Table of Content

30 September 2009, Volume 30 Issue 9

Previous Issue    Next Issue

Paper

Research on Axis Damper of Steering Wheel of Armored Vehicle Based on Simulating

WANG Guo-sheng, WANG Zhe-rong, Ma Guoxin

2009, 30(9):  1153-1158.  doi:10.3969/j.issn.1000-1093.2009.09.001

Asbtract ( )   PDF (6022KB) ( )  

References | Related Articles | Metrics

When armored vehicle runs on the field road, the vehicle’s hand-transmitted vibration at the steering wheel is very hard. Based on the biomechanics character and the human-mechanical engineer?ing require ment such as manipulative convenience, the author simulated the damping effect of the damper in axes with the software of MATLAB and optimized the designed parameters in accordance with the simulated result from views of the multiple suojects. The simulated result shows that the damper can decrease the vehicle’s hand-transmitted vibration greatly when running on the stone road, and improve its manipulative comfort; under a certain stiffness coefficient, there is a optimal damping rate, which changes in a small range from 0.2 to 0.3, to make the damping effect in the first phase optimum. And lastly it was testified that the adoption of semi-active vibration absorbing on steering wheel is not needed.

Finite Element Analysis of 3D Transient Eddy Field in Electromagnetic Railgun

LIN Qing-hua, LI Baoming

2009, 30(9):  1159-1163.  doi:10.3969/j.issn.1000-1093.2009.09.002

Asbtract ( )   PDF (5008KB) ( )  

References | Related Articles | Metrics

The 3D transient eddy of railgun with solid armature was analyzed, the Lagrangian formula?tions of electromagnetic diffusive processes with moving coordinate based on quasi-static Maxwell’s e- quations were established by magnetic vector and electric scalar potentials. Lagrangian description of field variables exhibits several advantages in modeling electromagnetic diffusive problems with moving coordinate, 1.e. the numerical instability at hypervelocity can be eliminated, the computational cost and memory requirement can be reduced. With Coulomb gauge condition, magnetic vector potential is uniquely determined. Numerical simulation was carried out on a square bore railgun by the finite ele?ment and the backward difference method, to obtain the distribution of current densities and the pro?files of current and armature velocity.

Optimal Guaranteed Cost Control Algorithm for Automatic Chain Shell Magazine

HOU Bao-lin, MA Jian-wei

2009, 30(9):  1164-1169.  doi:10.3969/j.issn.1000-1093.2009.09.003

Asbtract ( )   PDF (5325KB) ( )  

References | Related Articles | Metrics

The automatic chain shell magazine is primary subassembly of an automatic ammunition loading system of a certain big-caliber self-propelled howitzer. Due to the number change of shells in the shell magazine during firing, the positioning control problem of the shell magazine is a kind, of con?trol one of uncertain systems with parameter uncertainty. "In order to realize accurate control of the shell position, one kind of optimal guaranteed cost control algorithm based on the linear matrix in?equality (LMI) theory was put forward. First, rigid body dynamic equations of the shell magazine was built，and thoes for four special load situations were linearized. Then, according to the basic theory of the guaranteed cost control algorithm, the linearized equations of the shell magazine were expressed as the standard forms of linear uncertain systems. I he optimal guarantted cost control law for position control of the shell magazine was obtained by the LMI toolbox of MATLAB package, by which the controlled dynamic simulation of the shell magazine was carried out. The simulated results indicate that the control algorithm has high control precision.

Application of Layered Coding Genetic Algorithm to Modularized Design of Small Arms

LOU Li, XU Cheng, ZHANG Fei-meng

2009, 30(9):  1170-1176.  doi:10.3969/j.issn.1000-1093.2009.09.004

Asbtract ( )   PDF (6842KB) ( )  

References | Related Articles | Metrics

Based on the improved simple genetic algorithm(SGA), a layered coding method was pre?sented to describe the hierarchy of small arms and prevent local optimization with binary coding. Tak?ing aim at a small amount of population individualities and strong properties in modularized design of small arms, the searching capability of optimal solution was further improved by the roulette wheel se?lection, the entist model and the steady state reproduction without duplicate strategy, based on modu?larized design. Project testing was given to depict the effort. The results of one prototype system for the automatic mechanism scheme design demonstrate the effectiveness of the method proposed.

