Table of Content

26 June 2011, Volume 22 Issue 12

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Study on Vibration Control of Bladed Disk Structure Considering Circuit Mistuning

WANG Ai-Lun, LI Lin

2011, 22(12):  1387-1392. 

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A dynamic model of bladed disk structure with coupled piezoelectric network was established based on bond graph,which is an effective tool for modeling of system with multi-energy domains.The effects of circuit mistuning on vibration characteristics of bladed disk were investigated.

Then an experiment was design to validate the conclusion.The results show

that circuit mistuning will influence the dynamic characteristics of bladed disk,the effect is related to the distance between the blade and mistuned shunt circuit,the greater the distance the smaller the impact.And resistance mistuning makes the greatest effect on blade maximum amplitude, while capacitance mistuning has no effect.Additionally,the study indicates that circuit mistune does not always aggravate vibration localization in bladed disk,which may be decreased under certain circuit mistune mode. It indicates that compared to tuned piezoelectric network, an appropriate mistuned network can suppress bladed disk vibration better.

Influence of Workpiece Geometry on Numerical Calculation of Cutting Force for Stainless Steel 

TAO Song, HU Xu-Jin, WANG Hua-Lin

2011, 22(12):  1392-1396. 

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This paper is to establish a finite element model of orthogonal cutting by studying the key technology of dynamic constitutive relation of AISI-316L materials,contacts between tool and chip,chip separation,chip crack.Authors used large-scale finite element software ABAQUS to simulate the cutting process, then discussed and compared the simulation results in different geometric models.Finally it is indicated that the established finite element model is reasonable,and an optimal geometric model is obtained from experiments.

Study on Nonlinear Parametrically Exited Coupling Vibrations of Roller System on 4-H Rolling Mills

LIU Gao-Ran, SHI Pei-Meng, CHEN Gao, HOU Dong-Xiao

2011, 22(12):  1397-1401,1417. 

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A vertical nonlinear parametrically exited coupling vibration model of 4-h rolling system was established, which considered the nonlinear damping and nonlinear stiffness between working rolls and supporting rolls to rolling mill's frame,The parse approximation solution were carried out by using multiple-scale

method,under main frequency,1∶1 inner resonance,and the curve equations of amplitude-frequency were obtained. The vibration characteristics of the system under nonlinear stiffness and nonlinear damping were analyzed. With the changes of nonlinear stiffness, the amplitude appears the jumping phenomenon. It leads instability of the system. The numerical simulation indicates that the solution is validated. Local bifurcation was studied with parameter transform. It can offer some theoretic guidance on vibration mechanism and control in rolling mills.

Steel Surface Defect Recognition Based on Support Vector Machine and Image Processing

SHANG Bo, KONG Jian-Yi, WANG Xin-Dong, CHEN Li

2011, 22(12):  1402-1405. 

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Based on machine vision technology a steel plate surface defect detection was discussed.The characteristic values for six kinds of typical steel plate surface defect images were extracted and the dimensions reduced reasonably form 32 to 20.The principles and algorithm of SVM were introduced, and the method to classify the six kinds of steel plate surface defects using SVM was presented.The optimization of important parameters was obtained.The steel surface defect images have been classified

with SVM,and then compared with a BP neural network algorithm. The results show that classification of steel strip surface defects based on SVM theory is effective, fast and robust.

Study on Control Algorithm for Stone Sculpture Ground by 5-Axis Feed

CHEN Wei-Xu, ZHANG Ji-Yu

2011, 22(12):  1406-1413. 

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A control algorithm in 5-axis simultaneous feed was presented to cut and grind the stone sculpture.By slicing the sculpture in surfaces the nodal points were utilized on the curves,and the elliptic curves in sets were fitted on the sculpture. The control model for relative position between the grinding disc and sculpture was established based on the elliptic curves fitted,which was suitable for 5-axis simultaneous feed in the QSJ reconstructed bridge type stone grinding machine originated in China. The interpolation feed in space moving trace for the grinding disc was realized by using the control algorithm and the elliptic curves were enveloped on the sculpture curves. Both the simulation and the

grinding test show that the automatic grinding control can be realized for complex curve manufacturing on the stone sculpture, and featured with high accuracy, effectiveness and reproducibility.

