Volume 33,Issue 10,2010 Table of Contents

1 Transmission model of higher-order elliptical bevel gearing and motion simulation for interference checking

LIN Chao , HOU Yu-jie , RAN Xiao-hu , LIU Gang , QIU Hua , RUAN Xiao-yong

2010, 33(10):1-6. DOI: 10.11835/j.issn.1000-582X.2010.10.001

[Abstract](2666) [HTML](0) [PDF 5.82 M](1425)

Abstract:
Higher-order elliptical bevel gear is a typical form of the noncircular bevel gear transmission.Space spherical coordinate system of the bevel gear meshing is set up based on the meshing theory of space transmission.The varying relationship among the pitch curve,tooth profile and mesh lines are analyzed,and the equation of the gear tooth surface is developed with matrix method based on space coordinate transformation.The basic parameters of the noncircular bevel gear such as transmission ratio,modulus and the number of teeth are designed,and detailed analysis of the influence of the eccentricity on the relevant parameters is carried out as well.By using discrete numerical method and three-dimensional software,the mathematical model of the tooth profile and virtual physical model of the noncircular bevel gear are established,and then simulation on its motion and interference checking are performed.Finally,the approach for design,calculation and generation of the tooth profile is obtained and its correction has been verified by experiment.

2 Accuracy analysis for frequency estimation of amplitude ratio method

BO Lin , DONG Peng-fei , LIU Xiao-feng , XU Guan-ji

2010, 33(10):7-13. DOI: 10.11835/j.issn.1000-582X.2010.10.002

[Abstract](2344) [HTML](0) [PDF 7.08 M](2036)

Abstract:
Aiming at the spectrum leakage that exists in fast Fourier transform (FFT),several ratio frequency estimation algorithms that widely used by engineering signal processing are deeply studied.Firstly,the principles and features of these algorithms are introduced,and the influences of three parameters on frequency estimation accuracy are concretely analyzed.These parameters are signal to noise (SNR),cycles covered in record and the distance from the DFT output peak to the true frequency in bin widths.Then,related simulations are carried out to analyze and compare the performance of these frequency correction methods.The simulation results show that the frequency estimation accuracy has lower limit.When the number of the waves in the tone is small,the accuracy of these methods is poor,but can be improved observably by increasing the waves for the most methods.When the number of the waves in the tone is large,most methods have high and stable accuracy.The performance of the Rife-Jane’s method and Vetterling’s method can be improved by using Hanning-tapered data.Finally,considering specific engineering environment,some rules and principles about how to choose appropriate algorithm are provided.

3 Dynamic characteristic analysis and optimization of high power-density steering gear

ZHOU Yi , ZHU Hui-yi , CHENG Wen-sheng , XU Shao-hu

2010, 33(10):14-18. DOI: 10.11835/j.issn.1000-582X.2010.10.003

[Abstract](2152) [HTML](0) [PDF 4.13 M](1374)

Abstract:
Steering gear is an important device on a ship,whose performance quality affects ship greatly.Aiming at high power-density steering gear which is composed of electro-hydraulic system and ball rotary-oscillating actuator,a mathematics model of the steering gear system is deduced.The system optimization design is carried out using optimization theory.Dynamic simulations of the pre and post optimized systems are made by MATLAB software to analyze dynamic characteristics.The analysis results show that the optimized steering gear can meet practical needs.

4 Vehicle stability control system design using optimal allocation of yaw moment

LUO Hong , ZHANG Li-shuang , LAI Fei , CHEN Xing

2010, 33(10):19-24. DOI: 10.11835/j.issn.1000-582X.2010.10.004

[Abstract](2792) [HTML](0) [PDF 4.93 M](1852)

Abstract:
In order to improve vehicle handling stability,a control system using optimal allocation of yaw moment was designed.The first layer is a linear quadratic regulator (LQR) controller,which optimizes a desired yaw moment to work on the vehicle and calculates reference wheel slip for the target wheel.The second layer of the control system is a PID controller which can track the reference wheel slip rate,and then apply braking torque on the target wheel to make the vehicle stable.Simulations are carried out by using an 8-dof nonlinear vehicle model under different conditions.The simulation results indicate that the designed control system can effectively improve vehicle handling stability.