Numerical Analysis of Damage of the Concrete Target Plate Under Dynamic Loading

ZHANG Feng-guo

2009, 30(9):  1177-1180.  doi:10.3969/j.issn.1000-1093.2009.09.005

Asbtract ( )   PDF (4733KB) ( )  

References | Related Articles | Metrics

The computational constitutive model of HJC for concrete was improved further, and a ten?sile damage model of the concrete target plate was presented. Damage of the plate was simulated by above models based on the improved LTZ-2D code. The computed results show that penetration pro?cess is dominated by the plate compressive strength, final damaged state of the plate is significantly in?fluenced by tensile strength and mesomechanical characteristic has influence on damage of the plate. The proposed models are suitable for analyzing penetrating process of the projectile and damage of the plate.

Experimental Investigation into Coefficients of Concrete Targets to Prevent Perforation

GONG Zi-ming, FANG Qin, ZHANG Ya-dong, XIANG Heng-bo, ZHANG Yu-ning

2009, 30(9):  1181-1186.  doi:10.3969/j.issn.1000-1093.2009.09.006

Asbtract ( )   PDF (6081KB) ( )  

References | Related Articles | Metrics

The coefficients of the reinforced, the steel fibre and the steel fibre reinforced concrete tar?gets to prevent perforation (Kpp) were determined by combining the ballistic penetration experiments with the numerical calculation based on the six group targets prepared in different types, to determine thicknesses of the targets to prevent perforation (H) ; the influences of the projectile penetration depth (hp) and the support conditions in back of the targets on Kpp were analyzed quantitatively. The inves?tigated results show that for the targets with the same material and support condition in the back, Kpp decreases with the increasing of hp/d (caliber of the projectiles), and the steel plate on the back of the targets has little effect on H (less than 5% ) whereas the backfill soil on the back of the targets has ob?vious effect on H ( close to 20 % ).

Numerical Simulation and Analysis of Shock Initiation of Shielded Explosive Impacted by Fragments

CHEN Wei-dong, ZHANG Zhong, LIU Jia-Iiang

2009, 30(9):  1187-1191.  doi:10.3969/j.issn.1000-1093.2009.09.007

Asbtract ( )   PDF (4881KB) ( )  

References | Related Articles | Metrics

The numerical simulation of explosive covered with a metal plate of different thicknesses was studied at impacted respectively by iron, cooper and tungsten fragments; the data validity was proved by the existing experimented result; the initiation process was analyzed. By means of the up-down method, the critical detonating velocities were gained. Characteristic parameters n, k of critical energy criterion were gained by the least-square method. The critical detonating velocities were calculated through critical energy criterion, which are consistent with those of the numerical simulation. Theo?retical criterion is good for describing ignition characteristics. It can provide a reference for experiment and reliability studies in the future.

Vector Modelling and Simulation of the Unmanned Underwater Vehicle Hung with Torpedoes Externally

ZHOU Jie, WANG Shu-zong

2009, 30(9):  1192-1197.  doi:10.3969/j.issn.1000-1093.2009.09.008

Asbtract ( )   PDF (5599KB) ( )  

References | Related Articles | Metrics

In order to model the unmanned underwater vehicle (UUV j hung with torpedoes external?ly, the optimal location of external torpedoes was determined based on the calculations of the stability and the hydrodynamic parameters. The 6 DOF vector motion model of the UUV was established by the classical momentum and moment of momentum principle; hydrodynamic forces and moments ex?erted on the UUV and torpedo’s reaction forces and moments exerted on it were analyzed emphatical?ly; the simulation was performed by the model.

