Table of Content

25 September 2008, Volume 19 Issue 18

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Effect of Dispersoids Al2O3 on Mechanical 
Properties and Microstructure of WC Matrix Composite

Yang Fazhan;Zhao Jun;Ai Xing;Zhou Yonghui

2008, 19(18):  0-2146. 

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Aided at improving the hardness and bending strength of WC matrix composites,

Al₂O₃ dispersoids particles were incorporated into the composite and a new tool material WC-ZrO₂ was prepared by hot-press sintering.Meanwhile,certain amount of VC was added to the composite to suppress the grain growth to achieve great relative density.The hardness, bending strength and fracture toughness of the composite were tested.The effect of

Al₂O₃ dispersoids content on mechanical properties and microstructure of WC-ZrO₂composite materials were analyzed.Results show that it is great significance for the incorporation of

Al₂O₃
dispersoids to improve the mechanical properties and microstructure.

Study on Laser Welding System and Technology for 
Gas Generator of Automobile Safety Airbag

Qin Yingxiong;Tang Xiahui;Liu Juan;Peng Hao;Deng Qiansong;Zhong Rutao;Li Zhengjia

2008, 19(18):  0-2240. 

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In order to develop high strength and high airproof gas generator of automobile safety airbag,

an new type transverse flow CO₂ laser and welding system were prepared,

whose mode was TEM₀₀+TEM₀₁ and whose most power was 3000W.Three-directional beam delivery welding system improves laser imposing time from 40% of one-directional beam delivery welding system to 90.9%.The laser welding technology of stainless steel gas generator body was investigated.The results show that the airproof strength of stainless steel gas generator body is

72.5~75MPa, the crazing position locates both body and welding bead,the welding strength is close to limit-strength of the material and exceeds 45MPa of requested airproof strength of gas generator body.The actual increasing temperature of the body away from welding bead 10mm does not reach 120℃, which satisfies the demand of body welding filling with gas generating products.

Geometry Arithmetic on the Tele-teaching Pose Based on Force Sensing

Liu Lijun;Dai Hongbin;Gao Hongming;Wu Lin

2008, 19(18):  0-2146. 

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The way of searching welding groove tele-teaching point based on force sensing was presented, and the geometry arithmetic of the tele-teaching pose(GATP) based on force sensing was introduced.The calculation of tele-teaching working angle and traveling angle using GATP was given.The experimental results show that the errors of working angle and traveling angle of tele-teaching based on force sensing is smaller
than that of working angle and traveling angle of the manual tele-teaching,and spread evenly.After they are filtered,the average error of tele-teaching pose angle is less than
±4° that can meet the precision of tele-teaching in remote welding.The given theoretical model and experimental data set up the groundwork to the tele-teaching pose self-adjusting.

Rational Matching Analysis of Automobile EPS Assist Motor

Chen Long;Zhao Jingbo;Cui Xiaoli; Jiang Haobin;Chen Dayu

2008, 19(18):  0-2240. 

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The structure and working principle of the assist motor of electric power steering were researched, the key technologies related to reliable operation which included the torque matching, the rotate speed matching, power matching and checking calculation,PWM drive frequency matching were designed and analyzed.A design process as the guidance of motor reliable matching was introduced and a corresponding matching performance was made based on a mini-car’s EPS assist motor.

Array Signal Based MVDR Estimation of Noise from Heavy Duty Vehicles

Zheng Sifa;Hao Peng;Luo Yugong;Lian Xiaomin

2008, 19(18):  0-2151. 

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Based on the measurement of array signals from moving noise sources, the observer equations for noise sources were built. The Capon minimum
variation distortionless response(MVDR) estimation method was obtained by optimizing the weighting factors. The identifying results is simulated and analyzed with a real running heavy duty vehicle. Comparing the results between common beam forming and MVDR method, it shows MVDR method has higher resolution and can identify the complex noise distribution of the moving heavy duty vehicle.

Experimental Study on Biodiesel Engine Emissions Using Non-thermal Plasma

Cai Yixi;Wang Pan;Wang Jun;Wang Jing;Li Xiaohua

2008, 19(18):  0-2240. 