5 Application of state feedback and observer inmulti-axle vehicle steering system

WANG Huan , GAO Xiu-hua , ZHANG Xiao-jiang , HUANG Da-wei , CHEN Shu-qing

2010, 33(10):25-31. DOI: 10.11835/j.issn.1000-582X.2010.10.005

[Abstract](2146) [HTML](0) [PDF 5.71 M](1362)

Abstract:
A 3-degrees of freedom multi-axle vehicle dynamic model is established.Taking account of the practical difficulties for measuring the sideslip,rolling angles and rolling angle speed,a Luenberger observer is designed,and the simulation and analysis of the Luenberger observer are performed.The results show that the Luenberger observer has excellent characteristics in the considered speed range in tracking path.Then,a state feedback controller is designed on the basis of the Luenberger observer,and simulation of a multi-axle vehicle is also carried out.The results show that the performances of a multi-axle vehicle with the proposed control strategy is better than a multi-axle vehicle with front wheel steering strategy,and its control system has fine dynamic characteristic and strong robustness,so multi-axle vehicle with the proposed control strategy can improve vehicle handling stability and security.

6 Brittle material removal mechanism of ultrasonic vibrationassisted grinding

ZHANG Hong-li , ZHANG Jian-hua

2010, 33(10):32-36. DOI: 10.11835/j.issn.1000-582X.2010.10.006

[Abstract](2179) [HTML](0) [PDF 6.39 M](1773)

Abstract:
To remove the brittle material in ductile state can help to improve the machined surface quality.Experiments of material removal mechanism for NdFeB are conducted by using tangential ultrasonic vibration assisted grinding,axial ultrasonic vibration assisted grinding and normal ultrasonic vibration assisted grinding.Based on the critical condition of brittle-ductile transition,the effects of different ultrasonic vibration modes on material removal mechanism are analyzed.Results indicate that the material is mainly removed in the form of plastic shear in axial ultrasonic vibration assisted grinding.The material is mainly removed in the form of transgranular fracture,plastic shear and little intergranular fracture in tangential ultrasonic vibration assisted grinding.While in normal ultrasonic vibration assisted grinding,the material is mainly removed in the form of fracture crash and the cracks remain in the machined surface.So axial ultrasonic vibration assisted grinding is the best machining method to realize the ductile grinding on brittle materials.

7 Effect of deformation conditions on twinning of AZ31 magnesium alloy during compression test

LIU Tian-mo , YUAN Han-qi , PENG Tian-cheng , LIU Jian-zhong

2010, 33(10):37-41. DOI: 10.11835/j.issn.1000-582X.2010.10.007

[Abstract](2057) [HTML](0) [PDF 9.33 M](1387)

Abstract:
Deformation twinning of homogenizing magnesium alloy AZ31 is respectively investigated by compression at room temperature with different deformation degrees from 5% to 15% and different deformation rates from 0.5 to 4mm/min.The results show that thick twins exit in a few amount of crystals at the beginning of the deformation.The thin-long twins and the thick twins appear at the end of the deformation,and they can be observed in almost all crystals.With increasing compressing rates,the yield strength,compression resistance fracture strength and density of twins increased,and twins become thin.

8 Thermogravimetric study on the pyrolysis performance and its impactfactors of several kinds of typical industrial sludge

YANG Lin , RAN Jing-yu

2010, 33(10):42-49. DOI: 10.11835/j.issn.1000-582X.2010.10.008

[Abstract](2280) [HTML](0) [PDF 12.45 M](2488)

Abstract:
Thermogravimetric analysis is used to determine the pyrolysis performance of three types of industrial sludge and their mixed samples at different pyrolysis temperature,sample diameter,heating rate,pyrolysis pressure and adding different metal element compounds.At the same time,the pyrolysis mechanism equations and pyrolysis reaction parameters are obtained.The results indicate that the pyrolysis temperature,sample diameter,heating rate,pyrolysis pressure play an important role in the pyrolysis process for industrial sludge.The metals element compounds can improve the pyrolysis performance of industrial sludge.The pyrolysis reaction progression is respectively 1,1.5,and 2.0 in low,medium and high temperature segment for three types of industrial sludge,the pyrolysis character of mixed sludge isn't obviously changed.The pyrolysis characters of the industrial sludge are alike as the coal residue,the activation energy and the frequency factors are smaller at the initial pyrolysis process,they are increased with the increase of the pyrolysis temperature.The activation energy and the frequency factors are enhanced at the end of pyrolysis.