Influence of Fluorides on Combustion Characteristics of Mg/NaNO3 Fuel-rich Propellants

ZOU Mei-shuai, GUO Xiao-yan, ZHU Li-xun,YANG Rong-jie

2009, 30(9):  1198-1201.  doi:10.3969/j.issn.1000-1093.2009.09.009

Asbtract ( )   PDF (4498KB) ( )  

References | Related Articles | Metrics

Several kinds of fluorides were mixed into Mg/NaNO3 fuel-rich propellants by the different experimental methods for improving combustion and ignition performances, decreasing agglomeration of the metal. Burning rates of the propellants were measured. Solid combustion products of tne Mg/ NaNO3 composites mixed by fluorides were collected and analyzed by SEM and XPS. And the particle size distributions of solid combustion products were compared among the different formulations; and the effect action mechanisms of the different fluorides were analyzed. The experimented results show that burning rate of the propellants were decreased, the particle size of solid combustion products were changed after mixing fluorides into the Mg/NaNO3 compositions at a rate of 5% in excess of 100 %, and the formation of the magnesium fluoride may improve the agglomeration of the combustion prod?ucts.

An Engineering Calculation Method on the Bubble Pulse Period of Underwater Explosion

ZHOU Lin, XIE Zhong-yuan, CHEN Yong

2009, 30(9):  1202-1205.  doi:10.3969/j.issn.1000-1093.2009.09.010

Asbtract ( )   PDF (3818KB) ( )  

References | Related Articles | Metrics

Based on the experiment research of former scientists, an engineering calculation method on the bubble pulse period of underwater explosion was established by introaucing the correction factors of cylindrical and spherical charge forms into the relationship between explosion heat and bubble pulse pe?riod was revealed, and the exact calculation was realized by the method at the different explosives and charge forms. The method was verified by an experiment. The error of results between the experi?mented and the calculated is smaller than 5 % . The method provides important science basis for design?ing formulation and evaluating performance of underwater explosive.

A Novel Maximum Likelihood Channel Estimation for OFDM Systems

ZHANG Jian-kang，CHEN En-qing, MU Xiao-min,QI Lin

2009, 30(9):  1206-1210.  doi:10.3969/j.issn.1000-1093.2009.09.011

Asbtract ( )   PDF (4836KB) ( )  

References | Related Articles | Metrics

To acquire a better performance, the receiver in orthogonal frequency division multiplexing (OFDM) systems must estimate the channel state information. Maximum likelihood (ML) channel estimation for OFDM systems needs to know the effective length of channel impulse response for achieving optimum performance. Existing ML channel estimation schemes do not offer an available scheme to track the variation in effective length of channel impulse response. Based on the analysis that the ML channel estimator performance depends on the assumed effective length of channel impulse re?sponse, a modified ML channel estimator which combines the ML estimation with a policy of line search was proposed to improve the precision of the ML channel estimator. The simulated results un-der the multi-path Rayleigh channel show that the improved algorithm in this paper can track effective length of channel impulse response effectively and improve performance of the ML channel estimator.

An Adaptive Multi-threshold Selection Method Based on Index of Fuzziness

DING Yan, JIN Wei-qi, LIU Wei

2009, 30(9):  1211-1216.  doi:10.3969/j.issn.1000-1093.2009.09.012

Asbtract ( )   PDF (5813KB) ( )  

References | Related Articles | Metrics

To solve the problems of automatically getting the window size and searching zone for tradi?tional segmentation methods，an adaptive multi-threshold selection method based on index of fuzziness was proposed. By utilizing the statistic characteristic of the gray disturomg and the mstogram peak in?formation, the window width of predetermined subjection function and the threshold searching zone were determined automatically. It is useful for expanding the applicable range of threshold segmenta?tion based on index of fuzziness. The experimented results show that the gooa segmented results can be achieved by the method for the image which histogram presents multi-peak distribution.