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Based on the dielectric barrier discharge theory, the non-thermal plasma reactor was designed.The main components of the biodiesel sample were detected using gas chroma-tography-mass spectrometry.The bench test experiment was carried out,and the reduction of diesel engine harmful emissions with NTP operating on both biodiesel and No 0 diesel had been investigated. Scanning electronic microscope and X-ray energy spectrometer were used to detect the surface structure and chemical component of particular samples from the exhausts of diesel engine.Results show that the particular matter is decreased remarkably but NOx emissions change a little by NTP,the biodiesel can improve the performance of combustion and the particular matter from the oxygenated fuel has less component and small diameter.The results of elemental analysis
reveale that NTP is unaffected by exhausts impurity such as sulfur,and is one promising technology for diesel engine emissions reduction.

Investigation on the Multi-objective H₂/H_∞ Robust Control 
of the Active Suspension Based on Genetic Algorithm 

Zhao Liang ;Zhong Zhihua;Wen Guilin;Liu Guiping

2008, 19(18):  0-2240. 

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Multi-objective genetic algorithm(μMOGA) was used to deal with the conservation problem about the active suspension multi-objective control produced while solving the mixed H2/H∞ multi-objective robust control with linear matrix inequality(LMI) method.After the control gain was randomly sought by μMOGA,the H2 and H∞norm of the closed-loop system were calculated by LMI toolbox.The comparison between non-dominated solve calculated by μMOGA/LMI and the multi-objective control toolbox in MATLAB shows clearly the advantages of the μMOGA/LMI method. In the framework of μMOGA/LMI optimization,the mixed H2/H∞multi-objective robust control active suspensions were designed on a quarter-vehicle model.The comparison of the simulation results between passive and active suspension shows that ride comfort performance is clearly improved while assuring suspension deflection within bounds and convincing a firm contact of wheels to road.

Study on Calculation of Processing Parameters for Gear Camber Chamfering

Guo Wei;Xing Deqiang;Niu Zhanwen;Chen Dongliang

2008, 19(18):  0-2155. 

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The improvement was put forward to solve the problem of equipment adjusting parameter calculation algorithm for gear camber chamfering from three respects,such as accuracy,integration and practicability.The mechanism of the chamfering mathematical model was studied,and the correction equation was achieved to make the solution procedure easier,more precise.According to the geometry of measuring face and the theory of tolerance zone,the test algorithm named tolerance circle was put forward to enhance the ability of integration.Based on the definition of equipment information and the theory of graphics,the scheme of the equipment implementation was deduced,and the configuration－state matrix was set up,which was used to improve the integrity of this algorithm.

Grey Associative Analysis of Design Parameters to Leakage and Wear Performance for Finger Seal

Zhang Yanchao;Chen Guoding;Yang Meiling

2008, 19(18):  0-2161. 

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The quadratic rotary orthogonal combination design method was used to gain the test combination schemes of the design parameters for finger seal.Every scheme corresponded to a finger seal model and the models were analyzed by using FEM method through ANSYS software.The leakage and wear corresponding to different design parameters in every scheme were gained by FEM analysis.Then the influence of different design parameters on the leakage and wear were studied through grey correlative method.The results show that that of the base radius of finger with the involute shape-curve on the wear performance is more than that of the finger pad width,while the effect of the base radius on the leakage performance is less than that of the finger pad width.Compared with these two design
parameters,the thicknesses of the after finger element and the forward finger element are relatively negligible. The analysis results from grey correlative
method were validated by using FEM method.So the grey correlative method applies reference for the optimization analysis of finger seal.

Clamping Mechanism’s Position Control of IMM Based on Iterative
Learning Algorithm

Yang Yan;Wang Yunkuan;Song Yinghua

2008, 19(18):  0-2151. 

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An iterative learning algorithm was proposed to improve the clamping mechanism’s positioning precision of IMM.The algorithm is feasible to be embedded into the exiting open-loop and segment motion control method. Furthermore,a changeable update rule was introduced to accelerate the convergence speed,a forget factor and a predefined error bound were used to enhance the robustness of the algorithm. In practical applications,the algorithm ensures the smooth motion and better positioning precision of the clamping mechanism.

Research on Overhead Traveling Crane’s Rapid Design System for Mass Customization

Zhao Liping;Wang Zongyan;Qin Huibin;Dong Liang

2008, 19(18):  0-2161. 

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In order to further improve the ability of the stacking machine manufacturing enterprises to respond to market quickly,the methods of general modular design and parametric design were studied,which was guided by the thought of mass
customization.A parametric design system about the series of stacker was developed through the variant design method of the overall control the local and the product arrange technology associated with the technology of main model of products and assembly draft and database.It shortens the development cycle of new products,improves the efficiency and quality of the design,responses to the personalized market demand rapidly.