9 Investigation on the flow field in the connection sectionbetween two heat exchangers of a condensate gas water heater

HE Chuan , LIANG Hong-qiang , WANG Yan-jun , DUAN Zhi-qiang , WANG Dan , LONG Tian-yu

2010, 33(10):50-56. DOI: 10.11835/j.issn.1000-582X.2010.10.009

[Abstract](1883) [HTML](0) [PDF 21.54 M](1200)

Abstract:
This paper investigates a new type of condensate gas water heater,which consisted of a burner,a high temperature heater exchanger (i.e.rut exchanger) and a low temperature heater exchanger (i.e.subjoin exchanger or condensate exchanger).These components are set vertically one by one with a same rare plane.The subjoin exchanger is set at top and smaller in width than the rut exchanger and burner.A lean plane with some holes is set in the connect channel between the two exchangers aslant.As the flue gas flow crows the subjoin heater exchanger,the gas temperature will be below the dew point,and the same steam in the gas condensed into water.These blobs drip to the lean plane and are collected through the holes on the plane.The flow field of the connect channel and subjoin exchanger affected by the dip angle and holes distribution of the lean plane is investigated with CFD.The results show that there is a suitable configuration about the dip anger,hole's diameter and distribution of the lean plane.With that configuration,the flue gas can wash the tubes of the subjoin heat exchanger homogeneously in a higher velocity than the rut exchanger does.

10 GGH heat transfer enhancement and a new type heat exchangerin the desulphurization system of wet flue gas

ZHOU Jie , GAO Cuan-yun , WANG Jian , TAN Zhi-ming , LIAO Guang-ya

2010, 33(10):57-63. DOI: 10.11835/j.issn.1000-582X.2010.10.010

[Abstract](1971) [HTML](0) [PDF 6.08 M](1368)

Abstract:
This paper conducts in-tube heat transfer experiments in a three dimensional fin tube with 102 mm outer diameter.Compared with the smooth tube,the heat transfer enhancement ratio is between 1.65 and 1.7,and the pressure drop ratio is between 1.65 and 1.7.Based on the analysis of the heat transfer and tube surface temperature,a new type heat exchanger is put forward.Moreover,the design and calculation method is explored.The engineering example indicate that not only the tube surface temperature is higher than the smooth tube,but also the quantity of heat is increased by about 20% than the smooth tube.Compared with other types,the new type heat exchanger has a overall better performance.

11 Non-linear finite element analysis based on the spatial catenary cables

YAN Zhi-tao , LIU Cao-lan , LI Zheng-Liang

2010, 33(10):64-69. DOI: 10.11835/j.issn.1000-582X.2010.10.011

[Abstract](2880) [HTML](0) [PDF 5.05 M](2181)

Abstract:
According to the elastic catenary theory,this paper derives the spatial catenary cable element from the exact analytical expression,which is used for finite element analysis of the structure.It deduces the precise expression of two-node cable element tangent stiffness matrix and the tension of cable end.The equivalent node load of cable element is expressed by the total load algorithm,and the non-linear equation is solved by double Newdon-rapson method.The proposed non-linear semi-analytical finite element method based on spatial catenary cable element can take full account of the impact of non-linear geometry.The initial configuration and the internal forces on any directional spatial loads can be solved.The example shows that the calculation method is accurate and effective.

12 A simplified approach to define the yield surface of concrete-filled square steel tubes subjected to compression-bending

LIU Yang-bing , LIU Jing-bo , HAN Qiang , ZHENG Ni-na

2010, 33(10):70-75. DOI: 10.11835/j.issn.1000-582X.2010.10.012

[Abstract](4953) [HTML](0) [PDF 10.12 M](7964)

Abstract:
When the plastic hinge method is used to simulate the elasto-plastic properties of concrete-filled steel tubular structures,the plastic interactive yield surfaces of concrete-filled steel tubular column sections need to be defined.Although the fiber model approach can be well applied to the yield surface analysis,the numerical method is still complicated for the real applications.Therefore based on the experimental and theoretical researches on concrete-filled square steel tubular (CFST) members,this paper develops one method to determine the elastic element parameters.Then a simplified approach to quickly define the axial force-moment interactive plastic yield surface of concrete-filled square steel tubular columns is developed through theoretical analysis and a large number of parametric analyses.Finally,the fiber model method is adopted to verify the feasibility and validity of the proposed method.Results of the two methods are in good agreement,which indicates that the proposed method is reliable.

13 Fire-resistance performance of high-strength-steel H shaped columns under the axial compression

WANG Wei-Yong , LI Guo-Qiang , DAI Guo-Xin

2010, 33(10):76-82. DOI: 10.11835/j.issn.1000-582X.2010.10.013

[Abstract](3084) [HTML](0) [PDF 15.91 M](1249)

Abstract:
In order to investigate the fire-resistance performance of high-strength-steel column,this paper deduces the critical stress of high-strength-steel columns under the axial compression at high temperature by introducing the mechanical properties of high-strength-steel at high temperature.Moreover,coefficients of overall stability and critical temperature for high-strength-steel column under the axial compression are obtained which can provide a reference for design.The comparison of overall stability coefficient and critical temperature between high-strength-steel and normal steel is made.The results show that the overall stability coefficient and critical temperature for normal steel is not applicable for high-strength-steel,and the overall stability coefficient for high-strength-steel is smaller than that for normal steel.The paper uses the finite element analysis to validate the overall stability coefficient,and good match was found between them.

