agreement with previously pub- lished Pop-plot data, which confirms that the mesoscopic reaction rate model used in this paper is reason- able.

Research on Gun Breechblock Life Based Crack Formation and Propagation

LI Kui-wu, NING Bian-fang, ZENG Zhi-yin, WANG Zai-sen, ZHANG Jun-ling

2013, 34(3):  289-293.  doi:10.3969/j.issn.1000-1093.2013.03.006

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Some automatic weapon breechblock formed 1mm depth crack after firing of 523 rounds during the finalized test. In order to estimate whether the residual life satisfies the requirements for the use of the breechblock, the crack formation and propagation life has been studied using analytical and numerical method. Considering the effect of the roughness level, the fatigue life is no less than 1 650 rounds under the conditions of normal temperature and standard charge. It is greater than the design target. Based on the simulation result, we analyzed the influence factors of the breechblock fatigue crack formation life and took the measures to reduce the breechblock roughness level. The breechblock fatigue life has been en- hanced to more than 1 800 rounds.

Modeling and Simulation of Vessel Propeller Cavitation Noise

XIE Jun, DA Liang-long, TANG Shuai

2013, 34(3):  294-300.  doi:10.3969/j.issn.1000-1093.2013.03.007

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In order to solve the problem of modeling and simulation of continuous spectrum of propeller cavitation noise and its modulation spectrum characteristics, four circumstances are categorized to conduct theoretical analysis on synthetic power spectrum of each cavitation bubble noise, and to perform simula- tion tests based on theoretical study and test results on cavitation noise continuous spectrum, randomicity, psuedo - periodicity of collapse of each cavitation bubble, and the waveform of its radiated noise, during which time domain Monte Carlo simulation model is proposed for cavitation noise continuous spectrum. The theoretical analysis and simulation results both show that the frequency domain offset of propeller cav- itation noise modulation characteristics is resulted from instability of cavitation noise continuous spectrum shapes.

A Method of Navigating Pose Controlling System Design for Underwater Vehicle Based on Variable Structure Control

ZHANG Xi-yong, WANG Shu-zong, LI Zong-j

2013, 34(3):  301-309.  doi:10.3969/j.issn.1000-1093.2013.03.008

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The navigating pose of underwater vehicle is difficult to be controlled because there exist cou- pling between pitching, yawing, rolling and uncertain disturbance caused by varying ocean current, so traditional control technology cannot obtain controlling objective. For solving the difficulty existed in un- derwater vehicle爷s pose decoupling controlling, the subsystem status equation of pose controller of under- water vehicle adopting variable structure control is constructed through constructing state equation of un- derwater vehicle pose moving subsystems. Theory analysis and simulation show that the designed control- ler makes pose angle track course angle of trajectory steadily and has good robustness for uncertain dis- turbance caused by varying ocean current, and achieves decoupling controlling between underwater vehi- cle pose moving subsystems.

Prediction and Numerical Simulation of Cavitation Noise Line-spectrum Frequency Induced by Underwater Counter-rotation Propeller

WANG Shun-jie, CHENG Yu-sheng, GAO Xin

2013, 34(3):  310-317.  doi:10.3969/j.issn.1000-1093.2013.03.009

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Underwater high speed target counter-rotation propeller always works at cavitation condition, the cavitation noise line-spectrum is due to the interaction between fore and aft propeller, and the interac- tion between the fore or aft propeller and wake of the ship. According to the acoustic analogy equation of Goldstein and making vacuole as one part of propeller, the academic prediction of counter-rotation propel- ler cavitation line-spectrum frequency is presented. The far field sound pressure expression of monopole sound source is deduced, and the line-spectrum prediction frequency is gained. The counter-rotation pro- peller cavitation is numerically simulated using Schnerr-sauer cavitation model, RNG k-着turbulence mod- el and dynamic mesh model. The results shows that the predicted cavity shapes of DTMB4381 propeller agrees well with the experimental observation and numerical simulation result on open literature, and the counter-rotation propeller cavitation line-spectrum frequency is got by this method which agrees with the result of Academic prediction absolutely.

Effect of Thickness and Hardness and Their Interaction of Rubber Layer of Stern Bearing on the Friction Performance

QIN Hong-ling, ZHOU Xin-cong, YAN Zhi-min, LIU Zheng-lin, ZHAO Xin-ze

2013, 34(3):  318-323.  doi:10.3969/j.issn.1000-1093.2013.03.010

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Rubber layer of ship stern tube water-lubricated rubber bearings can be easily deformed elas- tically under certain load, and can cause the change of water wedge between the bearing and the shaft journal, which affects the friction performance of the bearing system. Thickness and hardness are the main structural factors that affect the deformation of the rubber layer. To determinate the influence of these two factors and their interaction, tests were carried out on the test rig SSB-100 by test blocks, and corresponding friction coefficient were recorded. Then two-factor variance analysis with interaction was done with the experimental data. The results show that among the effect of rubber layer thickness, hard- ness and their interactions of test blocks on the friction properties, the rubber layer thickness is the most significant, followed by hardness, then the interaction of thickness and hardness. Thus, in the design, rubber layer thickness should be guaranteed as priority.