Establishment and Analysis of Error and Difference Surfaces in Spiral Bevel Gear

Chen Shuhan;Yan Hongzhi;Ming Xingzu;Zhong Jue;Xie Yaodong

2008, 19(18):  0-2151. 

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According to the structure of spiral bevel gear grinder with six axes five linkages, the error and difference surface model of spiral bevel gear was established by the multi-body system theory and the gear meshing theory, considering the geometric and thermal error. The theoretical and erroneous surfaces and its difference surfaces of a spiral bevel gear were simulated when grinding wheel spindle moves along X, Y-axis and rotates circling C axis. The results show that the motion error of grinding wheel circling C-axis rotation has a bigger influence on the surface error. This study offers a theoretic basis for improving machining precision and the error compensations of spiral bevel gear.

Nonlinear Modeling on Electro Hydraulic Servo System and SSA Control

Ni Jing;Xiang Zhanqin;Lü Fuzai 

2008, 19(18):  0-2161. 

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On the basis of electro-hydraulic servo system of pipe expanding process,the nonlinear characteristics of cylinder actuated with asymmetry valve was analyzed.Then a nonlinear model was provided to represent the actual system.A nonlinear control approach with subset stabilization approach was put forward. Simulation and actual control results show that the proposed algorithm has better response performance than that of conventional PID control.This method is a new way for engineering applications.

A Bond Graph Method of Kinetostatic Analysis for Spatial Multibody Mechanical Systems 

Wang Zhongshuang;Lu Nianli

2008, 19(18):  0-2155. 

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From the viewpoint of energy conserving,the peculiar propertiy of bond graph multiport element MTF was discussed.Based on this,the procedure of modeling spatial multibody mechanical systems by bond graphs and its dynamics principle were described.To overcome the algebraic difficulty brought by differential causality and nonlinear junction structure,the constraint forces at joints can be considered as unknown effort sources and added to the corresponding 0-junctions of the system bond graph model.The unified formulae of driving moment and constraint forces at joints were derived,they are easily generated on a computer.As a result,the static analysis for dynamics can be carried out on a computer automatically.The validity of the procedure was illustrated by a practical example.

Experimental Research and Emulation Analysis on the 
Charging Device in the Electrostatic Oiler

Wang Jiaqing;Gao Quanjie

2008, 19(18):  0-2161. 

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Electrostatic atomization principles of rust-preventative oil in the electrostatic oiler were analyzed.A new kind of charging device to reduce the atomizing voltage was developed.Experimental research and emulation analysis on the new device
were carried on.Research results indicate that the device can reduce working voltage and improve the atomizing effect and oil-coated quality.

Study on Elimination of Image Noise in the Process of Precise Curve Grinding

Hu Dejin;Wang Huai

2008, 19(18):  0-2155. 

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The thesis adopted depth of field technique,lens filter technique,and proper project technique to eliminate image noise in the process of precise curve grinding from origin,and obtain the good image quality accordingly.From the
experiments,it can make curve edge precision higher than 1μm by using these techniques,which can’t be done by pure image algorithms.Accordingly,it assures lively detecting and compensating the wear of grinding wheel,and the precision of noise decline will not change after the environment.

Dynamics Simulation Analysis of the Vibration Device of
Block Forming Machine

Wu Qingming;Jia Fei;Yang Wei 

2008, 19(18):  0-2161. 

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The virtual prototype of the vibration device of block forming machine was developed with the CATIA software. Associated to ANSYS platform,the
dynamics model of the vibration device of block forming machine was built in ADAMS,the dynamics initial value of parameters was determined by experiments,and then the model
was corrected through comparison with the actual measurements.In terms of the large vibration of block forming machine,based on the above analysis,the appropriate design variables were selected and the mathematical model was built for dynamics optimization,targeting with optimal performance of vibration isolation,then solved in ADAMS.In order to further refine and improve the entire block forming machine performance,some reasonable proposals were provided. 

Manufacture Error of Corner-filleted Flexure Hinge on the Performance 
of the Stiffness of Theoretical Modeling and Analysis 

Qin Yu;Feng Zhijing

2008, 19(18):  0-2155. 

