Table of Content

10 May 2011, Volume 22 Issue 9

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Research on an Algorithm for Prediction of Aeroengine Performance Deterioration

ZHANG Ying, ZUO Hong-Fu, LIN Chu-Gong, SHU Lei

2011, 22(9):  1009-1013. 

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Process neural networks were adopted to predict the engine gas temperature margin,which could reflect the performance deterioration of the civil aviation aircraft engine. In order to overcome the problem that the learning speed of existing learning algorithms for process neural network was slow, a chaotic particle swarm optimization based on Tent map was developed, which could improve the convergence speed and prediction accuracy. Simulation results demonstrate the validity and feasibility of the proposed algorithm.

Characteristic Analysis and Localization of Acoustic Emission Source Based on Chaos Theory

CHENG Xin-Min, HU Feng, DENG Ai-Dong, DIAO Li

2011, 22(9):  1013-1017. 

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A nonlinear dynamic analysis of the acoustic emission (AE) signals in rotor rubbing was conducted based on the chaotic signal processing technique and such new features of nonlinear dynamics as correlation dimension, largest Lyapunov index and the Kolmogorov entropy were proposed herein. Simulation results reveal the neural network model employing these new features improves the localization efficiency of the AE source and contributes to the diagnosis of rotor rub-impact faults.

Dynamic Reliability Analysis of Catenary under Wind Load

CAO Shu-Sen, KE Jian, LIU Xiao-Gong, DENG Bin, MA Jia-Dun

2011, 22(9):  1018-1022. 

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To improve effectively the shortcoming of time-consuming large in using directly Monte Carlo method, the theory of artificial neural networks and Monte Carlo algorithm combined with analysis of finite elements (simplified as the FE-RBF-Monte Carlo method) were applied to dynamic reliability analysis under wind load. It is done to organically combine with the finite element numerical analysis, high-powered RBF-NN and Monte Carlo method, then the feasibility of this method was proved by an example. The analysis indicates that the method is feasible, effective, and of high accuracy; it improves effectively the shortcoming of time-consuming large in using directly Monte Carlo method. The method provides a new way for dynamic reliability analysis of a complex catenary. 

Research on Fractal Profile Synthesis Method for Determinating Height Deviation and Bearing Rate

ZHOU Chao, GAO Cheng-Hui

2011, 22(9):  1022-1025. 

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Based on fractional Brownian motions and discrete Fourier transform, the traditional characteristic parameters of fractal profiles were studied. It is found that with given sampling points, if the double logarithmic power spectrum of a fractal profile is assumed to be linear, the quantitative relationship between the profile’s root mean square roughness and its fractal parameters can be established based on the theorem of Parseval.And because of the randomness of phase spectrum, the material ration and arithmetic average height of the profiles are still different even though the fractal parameters are the same. Through enough random experiments, a profile with given fractal parameters, root mean square roughness, bearing rate and arithmetic average height can be synthesized.

Development of Fast Analysis Software for Sheet Metal Forming Based on SolidWorks

QIN Ning, ZHANG Zhi-Bing, HU Heng-Jian, LIU Yu-Qi

2011, 22(9):  1026-1030. 

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A process-oriented sheet metal unforming simulation system SW-BEX（stamping works-blank estimation xpert） with pre-process and post-process was developed, which was integrated into SolidWorks software and based on the inverse approach of FEM. The design process and development process of SW-BEX was introduced, and some key techniques of the system development were studied, such as meshing and constraint definition. By analyzing a typical sheet metal using SW-BEX, the easy operating, practicality of this system are demonstrated, and the simulation accuracy of this system was verified by comparing the simulation results with the experimental ones. SW-BEX is fully integrated into the SolidWorks platform, avoids the problem of accuracy loss caused by model data exchange between CAD platforms and traditional CAE software, and achieves the real CAD/CAE seamless integration. 