Research on Edge Effect and Longitudinal Modification of Involute Spur Cylindrical Gear Pairs

WEI Yan-Gang

2011, 22(12):  1413-1417. 

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An accurate 3-D model of crowning modification involute gear was made by combining parameterized modeling function of Pro/E with gear engagement theory.The edge effect in meshing process of involute spur cylindrical gear pair was validated by FED.Using gear engagement theory and contact mechanics theory, longitudinal modification of gear pair was designed combining crowning technology of

roller bearings with the characteristics of gear engagement.Then it is testified by FEA that longitudinal modification can avoid the edge effect in the meshing process of involute spur cylindrical gears, so maximum stresses of gears can be reduced effectively.

Comparison between ISO and AGMA Gear Strength Rating Methods for Involute Cylindrical Gears

TUN Chang-Lin, LV Yun-Fei

2011, 22(12):  1418-1423,1465. 

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Comparative analysis of involute cylindrical gear strength rating methods used by ISO standard and AGMA standard was conducted.Gear parameters and derating factors were classified.Differences between the meaning and selection of gear parameters and derating factors,as well as their effects on gear rating results,were analyzed through calculations.The study indicates that neither of the two standards is more conservative than the other one, and the bending strength rating results of AGMA standard are more sensitive to the change of gear geometry parameters.The study also indicates that different values of parameters and derating factors cause the differences in gear rating results of the two standards.The allowable stress number,load,geometry parameters and life have the most significant effects on pitting resistance rating results; while the stress correction factor relevant to the test gears, load and geometry parameters have the most significant effect on bending strength rating results.

Remote Measurement Methods of Fluid Flow Based on Pressure Wave Transmission

YAN Wei

2011, 22(12):  1424-1426. 

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In order to achieve a remote measurement for fluid flow,research was made on theoretic models and experimental measurement methods for transmission pressure wave of the horizontal pipeline.A transmission line modeling(TLM) network modeling method was used to measure the pressure wave attenuation of the horizontal pipelines in the downstream from the flow meter,the theoretic data was also obtained by using its theoretic models.It is found that the theoretic models and experimental results are matched closely.It has shown the values of such a theoretic model and the feasibility of the remote measurement of fluid flow.

Research on Resource Matching of Complex Assembly Process under Project-based Manufacturing

XU Jian-Ping-1, 2, GUO Gang-1, LUO Yu-1, 3

2011, 22(12):  1427-1433,1488. 

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Organization and management of manufacturing process in large-scale and complex product enterprises is different from common products because of the complexity of products.Layered production planning module was established to meet the needs of project-based manufacturing, which integrated project management with MRPⅡ system. On account of the final assembly process of large-scale and complex

products a resource matching matrix based on period of time was built to evaluate the resource matching degree with production planning. At the same time, a queuing principle was applied to optimize limited resource capacity matching of multi-projects,so that the feasibility of the final assembly scheduling can be increased and the product can be completed on time according to the delivery time.

Research on Construction Process of Extended Manufacturing Alliance

AN Bei, LIAO Wen-He, GUO Yu, LIU Jiao-Jian

2011, 22(12):  1434-1440. 

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According to extended manufacturing was a new networked manufacturing model,which was oriented to armament and another complex products,a construction method of extended manufacturing alliance was proposed.The concept of networked manufacturing coupling was presented,and the construction process of extended alliance based on rising coupling and dropping coupling strategies was

proposed;The correlation of extended tasks was analyzed, and dropping coupling decomposition was realized.The correlation of extended resources was analyzed,the optimization objective of resource allocation was determined,and extended resources rising coupling allocation was realized.At last, the application of aircraft on the extended manufacturing platform was described,and feasibility and applicability of the method of the extended alliance construction were verified. 