Research on Ventilated Cavity Shapes in a Longitudinal Gravity Force Field

WEI Ying-jie, MIN Jing-xin, WANG Cong,CAO Wei, ZOU Zhen-zhu

2009, 30(9):  1217-1222.  doi:10.3969/j.issn.1000-1093.2009.09.013

Asbtract ( )   PDF (5902KB) ( )  

References | Related Articles | Metrics

The ventilated cavity flow in a static pressure gradient field of gravity force was simulated based on continuous equation, momentum equation, energetic equation, state equation and standard k- ε equation. By defining the temperature of inflow boundary as the function of time, the effect of sea longitudinal temperature in gravity force field on cavity shapes was also studied. Furthermore, research on ventilated cavity at small Froude numbers was carried out and clear cavity shape and inner structure were obtained. At the same time, rule of cavity length and maximal cavity diameter varying with cavi?ty number and Froude number was achieved under the condition of ventilated cavity with same temper?ature. The simulated results are consistent with the experienced and the experimented, wmch proves that this method can implement effectively simulation calculation of cavity shapes in a longitudinal gravity force field.

Microstructure Characterization of Twinning Under Impact Loading for AZ31B Magnesium Alloys

YANG Yong-biao, WANG Fu-chi, TAN Cheng-wen,CAI Hong-nian

2009, 30(9):  1223-1226.  doi:10.3969/j.issn.1000-1093.2009.09.014

Asbtract ( )   PDF (4552KB) ( )  

References | Related Articles | Metrics

Dynamic mechanical properties of AZ31B sheet were carried out in compression along rolling direction using split Hopkinson bar (SHPB) at the strain rate of 1200 s-1 ? Post-mortem observations were conducted using optical microscope and transmission electron microscope. The results show that both {10?1}/く10?2 > and {1?02}/< 10?1> twinning are the plastic deformation mechanisms at the strain of 0.003，which is different from the {10?2}/< 10?1 > twinning deformation mechanism under quasi-static loading condition. The evolution of microstructure inside twinning consists of parallel basal stacking faults, parallel dislocation arrays of different orientations to twin boundary and disloca?tion cells.

Preparation and Characterization of Near Infrared Absorbing Material Containing Dithiolene MetalComplexes Substituted by Alkoxyphenyl

ZHOU Fen-guo, ZHOU Tao, HE Xing-quan,LIU Da-jun, DUAN Qian

2009, 30(9):  1227-1231.  doi:10.3969/j.issn.1000-1093.2009.09.015

Asbtract ( )   PDF (5061KB) ( )  

References | Related Articles | Metrics

Three kinds of dithiolene metal complexes substituted by ethoxyphenyl, butoxyphenyl, hex- adecyloxyphenyl were synthesized and their structures were characterized by means of Infrared Spec?trum and ultraviolet-visible-near-infrared spectrum. Ultraviolet-visible-near-infrared spectrum testings of three compounds show that maximum absorption wavelengths in near infrared range are 927，929 and 932 nm with higher extinction coefficient respectively. Three kinds of near infrared absorbing PM- MA material containing the above-mentioned dithiolene metal complexes were prepared, of which opti?cal densities in the range of 900 ?I 000 nm are higher than 3.7 and the average transmittances in visi?ble range are higher 30 % . They are good near infrared absorbing materials.

Fuzzy Multifactorial Evaluation Model of Torpedo Operational Effectiveness Based on BP NeuralNetwork and Its Simulation

JIA Yue, ZHAO Xue-tao, LIN Xian-jie, CUI Shao-bo

2009, 30(9):  1232-1235.  doi:10.3969/j.issn.1000-1093.2009.09.016

Asbtract ( )   PDF (4203KB) ( )  

References | Related Articles | Metrics

The index system of evaluating torpedo operational effectiveness (TOE) was brought for?ward and the subordinate function of each index was given. The fuzzy multifactorial evaluation model of TOE was presented based on BP neural networks. The method can conquer the limition of subjec?tive factors and repeat the knowledge, experience and thought of experts. The simulated result shows effectiveness and feasibility of the model.