Contour Control for Direct Drive XY Table Based on Real-time Position Compensation and Repetitive Control

WANG Li-Mei, LI Bing

2011, 22(9):  1030-1034. 

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The contour accuracy of a direct drive XY table driven by the PMLSM was influenced by end effect and friction of the XY table for time-varying free-form contour following task. To enhance the contouring performance, a contour error algorithm applicable for multi-axis nonlinear motion system was adopted. PEC and a cross-coupled controller were combined to make the contour error approach to zero. A compound control scheme based on combining RC and a PDFF speed controller were employed herein. Theoretical analyses and simulation results show that the designed control system makes XY table possess high performance of contour accuracy, and reduce the influences of the periodic disturbances of XY table system.

Carbon Footprint Based Multilevel Hierarchical Production Process Control

SUN Qun, ZHANG Wei-Min-

2011, 22(9):  1035-1038,1111. 

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On the ground of resource and environmental attribution in manufacturing enterprise production process analysis, a carbon footprint was proposed as the unified quantitative indicator to evaluate resource and environmental attribution, optimum process control for production process. The relationship constraints among resource and environmental attribution and production control were discussed. Moreover, a multilevel hierarchy control system was established with the support of database, model base and knowledge base. This system offers a theoretical support for resource quantitative evaluation and production process control. 

Dynamics Modeling and Simulation for Deployment of Repeated Fold-unfold & Lock-unlock Solar Wing

HU Meng, CHEN Chang-Ju, CHEN Wen-Hua, BO Jun, WU Qiu-Gong

2011, 22(9):  1039-1044. 

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A repeated fold-unfold & lock-unlock solar wing was taken as a study object herein. According to the transmission order of the repeated fold-unfold & lock-unlock joint hinge, the kinematics analysis of the solar wing deployment mechanism was carried out. Using the Kane dynamic equation, a dynamics model of solar wing deployment was established. Based on ADAMS, the simulation model of solar wing deployment model was made, and the structure parameters of a principle prototype were used to compute theoretical and simulation values of the driven torque for the repeated fold-unfold & lock-unlock solar wing. By contrasting theoretical and simulation values, dynamics modeling theory for the repeated fold-unfold & lock-unlock solar wing was validated. 

 

Research on Testability Comprehensive Evaluation Method for Engineering Equipment

SHU Chun-Sheng, ZHANG Qi, DAN Gong-Liang, JIAO Yu-Min

2011, 22(9):  1044-1048. 

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An analytical hierarchy model of testability comprehensive evaluation for engineering machines was built, and the influence weights of testability quality in different states of design were computed. The model for the assessment was founded by FCA. Based on the model, the comprehensive assessment values were computed and the evaluation results were made. A case shows that this approach can trade off the influence factors via combining the AHP with FCA, which can make a testability comprehensive evaluation effectively for engineering equipment.

A New Permanent Magnetic Operating Mechanism and Its Control Scheme

SONG Lan, WANG Fa, SHAO Chang-Xing, WANG Yong

2011, 22(9):  1049-1053. 

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This paper introduced the developing history of permanent magnetic operating mechanism(PMOM), which was electromagnetic drived and permanent magnetic kept, and analyzed the recent research work by researchers on how to improve the performance of PMOM. As the performance of a typical PMOM was not ideal and the structure of the improved PMOM was complex, a new permanent magnetic drived and permanent magnetic kept operating mechanism was proposed. Its working principles were introduced, its static characteristics was analyzed, and its control scheme was given. Compared with the typical PMOM, this new operating mechanism has more simple structure and more flexible control scheme.

Flexible Multibdoy Contact Dynamics Analysis on Angular Contact Ball Bearings

TAO Ting-Jiang, TAN Yang, WANG Li-Da

2011, 22(9):  1054-1059. 