Complex-structure Automatic Assembly System Based on Multi-agent

MIAO Xin-Gang, HONG Su, FU Ji-Wu, GUO Qian

2011, 22(12):  1440-1443. 

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Complex-structure assembly detection integrated system included automatic assembly, precision orientation, error checking, process simulation and data storage. It was made up by flexible numerical control assembly platform, industrial robot, laser tracker and laser scanner. The cooperation of all parts is the key technology. It can be seen from analyses that the technology of multi-agent is very suitable for

the assembly, so the multi-agent model is made. The whole system can be divided into

several separate agents, they can communicate by local area network, and they can negotiation by contract net protocol, so they can accomplish the assembly task reliably and effectively.

Primary Exploration of Optimization Theory and Method for Ordering Coupled Tasks

WANG Zhi-Liang, WANG Yun-Xia, LIU Yun

2011, 22(12):  1444-1449. 

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Different sequences of the coupled task sets lead to different lead time, so optimization sequence is a key for reconstructing complex product development process. As there are whole iterations stemming from activities' coupling in complex product design process, this paper first proved two theorems of ordering coupled tasks by stochastic process theory:(1)comparing with other tasks with longer task time,

the task with a shorter task time should have ahead of implementation.(2)comparing with other tasks with a smaller output probability, the task with a larger output probability should have ahead of implementation.Then,tearing algorithm for sequencing based on

time-coupling(TATC) was presented by the two theorems.This paper also verified the validity and effectiveness of TATC by simulation as to the five coupled tasks.An illustrative example was given to show TATC practical application finally.

Prediction and Analysis of Molten Steel Temperature for Refining Process

FENG Xu-Gang-1, 2, BI Ye-Tai-1, ZHANG Jia-Yan-2

2011, 22(12):  1450-1453. 

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Heat transfer and temperature variation rules of molten steel during RH-MFB refining process were developed. And a model for forecasting temperature of molten steel was established to simulate the actual process by using BP neural network and fuzzy algorithm. The forecasting results of temperature of 15 heats molten steel in 300t ladle RH-MFB refining show that temperature maximum error of molten steel at decarburization end-point of RH process is 7.2℃,a minimum 0.3℃,average error of 4.52℃ and within ±5℃ by 82.7%.Also,according to the actual situation,temperature compensation was achieved by adding aluminum or cooling materials.

A Study of Structure Modal Parameter Identification Based on Second Order Non-stationary Source Separation

LIU Xiao-Wei, LI Shun-Ming, ZHANG Yuan-Yuan

2011, 22(12):  1454-1458. 

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A method of identifying the structure"s modal parameters by second order non-stationary source separation(SONS) arithmetic was proposed only using structure"s vibration response signals.On the basis of introducing the process of SONS algorithm and the steps of using BSS method to identify modal parameters,an experiment was carried out using the hammering signals of simply supported beam, and the response signals with noise were analyzed. The experiment demonstrates that the structure"s low order mode shape, natural frequency and damping ratio are picked

up by SONS method accurately.The SONS algorithm has good noise immunity, and its separation results are better and more steady than SOBI(second order blind identification) algorithm.Aiming at the phenomenon where high order modal parameters can not be identified very well using direct BSS method, a method of doing BSS after signal filtering was proposed and high order natural frequency was identified by this method successfully.

Research and Implementation of Multiple Parts List for Assembly Drawings in CAD

ZHANG Wei-Guo, WANG Ya-Guang, LUO Nian-Meng

2011, 22(12):  1459-1465. 