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The manufactur errors of flexure hinge will influence the performances,so for reducing the flexible hinge on the performance of the sensitivity of manufacturing errors,the relation among design parameters of corner-filleted flexure hinge and manufacture error was founded by using multi-variable function of Taylor series expansion. Through the graph of the flexible hinge parameters and its performance, an analysis of changes of parameters on the performance of corner-filleted flexible hinge was carried out.The key manufacture parameters that affect the performances of corner-filleted flexure hinge most and rules of design are given,which can give directions of design precision flexure hinge.

Research on Production Process Planning of Iron and Steel Industries Based on CBR

Liu Xiaobing;Bo Hongguang;Ma Yue;Zhang Jinglei

2008, 19(18):  0-2161. 

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For the complexities of process planning,the difficulties in representing process design knowledge and the trouble to retrieval cases in huge process case
bases,a novel process planning scheme based on staged & hierarchical case-based reasoning(SH-CBR) system was put forward after analyzing the hierarchical and staged characteristics of process planning in iron and steel industries.Retrieving range was cut
shorter by the process planning problems being decomposed,and cases reusing was achieved by the disassembled design of case base. Process case retrieval technique based on case retrieval nets,process planning approach and algorithm basis of SH-CBR were discussed in iron and steel industries. The scheme was illustrated and verified by practical applications.

Research on Green Production Process Control Based on PDM

Wu Xiaozhen;Zhang Hua

2008, 19(18):  0-2165. 

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The production process was based on an improved
PDM as the information integrated platform.It used the process control theory and technology to optimize the process from a view of green manufacturing.Green production process control model based on PDM and green cell-process model were built.And a kind of solution was proposed,which was used to realize green production process for China manufacturing enterprises.The database and knowledge base of PDM were improved.The improved database management system reflects the green attribute of data and process better and offers a powerful data support for green production process control.

Research on the PBOM Transition of Textile Machinery

Han Dan;Zhang Heming

2008, 19(18):  0-2161. 

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The paper discussed in detail the BOM(bill of material) transition process of textile machinery products from design to process and integrally validated the
BOM transition process combining the PLM project of Jingwei textile machinery Co.,
Ltd..The research result has universal meaning of guide undoubtedly．

Elastohydrodynamics Lubrication Analysis of Misaligned Journal Bearing Considering Surface Roughness

Sun Jun;Wang Zhenhua;Gui Changlin; Liu Jianglin

2008, 19(18):  0-2165. 

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Average Reynolds equation was used to analyze bearing lubrication.The surface deformation of bearing was calculated by deformation-matrix method.The results show that the oil viscosity-pressure relationship has large effect on the lubrication characteristics of misaligned bearing, especially under condition of great misalignment angle.The surface roughness affects lubrication characteristics of misaligned bearing when eccentricity ratio and angle of journal misalignment are all large and not considering surface deformation of bearing.The directional parameter of surface has obvious effect on lubrication of misaligned bearing when ratio of least film thickness to surface
roughness is small.The surface roughness and directional parameter of surface have little effect on lubrication of misaligned bearing when considering deformation of bearing surface.Although having little effect on lubrication of aligned bearing, the deformation of bearing surface has remarkable effect on lubrication of misaligned bearing.The larger the eccentricity ratio,the greater the effect of the deformation of bearing surface on lubrication of
misaligned bearing.

Static Decoupled Contour Control and 
Pitch Error Compensation of Semi-closed-loop Three-axis CNC Machine Tool 

Zhang Jing;Li Tiecai;Wang Lisong,

2008, 19(18):  0-2161. 

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To improve the machining accuracy of a semi-closed-loop three-axis CNC machine tool,the single servo axis pitch error compensation method was presented at first.Then on the basis of constructing the semi-closed-loop three-axis machine tool decoupled contour system model,the static decoupled contour controller was studied,and the pitch error compensation method on the decoupled contour system was presented.Experiment shows that the arithmetic can fulfill the decoupled control in the contour tangent normal and bi-normal direction effectively.When the pitch error compensation method is applied on the proposed system,the max roundness error is reduced from 55μm to 12μm. 

Research on Rotor Dynamics with Sudden Change Damping 

Wang Zongyong;Gong Bin;Wen Bangchun

2008, 19(18):  0-2165. 