Fatigue Life Prediction of Crankshaft Repaired by Arc Spraying

ZHANG Guo-qing, LI Guang-wei, WANG Cheng-tao, XU Bin-shi

2013, 34(3):  324-331.  doi:10.3969/j.issn.1000-1093.2013.03.011

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In order to quantitatively study crankshaft fatigue life repaired by arc spraying, the tensile test of the 48MnV with 3Cr13 coatings is conducted, the method proposed by Baumel Jr. and Seeger is used to estimate fatigue parameters of the material. And the fatigue life of crankshaft repaired arc spraying is calculated and assessed. The loads in each link neck are obtained through dynamic simulation, among which spring units are used to simulate the actual elastic support status in the spindle neck and the boundary conditions are adjacent cranks interaction. Then, the Crankshaft fatigue life is calculated using multiaxial damage model, respectively using the normal strain law, the SWT-Bannantine approaches, shear strain method and Fatemi-Socie method. Finally, the engine bench strengthen tests of the new axis, respectively 500 h, 1 000 h and 3 000 h are conducted. And the crankshaft after the engine bench strengthen test is cut into cranks on which the fatigue tests are carried out. The test results match the cal- culation results.

Integrated Management Algorithm of Jamming Resources in Multi-beam Jamming Systems

SONG Hai-fang, WU Hua, CHENG Si-yi, CHEN You

2013, 34(3):  332-338.  doi:10.3969/j.issn.1000-1093.2013.03.012

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To study the integrated management of jamming resources in advanced airborne multi-beam jamming systems, the model of threat assessment is built by means of multiple attribute decision making and the model of jamming task request is set. According to the jamming resources constraints, radar tar- gets classification are achieved. When the jamming task request is beyond the jamming beams, the C-means algorithm to integrate the jamming tasks is used. The algorithm of jamming resources distribution in multi-beam jamming systems is proposed. Target classification and task integration can optimize the use of jamming resources and improve the standard of intelligence in multi-beam jamming systems.

Mission Decision-Making Method of UAV Considering Target Importance and Historical Mission Trust Value

HUANG Chang-qiang, TANG Chuan-lin, HUANG Han-qiao, WANG Yong, DU Hai-wen

2013, 34(3):  339-345.  doi:10.3969/j.issn.1000-1093.2013.03.013

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To cope with the problem of multi-UAVs cooperative mission decision-making, a composite method based on considering target importance and UAVs爷mission trust value is proposed. The method composes of two parts including improved fuzzy matter-element target importance evaluation and UAVs爷 mission trust value evaluation based on historical mission trust value. In the first part, the improved fuzzy matter-element target importance evaluation method is presented by improving the structure of matter-ele- ment, employing uniform membership grade function and introducing the subjective coefficients. In the second part, a multi-UAV trust network model is built up based on UAVs爷historical mission data; the computing method of direct trust value, indirect trust value and integrated trust value computation by u- sing entropy theory is put forward. According to the evaluative results of the above two parts, the current mission decision-making can be obtained. The results of simulation demonstrate that the proposed method is efficient and useful, and can meet the need of UAV mission decision-making.

Design of Simulation Experiment Based on the Mind Map

CHEN Xin, LANG Guo-xing, DUAN Feng,MA Hua-dong

2013, 34(3):  346-352.  doi:10.3969/j.issn.1000-1093.2013.03.014

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The traditional experiment design methods cannot meet the complex requirements of weapon e- quipment system demonstrations. Therefore, we put forward the mind map based simulation experiment aided design method. Firstly, we use the ontology method to describe the mind mapping ontology and simulation results. Then, we establish the mapping algorithm from mind mapping to the simulation experi- ment scheme. Afterward we implement the automatic generation of simulation experiment based on mind mapping. Finally we demonstrate the feasibility of the method based on the digitized army capability re- search problems.