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A solution which supported multiple parts lists for two-dimensional CAD software was present. In the solution, multiple assembly drawings were supported in a CAD drawing, and each of them had independent parts list. With organizing the parts list related objects by “observer-subject” mode, the parts information and the graphic components were separated, data redundancy and object coupling were reduced, and the organization and retrieval of data were simplified. At the same time, intelligent modification and data update were supported. The applications show that the design efficiency for assembly body is improved by the solution, and the incidence of errors is reduced.

Chaotic Transfer State Space Model of Quality Characteristics Variation for Complex Products

LIN Xian-Lin, ZHANG Gen-Bao

2011, 22(12):  1466-1471. 

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Aiming at transfer and control of quality characteristics variation for complex products, a chaotic-fractal transfer pattern was established in nonlinear coupling quality systems. Evolution rules of quality characteristics variation were put forward under analyzing nonlinear and chaotic characteristics of quality characteristics and deciding region of chaotic critical spot on structure parameters of complex quality system was discussed. Chaotic state-space mathematical model of quality characteristics variation transfer was conducted and a calculation model example for complex product assembly process was given. Finally, an instance related with the project on the direct-drive gear hobbing machine was given to prove that the proposed theories and model can solve quality characteristics variation transfer problem effectively.

Failure Rate Model of Mechanical Components Based on Four Elements

WANG Zheng

2011, 22(12):  1472-1476. 

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The factors affecting the typical failure rate curve were analyzed,and four elements including load, strength, strength degradation and life index(namely, the number of load application and time) were proposed for calculating the failure rate of components. Taking the number of load application and time as the life index, respectively, the failure rate models of components consisting of four elements were developed, which can embody the parameters of load, strength, strength degradation and life. Then, the behaviors of the reliability and failure rate of components changing as the life index were studied. The results show that the failure rate curves of components have the partial or whole characteristics of bathtub curve. For different parameters of load, strength and the rule of strength degradation, the failure rate curves of components have different shapes. The models derived herein can calculate the failure rate of components as long as the known parameters of load, strength and its degradation and life index,

and can direct the reliability-based design of components more scientifically.

Statistic Eigenvalue Analysis of Random Beam Structures Based on Substructure Recursive Approach

MO Shen-Hua-1, 2, HUANG Bin-3, GAO Hong-Bei-4

2011, 22(12):  1476-1479. 

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A new numerical method,called as substructure recursive stochastic finite element method,which combined component modal synthesis method with recursive stochastic finite element method,was employed to study eigenvalue problems of random beam structures.The numerical examples of truss cantilever beam show that,compared with perturbation stochastic substructure method based on the first or second order of Taylor expansions, the results of the substructure recursive stochastic finite element method supposed herein are more close to that of Monte-Carlo simulation method in wide range of random fluctuation. 

Research on a Kind of Adaptive Flow Regulator 

WEN Yan, LIU Ban, LI Na

2011, 22(12):  1480-1483. 

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To compensate for the uneven distribution of cooling air volume on the bed surface of grate cooler caused by the thickness change of clinker,based on the hydromechanical continuity equation in the cylindrical coordinates,an analysis and design computation formula of flow regulator for clinker grate cooler were established.Using the variable stiffness leaf springs as the control elements, a new type of mechanical self-controlled flow regulator was designed. The tests indicate that the new regulator can achieve adaptive adjustment of the air flow on every grate element and the purpose of homogenizing the distribution of the cooling air volume.

Study on Design and Tests of a Piezoelectric Linear Motor Using Columnar Actuator

CHEN Pei-Hong, WANG Yin, HUANG Wei-Qing

2011, 22(12):  1484-1488. 

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In order to develop piezoelectric linear motor with high resolution,wide frequency response and long stroke,a cylinder type piezoelectric linear motor using piezoelectric stacks which were preloaded by disc springs was proposed.The operating

principles of the motor were presented,the motor structure was designed, a prototype was made and the experimental study was proceeded.The experimental results show that within a certain range of frequency the vibration amplitude of the stator driving foot is 2μm, the maximum no-load velocity of the motor is 3.7mm/s,and the maximum thrust force of the motor is 4.3N.