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With the effect of structural elastic deformation of rings and boundary conditions, the paper tried to propose a new dynamics hybrid computing method on angular contact ball bearings based on combining finite element method and dynamics of multibody system. Considering dynamic contact between balls and ring’s races, the new multi-flexible bodies contact dynamics analysis models of angular contact ball bearings were established by ADAMS. The calculation programme was written for dynamic contact force based on penalty method. Considering the effect of different load parameters, rotate speed and centrifugal force, the distributions and rules of dynamic contact force, contact angle, vibration displacements, dynamic contact stress and strain were discussed. The new dynamic analysis model and simulation results have significances in guiding the design, analysis and application of angular ball bearings with the purpose of vibration and fatigue life with heavy loads, impact loads or complex loads.

Hierarchical Case Based Reasoning Method for Assembly Sequence Planning of Automobile Body

LIU Hai-Jiang, BO Zhen-Hua

2011, 22(9):  1059-1066. 

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A novel HCBR(hierarchical case based reasoning) method for auto-body assembly sequence planning was presented. Firstly, assembly information was modeled, and assembly planning was defined as a case. Through hierarchical representation and organization of the assembly information knowledge, an index scheme of case base Bayesian network was established. A computation method of comprehensive similarity was implemented to retrieve the most similar case for reuse. After case matching and adaptation, the feasible assembly sequences of aim case were finally obtained. The effectiveness of the method was verified by the results of front rail assembly and comparison

of related algorithms.

Fault Diagnosis for Hydraulic Pump Based on Gradual Asymptotic Weight Selection of Wavelet and Adaboost

LI Qing, ZHANG Pei-Lin, TUN Ding-Hai, XU Chao

2011, 22(9):  1067-1070,1075. 

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In order to solve the problem of identifying incipient faults of a hydraulic pump, a novel method of fault diagnosis based on gradual asymptotic weight selection of wavelet and Adaboost ensemble was proposed. Aiming at the features of incipient faults not abstracted effectively, based on optimization theory, selection of gradual asymptotic weight by using the signals from traditional wavelet was to get the higher SNR factor of denoised signals. The denoised signals were used to select the optimal features. Then, aiming at the problem of neural network’s over-learning and under-learning, the optimal features were trained with Adaboost algorithm to identify the different fault cases. Testing results show, compared with traditional wavelet, gradual asymptotic weight selection of wavelet can denoise, improve SNR factor, and abstract the optimal fault features effectively. Adaboost algorithm has a higher classification success rate than the BP neural network.

Application and Study of CBR in Tube Welding Flexible Fixture Design

ZHANG Qing-Wen, LI Xia, TUN Chun-Qiao

2011, 22(9):  1071-1075. 

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Owing to a lot similarities in the welding tube,the CBR method was applied into the welding tube flexibile fixture design herein.The feature of workpiece and fixture were considered in the case similarity.The design rules and coordinate transforming technique with the secondary development technology based on Solid Edge were used to modify the case in order to assemble automatically. The application of the algorithm based on the knowledge in the retrieve of the similar cases,the strategy of case adaptation and case storage, improves highly the reuse of design knowledge, decreases repetitive work and solves the problem which the intelligence level of the fixture redesign in new case is not high.

Improved Negative Selection Algorithm Based on Clonal Selection and Neighborhood Search

HU Rong-Hua, LOU Pei-Huang, TANG Dui-Bing, DIAO Feng

2011, 22(9):  1076-1080. 

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Based on the study of genetic RVNS algorithm(GA-RVNS), an improved RVNS based on clonal selection and neighborhood search(CSNS-RVNS) was proposed. To solve GA-RVNS’s premature convergence and its detector sets were not optimal in N-dimensional space, a clonal selection of the immune mechanism was introduced to implement global search. A quasi-random sequence was generated to serve as the search space of clonal selection, then the optimal detector sets in sequence were obtained by clonal selection and mutation operators. The Gaussian mutation operator was proposed to get the global optimal detection sets of N-dimensional space through neighborhood search. The resulting detector sets achieve a good coverage of non-self space, and also significantly reduce the number of detector sets, thus overcome the limitations of original negative selection algorithm. Finally, experiments verify the effectiveness of the algorithm.