Identifying of the Bent Lane Based on Ant Colony Algorithm

MA Lei, WU Bo tao, LI Hao

2009, 30(9):  1236-1241.  doi:10.3969/j.issn.1000-1093.2009.09.017

Asbtract ( )   PDF (6696KB) ( )  

References | Related Articles | Metrics

Lane identifying is one of the key steps of the navigation technology in intelligent vehicle. Lane edge was simulated with parabola model, so the descriptions of the linear lane and the bent lane are unified. The lane edge was identified by an ant colony algorithm in which the search is converged in the better path as soon as possible by the positive feed back of hormone and the paraooia parameters are determined. The simulated results show that the veracity and the real-time meet the actual need.

A Bimorph Piezoelectric Ceramic Microgripper Integrating Micro force Detecting and Feedback

YE Xin, ZHANG Zhi-jing, SUN Yuan,WANG Qiang

2009, 30(9):  1242-1247.  doi:10.3969/j.issn.1000-1093.2009.09.018

Asbtract ( )   PDF (7614KB) ( )  

References | Related Articles | Metrics

The microgripper is widely used in microassembly, biology and medical applications. Con?sidering that the gripping and assembling micro structural parts and systems in complex weapon pro?duction depends on the experience of staff, it is necessary to discuss the issue in detail. Taking a bi- morph piezoelectric ceramic microgripper for instance, aiming at complex 3D micro structure and sys?tem, a bimorph piezoelectric ceramic microgripping technology integrating micro-force detecting and feedback was proposed，and corresponding microgripper was developed; the theory of micro-force de?tecting and feedback was discussed m detail, and the micro-force detecting and feedback circuit based on semiconductor-strain was established. The function was realized by experiments, which provides the conditions for micro-force measurement during the clamping, displacing and assembling process.

Modeling of Temperature Distribution Characteristics in Proton Exchange Membrane Fuel Cell withInterdigitated Flow Field

JIAN Qi-fei, WANG Dan, WEI Rui

2009, 30(9):  1248-1252.  doi:10.3969/j.issn.1000-1093.2009.09.019

Asbtract ( )   PDF (4754KB) ( )  

References | Related Articles | Metrics

Temperature distribution of the proton exchange membrane fuel cell (PEMFC) takes a im?portant influence on the cells performance especially on current density, and the interdigitated flow field helps to enhance current density. The temperature distribution of PEMFC with interdigitated flow field was investigated, by simulation method at traverse direction, anode catalysis layer, mem?brane center and cathode catalysis layer, to obtain the rule of temperature distribution. The influences of current density variation on flow field temperature at the voltages of 0.4, 0.6, 0.8 V and the tem?perature differences of membrane at inlet and outlet channels, shoulders were investigated to obtain temperature distribution rules of membrane at the different voltages.

Research on Architecture of Networked Air Defense Fire Control System

CHEN Chen, CHEN Jie, ZHANG Juan,WANG Gao-peng

2009, 30(9):  1253-1258.  doi:10.3969/j.issn.1000-1093.2009.09.020

Asbtract ( )   PDF (7645KB) ( )  

References | Related Articles | Metrics

Renovation of the air defense warfare modality results in development of networked fire con?trol system. Based on networked air defense warfare, research on architecture of networked air deiense fire control system and some correlative problems were carried on. Conception of networked air defense fire control system was given, while its components and functions were explained. A layered distribut?ed architecture was proposed ana characteristics of the architecture were analyzed. A data transmission scheme transmitting a packet of predicted data was established. According to changes of tasks and sys-tem performance, architecture reconfiguration methods were presented. Simulations were designed based on the software platform and the results were given. The research lays the foundation for realiz?ing networked air befense fire control system.