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Dynamics model and equation of Jeffcott rotor system with sudden change damping were established based on rotor dynamics.Vibration expression of rotor system with sudden change damping was obtained through analytical method. Relationship between the steady-state amplitudes fore and after damping suddenly changed was analyzed,and the influence of sudden change damping on maximal axis displacement
was also studied.Transient time after damping suddenly changed was defined and rubbing parameters region was determined.The conclusion indicates that sudden change damping can cause
the magnification of rotor amplitude during the transient motion stage;flex rotor system with sudden increased damping has greater possibility of rubbing;transient time is related with inherent damp,operating frequency,and axis azimuth when damping suddenly changed;rubbing parameter region will increase with mass eccentricity and sudden decreased damping magnitude enhancing.

Meshing Performance of Modified Face Gear Drive with Helical Pinion in the Profile Direction

Shen Yunbo;Fang Zongde;Zhao Ning;Guo Hui

2008, 19(18):  0-2161. 

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The meshing of face gear drive with helical pinion was investigated.A new version of face gear drive geometry was proposed as envelopes of two parabolic racks of the pinion and shaper in the profile.The results show that the meshing
performance of a modified face gear drive are improved evidently.The contact path on the flanks of tooth are distributed in the longitudinal direction, which can avoid the edge of contact.The contact path offsets to the tip and toe of face gear tooth due to it is sensitive to the alignment error especially the error of axis shaft error in the misalignment.

Development of Micro Milling Machine and Analysis of 
the Mechanics Characteristics of Micro Milling Cutter

Cao Ziyang[KG]He Ning;Li Liang

2008, 19(18):  0-2165. 

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A 3-axis micro-milling machine was constructed,which was composed of linear
motor,air high-speed static-pressure electro-spindle and motion-control card DMC-1842.And the numerical control system was developed, which can edit and execute G-code.
Furthermore,the mechanics characteristics of micro milling cutter was analyzed using FEM.By modal analysis of micro milling cutter,the inherent frequency and modal of vibration was studied,and the effect of the tool’s extended length on vibration characteristics of tool in cutting was also researched.The stress and distortion characteristics of the micro milling cutter was discussed through statics analysis.

Investigation of Ultrasonic Vibration Electrical Discharge Milling in Gas

Su Shupeng;Zhang Qinhe;Zhang Jianhua; Gao Qing

2008, 19(18):  0-2161. 

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The principles of ultrasonic vibration electrical discharge
milling(UED-Milling) in gas were introduced. According to the machining
features of UED-Milling in gas,twice-layered slicing strategy and tool path planning algorithm with the couple of direction-parallel machining path and contour machining path were given.Experimental results show that higher efficiency can be accomplished and bigger layer thickness and bigger servo feed rate
can be chosen in UED-Milling in gas with the aid of ultrasonic vibration.3D sample with trapezoid cavity was verified the feasibility of the approach. 

Study on Thermal Elasto-plastic Contact Problems with Temperature-dependent Properties 

Tong Ruiting;Liu Geng;Liu Tianxiang

2008, 19(18):  0-2165. 

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A thermal elasto-plastic contact model which can take into account the effects of temperature-dependent yield strength was developed by using finite element method.The influences of the steady-state frictional heat on the contact performance of surface asperities and subsurface stress distribution in contact bodies were investigated.The maximum contact pressure will be overestimated and the contact areas will be underestimated if the effects of temperature-dependent yield strength were ignored. Furthermore,the
thermal effects on the contact pressure and average gap of real rough surface with different frictional heat inputs under the thermal elasto-plastic contact
conditions were studied.The effects of temperature-dependent thermal expansion coefficient on stress distribution was investigated through the contact analysis of a rigid cylinder with a thermal elasto-plastic plane.The stress level of the contact body is higher relatively,and contours of the stress distribution expand to the boundary.

Effect of Electrode Tip Geometry on Electrode 
Degradation during Resistance Spot Welding Zinc Coated Sheet Steel

Dong Shijie;Zhou Norman 

2008, 19(18):  0-2161. 

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The effect of electrode tip geometry on electrode degradation during resistance spot welding zinc coated steel sheet was investigated by scanning electron microscope and energy dispersive X-ray spectrometer.The results show that domed electrode degradation mechanism is basically caused by wear due to fracture of local welding between the electrode tip surface and zinc coated sheet steel happen at electrode surface,
and alloying between electrode and zinc on coated sheet steel during resistance spot welding zinc coated sheet steel. The truncated electrode degradation mechanism is basically caused by wear and a little alloying,and by a mass of deformation on electrode tip. 