Research on Tooth Surface Deviation Correction Algorithm of Spiral Bevel Gear Based on Tilting Method

CHEN Shu-Han, YAN Hong-Zhi

2011, 22(9):  1080-1084. 

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According to the characteristics of the tooth surface deviation identification model of spiral bevel gear and defects of the least squares method solving, TSVD and the L curve method were proposed. The identification equation was solved to use TSVD and the L curve method and the least squares method separately. The research results show, to the concave, using TSVD and the L curve method, the equation solution error is 0.051 571, but using the least squares method, the equation solution error will be 0.895 63; to the convex, using TSVD and the L curve method, the equation solution error is 0.043 882, but using the least squares method, the equation solution error will be 0.353 76. Using TSVD and the L curve method this tooth surface deviation identification equation is solved more precisely, and the obtained solutions are meaningful. 

Evaluation Study on Orderliness of Product Digital System Structure in Dissipative Structure Sense

AI Pan-Di, LIU Zi-Jian, MO Jing-Jing

2011, 22(9):  1085-1090. 

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The relationship between dissipative structure and order degree was discussed,information aging entropy and information accuracy entropy were proposed,which can be used to measure order degree of system structural order and was related closely to orderliness of system structure in a product digital system. Sequentially, information aging entropy and information accuracy entropy became important order parameters which evaluated orderliness of system structure of the product digital system. The calculation methods of information aging entropy and information accuracy entropy and system structure order degree were proposed and the calculation model of structural order degree of product digital system was given. A design example of stamping tool of sheet metal was completed respectively by introducing new product digital system of model-oriented design pattern and product digital system of traditional patterns, both system structure order degrees were computed and analyzed and the validity of calculation model of structural order degree was verified, which provides the theoretical lesson for quantitatively research evolution feature of digital system products based on dissipative structure theory.

Analysis on Deterioration Layer and Cracks of Monocrystalline Silicon Cut by WEDM

GAO Lian, LIU Zhi-Dong, QIU Meng-Bei, TIAN Zong-Jun, HONG Wei

2011, 22(9):  1090-1095. 

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Using monocrystalline silicon cut by WEDM as the research object a diathermanous and mathematics model was establish. Analogue computation was carried out with ANSYS simulation software, and the distribution of transient temperature and stress field were obtained. Then a hierarchical preferential etch experiment along the vertical orientation of monocrystalline silicon surface cut by WEDM was carried out to observe the corrosion morphology changes, the thickness of the deterioration layer was determined. The law of the deterioration layer thickness affected by electrical parameters was summed up and comparing to the simulation results, the correctness of the model was proved. The results show that: discharge voltage and pulse width are main factors which affect the deterioration layer thickness; the crack appeared in the metamorphic layer will increase rapidly as the discharge energy increases, and even can be expanded to crystal zone when energy increases to a certain degree. At this point the depth of the crack can be regarded as metamorphic layer thickness.

Dynamic Stiffness Analysis on Direct Drive Spindle System

HUANG Jiang, CHEN Kun, ZHANG Gen-Bao

2011, 22(9):  1096-1099. 

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To improve the anti-vibration performance of a direct drive workpiece spindle system on YK3610 hobber, a new way for system structure analysis and optimization was proposed. The optimization object was dynamic stiffness of this system. Making use of three-dimensional finite element model, the regularity about several important design parameters working on the system dynamic stiffness was investigated. During this work, the correlation characteristics of these design parameters should be analyzed purposefully. The analysis results about the reasonable position of rotor and the correlation characteristics of design parameters, should be important direction action in framing the whole optimization scheme for the direct drive spindle system.

An Uncertainty Multi-objective Optimization Based on Interval Analysis and Its Application

LI Xin-Lan, JIANG Chao, HAN Xu

2011, 22(9):  1100-1106. 