14 Program design and realization by the columnlength amending method to simulate the construction

YUAN Zheng-qiang , LIANG Jian-zhong , ZHANG Shou-yun

2010, 33(10):83-87. DOI: 10.11835/j.issn.1000-582X.2010.10.014

[Abstract](3948) [HTML](0) [PDF 14.23 M](6757)

Abstract:
This paper uses the column length amending method to realize the construction simulation,and verified the feasibility of the column length amending method and the accuracy of the program design by comparing calculation results of examples.Due to the characteristic of the column length amending method,it is convenient to consider many factor affection of concrete during the construction process.At same time,each layer can be analyzed conveniently after construction.

15 On-demand routing algorithm based on load balancing and mobility prediction in wireless mobile Ad hoc network

ZHU Bin , ZENG Xiao-ping , Liao Hong-yun , CHEN Li , WEI Geng

2010, 33(10):88-93. DOI: 10.11835/j.issn.1000-582X.2010.10.015

[Abstract](1841) [HTML](0) [PDF 1.12 M](1950)

Abstract:
The traditional routing protocol for wireless mobile ad hoc networks is unable to achieve balanced energy consumption and could not adapt to the dynamic topology changes well.A novel on-demand rooting algorithm is proposed based on load balancing and mobility prediction.The proposed rooting algorithm excludes the unstable links in routing discovery,and allows the node with more energy forward the routing request packet preferentially.In addition,it adopts the active local routing recovery strategy by predicting the link connection time,and finishes the repair work before the link being actually failure.The simulation experiments demonstrate that,comparing with the traditional AODV protocol,with slight increase of the rooting control overhead,the proposed algorithm increases the average packet delivery ratio,decreases the average end-to-end delay of the data packets,and achieves load balancing in the network and prolong the life-span of the network,which shows the proposed algorithm is highly practical.

16 Image inpainting based on nonlinear anisotropic diffusions

CHEN Jian-jun , TIAN Feng-chun , QIU Yu SONG , Jian-wen

2010, 33(10):94-97. DOI: 10.11835/j.issn.1000-582X.2010.10.016

[Abstract](1942) [HTML](0) [PDF 5.52 M](1311)

Abstract:
Following the features of curvature and gradient at image edges,an image inpainting method based on nonlinear anisotropic diffusion is proposed.The diffusion can be conducted with different directions and different intensities according to the geometric features of the inpainted images.An adaptive factor is introduced based on the curvature and gradient of the image local geometric information,which can control the diffusion direction and diffusion intensity.At the edges in images,the diffusion coefficients are large for the horizontal directions,while the diffusion coefficients are small for the vertical directions.At the smooth regions,the diffusion coefficients are the same for different directions and they are usually large.Compared with the typical total variation method,the curvature derivation diffusion method,and P-laplace constant variation method,the experimental results show that the proposed method can improve the qualities of the inpainted images

17 A novel substrate integrated waveguide broadband bandpass filter

CHEN Shi-yong , TIAN Shu-lin , MENG De , YANG Lin

2010, 33(10):98-101. DOI: 10.11835/j.issn.1000-582X.2010.10.017

[Abstract](2205) [HTML](0) [PDF 3.38 M](1603)

Abstract:
A novel broadband substrate integrated waveguide bandpass filter is presented based on the highpass characteristics of substrate integrated waveguide (SIW) and the bandstop performance of photonic band gap (PBG) structure.In order to verify it,a wideband bandpass filter with center frequency of 5.0 GHz and fractional bandwidth of 60% is designed.The electromagnetic simulation results show its good passband characteristics from 3.5 GHz to 6.5 GHz,and the maximun insertion loss is about 0.64 dB.An experimental filter prototype is fabricated with standard PCB technics and measured with the vector network analyzer.The measured results show the passband is from 3.8 GHz to 6.8 GHz,the fractional bandwidth is about 56%,and the minimal insertion loss is about 1.6 dB.The measured results are in good agreement with the simulated results.

18 Load balancing strategy and ant optimization algorithm for grids

CHEN Yi-xiong , WU Zhong-fu , ZHU Zheng-zhou

2010, 33(10):102-109. DOI: 10.11835/j.issn.1000-582X.2010.10.018

[Abstract](2281) [HTML](0) [PDF 7.57 M](1331)

Abstract:
In view of the Campus Grid construction,which is also a crucial part of ChinaGrid project,the performance decline for grid scheduling algorithms when non-dedicated nodes emerge in multi-grid environment is studied.A load balancing algorithm to optimize resource usage rate is proposed.The paper involves three parts: problem modeling,algorithm design,and experiment evaluation.The experimental results show that the proposed algorithm is effective for solving the problem of resource usage rate decline under the discussed grid circumstance.