Engine Fault Diagnosis Utilizing Adaptive Morphological Lifting Wavelet and Improved Non-negative Matrix Factorization

LI Bing, XU Rong, JIA Chun-ning, GUO Qing-chen

2013, 34(3):  353-360.  doi:10.3969/j.issn.1000-1093.2013.03.015

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Signal processing and feature extraction are two of the most significant steps for engine fault di- agnosis. In order to overcome the limitations of the traditional wavelet and morphological wavelet, a new lifting scheme named adaptive morphological gradient lifting wavelet (AMGLW) is presented, which can select between two filters, the average filter and morphological gradient filter, to update the approximation signal based on the local gradient of the analyzed signal. Thus the impulsive components can be enhanced and the noise can be depressed simultaneously by the presented AMGLW scheme. Furthermore, the im- proved non-negative matrix factorization (INMF) is utilized to calculate the features for engine faults clas- sification. The vibration signals acquired from an engine with five working states are employed to validate the proposed engine signal processing and feature extraction scheme.

Separate Estimation for Corrections of Camera Parameters and Coordinates of Ground Points

YU Jia-xiang, ZHAO Xiao-zhe, LIANG De-qing, JIANG Lu-dong, ZHOU Jing

2013, 34(3):  361-364.  doi:10.3969/j.issn.1000-1093.2013.03.016

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In the geo-location method based on common points in multiple aerial images, the computa- tional efficiency of the simultaneous least square estimate used to reckon the corrections of aerial camera parameters and ground point coordinates degrades rapidly with the increase of the number of common points. To solve this problem, a novel algorithm is presented to separately estimate the corrections of camera parameters and ground point coordinates by considering the feature that the coefficient matrices of the corrections of camera parameters and ground point coordinates are independent. It is theoretically based on the separate least square estimation, and calculates the corrections of camera parameters and ground point coordinates in every iteration step alternately. In the iteration procedure, the coefficient ma- trices are parted to decrease their dimension numbers. Such partition improves the efficiency of correction computation. Simulation results show that the separate algorithm has higher computational efficiency than the present simultaneous algorithm, without degrading the precision of the corrections.

Comprehensive Review

Research Status of Tungsten and Its Alloy Coating

ZHANG Xue-hui, LIN Chen-guang, CUI Shun, LI Zeng-de, HU Xiao-kang

2013, 34(3):  365-372.  doi:10.3969/j.issn.1000-1093.2013.03.017

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Tungsten, with high chemical stability and high temperature characteristics, is widely used in modern industry and military field. However, the resources of tungsten are non-renewable, the price be- comes more and more expensive and its processing is difficult. With various kinds of surface engineering technology, coating tungsten and its alloy on matrix material surface,can give the matrix materials excel- lent physical and chemical properties, not only broaden its application scope, but also save tungsten re- sources. This paper summarized the main coating technical means of tungsten and its alloy at home and abroad, the characters and research status of these technologies are introduced,the development direction of the coating is also prospected.

Research Notes

Research on the Structural Design of Gimbaled Warhead Killing Device

SHI Zhi-bin, GAO Min, YANG Suo-chang, WEI Bao-hua

2013, 34(3):  373-377.  doi:10.3969/j.issn.1000-1093.2013.03.018

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Adopting directional warhead is one of main ways to improve the operational effectiveness. For the high power, designing the main parameters of the gimbaled warhead killing device is necessary. The static initial velocity and static spray angle of fragments are confirmed according to the operation require- ment of anti-aircraft missile. The charge to metal ratio (mc / mf) of cylindrical front-fragments warhead is calculated by using Gurney formulas. Different cone angles of fragment beam are achieved by choosing different initiation modes, and the cone angles are ensured by concave fragment-layer design. The prelim- inary radius of the layer is acquired, which is the key parameter of the killing device. The calculation re- sults about fragment-field density and fragment residual velocity indicate that the maximum distances at which the fragment-field density is enough are respective 71. 0 m and 23. 2 m when the cone angle are 10毅 and 30毅under dynamic explosion condition. The two modes of the warhead can be adopted at different operational distance, and the warhead has a higher capability to damage TBM.

Study on Dynamic Performance of Multiple-DOF Servo Mechanism爷s Load Simulator System

SUN Meng, LI Chang-chun, YAN Hao, LIU Xiao-dong, ZHANG Jin-ying, MU Dong-jie

2013, 34(3):  378-384.  doi:10.3969/j.issn.1000-1093.2013.03.019

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Aiming at load simulating problem of the thrust vector control (TVC) system in launch vehi- cles, a new load simulator structure and its mathematical model are presented. The influence of main pa- rameters on system爷s dynamic performance is analyzed by simulation. Building a prototype experiment system, multiple DOF load property is showed in a sweep frequency test. Simulation and experiment veri- fy the feasibility of this load simulator structure, which lay a foundation for optimizing design parameters of the thrust vector servo mechanism and developing load simulators of heavy launch vehicles爷servo sys- tems.