Research Notes

Experiment Study on Influence of Engine Cylinder Pressure Decrease on Equipment Main Maneuver Performances

AN Gang, WANG Kai，WANG Chuan-fei

2009, 30(9):  1259-1263.  doi:10.3969/j.issn.1000-1093.2009.09.021

Asbtract ( )   PDF (4686KB) ( )  

References | Related Articles | Metrics

Influence of engine cylinder pressure decrease on equipment maneuver was investigated by the real vehicle test from the angle of maneuver performance of. mechanized equipment. The investigat-ed results show that engine cylinder pressure dropping has great influence on the equipment perfor-mances of accelerating ability, the maximum stable velocity of each gear, fuel consumption and driving efficiency. The investigated results have direct instructive significance for operation and maintenance support of equipments.

Study on the Scanning Laser Active Imaging Guided Technology and Its Navigation Law

FAN Bao-hu, ZHAO Chang-ming, JI Rong-yi

2009, 30(9):  1264-1267.  doi:10.3969/j.issn.1000-1093.2009.09.022

Asbtract ( )   PDF (4231KB) ( )  

References | Related Articles | Metrics

A small, cheap and compact scannerless laser active imaging guided technology was proposed which can acquire the 2-D intensive imaging of targets on the ground ana the relative distance between missiles and targets timely. Based on optimal control theory and aviation mechanics, the optimal guid?ed law was deduced from taking the relative velocity into account, and the calculating methods of time- to-go were sented. The results of numeric simulation indicate that optimal guidance law has the smaller controlled energy and the shorter miss distance compared with classical proportional navigation.

Spectrophotometric Determination of Silicon in Environmental Water Sample with Silicomolybdate Blue

YU Hui, ZHAI Qing-zhou, YANG Hui

2009, 30(9):  1268-1270.  doi:10.3969/j.issn.1000-1093.2009.09.023

Asbtract ( )   PDF (2948KB) ( )  

References | Related Articles | Metrics

Silicon (IV) reacts with ammonium molybdate to form silicomolybdate yellow at hydrochlo?ric acid concentration of 0.050 mol· L-1. Silicomolybdate yellow is reduced by ascorbic acid and forms silicomolybdate blue at hydrochloric acid concentration of 1.48 mol· L -1. The maximum absorption of the complex exhibits at 346 nm and the molar absorptivity is ε346 nm = 4.5 X 104 L ? mol-1 ? cm-1. Beer，s law is obeyed over the range of 0.1?2.8 μg? mL-1 of silicon (IV) . The effect of thirty-six common co-existing substances on the determined results of silicon (IV) was observed. The method was successfully used in the determination of silicon in environmental water sample with satisfactory results.

Equipment Maintenance Colored Petri Net Model for Unscheduled Maintenance Downtime Analysis

QU Chang-zheng, YU Yong-Ii, HAO Jian-ping,ZHANG Liu

2009, 30(9):  1271-1275.  doi:10.3969/j.issn.1000-1093.2009.09.024

Asbtract ( )   PDF (4953KB) ( )  

References | Related Articles | Metrics

Based on the analysis of equipment unscheduled maintenance process, the elements of un?scheduled maintenance downtime and its influence factors on the downtime were analyzed. A multi?type tasks concurrent maintenance model was constructed based on colored Petri net, wmch reflects the maintenance resource dynamic combination and dynamic variation of the server number.Combined with task generation model, the equipment unscheduled maintenance downtime was analyzed. At last, an example was studied.

A Recursive Design Method for the Stabilization Controller of a Kind of Nonholonomic System

LI Sheng, HU Wei-Ii

2009, 30(9):  1276-1280.  doi:10.3969/j.issn.1000-1093.2009.09.025

Asbtract ( )   PDF (3874KB) ( )  

References | Related Articles | Metrics

Taking aim at a kind of nonholonomic system that can be transformed into chained form sys?tem, a recursive design method of a stabilization controller was proposed. The stabilization controller of the high dimentional nonholonomic chained system was designed by the method starting from that of the low dimentional nonholonomic chained system. And it was proved that the stabilization controller through the proposed method could guarantee all the states of n - dimensional system exponentially con?verge from the initial state which satisfies x∈Rn ,Xl,n(O)≠O to the origin. The simulated results show that the controller designed by the method is effective on the kind of nonholonomic system.