19 Text knowledge management oriented adaptive Chinese word segmentation algorithms

FENG Yong , HE Xun , TANG Li , CHEN Xian-yong , CHEN Zhen

2010, 33(10):110-117. DOI: 10.11835/j.issn.1000-582X.2010.10.019

[Abstract](2170) [HTML](0) [PDF 6.43 M](1741)

Abstract:
To overcome the shortcomings of new word recognition and special word processing for the traditional dictionary-based matching algorithm in,text knowledge management oriented adaptive Chinese word segmentation algorithm (SACWSA) based on 2-gram statistical model is presented..At the preprocessing stage,SACWSA applies finite state machine theory,conjunction-based partition method and divide conquer strategy to partition long sentences in input text into sub-sentences,which reduces the algorithm complexity effectively.At the word segmentation stage,2-gram statistical model is employed and combined with partial probability and overall probability to partition the sub-sentences into words,which improved the recognition rate of new words and eliminated ambiguity.At the post-processing stage,the matching rules of part-of-speech are established to eliminate ambiguity of 2-gram word segmentation results further.The innovations of SACWSA include dealing with the long sentences and long terms with the idea of ’Divide and Conquer’; while combining the partial probability and overall probability to identify new words and eliminate ambiguity.Experimental results on text corpus of different fields show that SACWSA can adapt to different text knowledge management requirements in different fields accurately,efficiently and automatically.

20 Uncertain reasoning model for the rocket safety decision system

LI Ya , ZHANG Jian-xun , YANG Xin

2010, 33(10):118-122. DOI: 10.11835/j.issn.1000-582X.2010.10.020

[Abstract](1721) [HTML](0) [PDF 4.10 M](1078)

Abstract:
In view of the complexity of the measuring environment and uncertainty of the a prior knowledge for rocket aviation,a rocket safety control system based on uncertainty reasoning is proposed.The uncertain representation and processing of the knowledge in expert systems are established according to the characteristics of the parameters .Following the characteristics of the decision rules and decision procudure,the reasoning control strategy is studied and the method for conflict resolving strategy and searching strategy is proposed.Then,the uncertain matching rules and the feasibility degree delivering method are expressed,and the decision-making network and the rule-based uncertainty reseaoning model were constructed.Simulation experiments show that this system can acquire the craft launching information quickly and accurately,which greatly improves the reliability and authenticity of safety control decision for rocket aviation,and can control the rocket aviating state effectively.

21 Design and implementation of trusted network interaction pattern

PENG Shu-fen , HE Jing-sh , GAO Fenga

2010, 33(10):123-128. DOI: 10.11835/j.issn.1000-582X.2010.10.021

[Abstract](2249) [HTML](0) [PDF 4.85 M](1128)

Abstract:
In order to establish network interaction pattern based on trust,trust-based basic interaction patterns were proposed and the fuzzy production rules were designed.The basic interaction patterns were used to describe degree of truth of the interaction event trust and that of the integrated interaction pattern.Furthermore,the searching algorithm and refreshing method for the basic interaction pattern based network interaction pattern were proposed.The searching algorithm for integrated interaction pattern is based on the depth-first search algorithm for stack and heap.The active refreshing for integrated interaction pattern is based on user's requirements,while the passive refreshing for integrated interaction pattern is based on trust changes between the interacted entities and the interaction event changes.Theoretical analysis and experiment results show that the method can establish trusted integrated interaction patterns quickly and refresh degree of truth of the integrated interaction patterns.

22 Predicting the DNA splice sites with conditional random field

YANG Wang-Li , XU Shao-hua

2010, 33(10):129-132. DOI: 10.11835/j.issn.1000-582X.2010.10.022

[Abstract](1693) [HTML](0) [PDF 3.51 M](1250)

Abstract:
Predicting the DNA splice sites has become the most attractive and important issue in the field of genome information research due to its great help to find gene coding area.Current gene recognition algorithms mainly consider the global features of the coding area,instead of the specific information of the splicing sites,which are usually unable to recognize the splicing sites accurately.A new method based on the conditional random fields (CRFs) is proposed for splice sites prediction.CRFs can capture long distance dependent relationships between labels and avoid label bias.Experimental results show that CRFs is suitable for splice sites prediction and can improve performance.

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