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An interval multi-objective optimization method was suggested based on non-linear interval analysis methods. The upper and lower bounds of every objective and constraint functions for each vector were calculated,by using the center value of the interval objective function,the non-dominated solution of the multi-objective optimization problems was calculated,with the interval possibility degrees,the nonlinear interval multi-objective problems were changed into the deterministic multi-objective problems.The μMOGA was used to calculate the converted deterministic multi-objective problems. Finally,the method was applied to one numerical example and two engineering problems about ten truss structure and commercial automobile frame optimization. The results of these examples demonstrate the efficiency and engineering practicability of the presented method. 

Study on Measuring Method and Distribution Law of Stress of Contact Area between Bonnet Polishing Tool and Workpiece

JI Shi-Ming, ZHENG Gao-An, JIN Meng-Sheng, ZHANG Li, ZHANG Wei-Dong, HOU Hai-Feng

2011, 22(9):  1107-1111. 

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A measuring method for contact area stress distributions measurement between rubber indenter and rigid surface was proposed. The temperature of contact area was changed by vibration contact, and temperature distribution was obtained with the aid of infrared temperature-measurement. Based on Hertz contact theory and thermoelastic effect, the relationship among the material properties, contact stress distribution and the temperature change was established, and it was validated by taking the contact area between rotator rubber indenter and rigid flat surface as an example. The results show that the temperature and the stress lines change as the “M” in the contact area. The temperature has a positive correlation with the stress. Meanwhile, it is correlated with the raw material properties, such as the thermal diffusion coefficient, thermal diffusivity and coefficient of thermal conductivity.

 

Discussion of Objective Functions in Heat Conduction Topology Optimization

JIAO He-Ting, ZHANG Yong-Cun, LIU Shu-Tian

2011, 22(9):  1112-1117,1122. 

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Using geometric average temperature as a good approximation for the maximum temperature which was proposed as the objective function into heat conduction topology optimization model, and a new design model was developed for heat conduction topology optimization. Sensitivity of the new objective function was derived by using the adjoint method. By comparing the maximum temperature, the maximum temperature gradient, and the nodal temperature with the design results respectively, the differences among these three models as well as their scopes of application were discussed through theory and numerical analyses.

Study on Modified Involute Profile Roller Chain Sprocket and Its Dynamic Features

JI De-Sheng, HUANG Xue-Gong, WANG Yong

2011, 22(9):  1118-1122. 

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Through modifying the profile of an involute sprocket, the equation of modified involute sprocket profile was derived. A multi-body dynamic model of double overhead camshaft timing chain was constructed and the dynamic simulation ranging from low speed to high speed for the timing chain system was achieved. Comparing the simulation results of using GB1244-76 sprockets，DIN8196sprockets and modified involute sprockets, the results show that using the modified involute sprocket can reduce meshing impact and friction force between chain and transmission parts, so as to reduce the noise and lengthen the life of chain and sprockets.

Application of Factor Analysis in Driving Cycle Development

DAN Qin, ZHENG Yu-Bei

2011, 22(9):  1123-1127. 

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As for the reseach of construction process of vehicle driving cycle, a method of factor analysis combined with fuzzy clustering was proposed herein,and a representative driving cycle was developed urban roads by this method. The method of factor analysis was applied to reduce the characteristic parameters of many microtrips, all microtrips were classified by using 3 common factors that can represent most of the features of the original microtrips; Based on the results of cluster analysis and the correlation coefficient theory,some representive microtrips were extracted from each type of microtrips to construct a typical driving cycle. The application of the driving cycle model to the roads in Hefei city shows that the average error in obtained typical driving cycles is 13.01% compared with the experimental data in terms of V-A matrix of the typical driving cycle.So the typical driving cycle can reflect Hefei road traffic condition comprehensively. 

Performance Improvement of Occupant Restraint System Based on Taguchi Robust Design Approach

FEI Lei, CHENG Ai-Guo, LI Tie-Zhu, GAO Hui

2011, 22(9):  1128-1133. 

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