Research on Effects of Gap on Weld Quality of Unequal-thickness Blanks Tailored Laser Welding and Its Compensation Method

CHEN Dong-1, 2, 3, DIAO Meng-Yang-1, SHU Tian-Xu-1, SHU Sai-Dun-1

2011, 22(12):  1489-1493. 

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Sunken weld is one of the common defects of tailor welded blanks, which seriously affects the strength of weld,and gap is the main reason for sunken weld.The effects of gap on weld quality and reasons for gap were studied, and the relationship between gap and process parameters was discussed based on theoretical analyses and experiments.The results show that gap relates to offset, blank thickness, weld width and the minimum melting width of thinner blanks. The minimum melting width of thinner

blanks was related to the materials of blanks.Positive offset can compensate the harmful effects of gap.The models for the maximum gap and offset tolerance were proposed,and a compensation method was also given, thus the adaptability of the gap was enhanced. The results can provide theoretical guidance for the optimization of process parameters.

Study on Processing Strategy of Singly Curved Surface Based on Plastic Strain Field in Laser Forming

DAN Yong-Jun-1, LIU Yan-Cong-1, HU Dun-2

2011, 22(12):  1493-1497. 

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To obtain high accurate shape with singly curved in laser forming,a new design approach was proposed based on plastic strain field.Firstly, a plastic strain field required to obtain a desired shape was obtained by finite element analysis.The heating paths were planned using the above plastic strain field. The process parameters were determined according to the basic relationship database between the process parameters and the residual plastic strain. In order to quickly evaluate the validity of the process strategy, a method of finite element simulation based on an equivalent load model was given.The experimental results based on the above process strategy show that the laser forming shape is approximately consistent with the desirable shape.

Effects of Nano-ZrO₂ on Friction and Wear Behaviors of MoSi₂ Coating at High Temperature

HU Xiao-Beng-1, YA Jian-Hui-1, ZHANG Hou-An-2

2011, 22(12):  1498-1502. 

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MoSi₂ and ZrO₂-MoSi₂ coating were prepared by air plasma spraying.The friction and wear properties of two coatings at 1100℃ were studied and the wear mechanism was also analyzed by XRD and SEM technology.Results

 show,with load increasing, the friction factor of MoSi2 and ZrO₂-MoSi₂  coating

 reduces gradually.With the addition of nano-ZrO₂ into MoSi₂,the friction factor of MoSi₂ coating reduces and the adhesion resistance is improved. With the load increasing, the wear mechanism of MoSi₂ coating changes from adhesion wear to

brittle fracture, but the oxidation wear accompanies all along. The main wear

mechanism of 30%ZrO₂-MoSi₂  coating are oxidation wear and mild adhesive wear. When the load increases to 40N, the brittle flaking-off also exists. Nano-ZrO₂ can reduce the brittle flaking-off of MoSi₂ coating.

Kinematics Analysis and Optimization of 3D Vibration Damping Platform of Vehicle Seat

TUN Wei-Guang, MA Lv-Zhong

2011, 22(12):  1503-1507. 

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A new three-translation parallel mechanism was designed to resolve the problem of three-dimension vibration in vehicle seat. The kinematics of the platform was analyzed and the workspace and singularities was researched by software of MATLAB.Then the dexterity in workspace was analyzed and the relations between geometrical parameter, workspace and dexterity were studied.Finally the parameters of platform were optimized.For analyzing the vibration damping performance of the platform,

a simulation model was built in MATLAB/Simulink, and the results indicate that the parallel platform is suitable for three-dimension vibration isolation in vehicle seat.

Simulation Research of Steering Stability of 4WS Vehicle Based on Lateral Displacement Error Control

YOU Yong-1, HUANG Dun-Jie-2, WANG Gao-2, KUANG Kun-Yang-2

2011, 22(12):  1508-1511. 

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