Table of Content

10 August 2008, Volume 19 Issue 15

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Research and Discussion on Theory about Thermal Deformation Errors in Precision Technology

Fei Yetai;Li Guangke

2008, 19(15):  0-1889. 

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In the field of precision mechanism and engineering technology, the thermal deformation errors are often the dominate cause among the factors affecting the accuracy. After years of experimental and theoretical study of the thermal deformation, the authors presented the following theories: thermal deformation coefficient of the part, precise thermal expansion coefficient, non-similarity in thermal deformation of the part, optimal thermal fitting theory of the hole and shaft, and briefly introduced self-developed high-accuracy four-dimensional experimental equipment of the thermal deformation.Finally the main problems being studied subsequently of the thermal deformation theory in the field of precision mechanism was also presented.

Temperature Field Analysis and Discharge Parameter Optimization for Surface Discharge Assisted Truing and Dressing of Metal Bonded Diamond Grinding Wheel

Jia Yan;Cai Lanrong;Hu Dejin

2008, 19(15):  0-1889. 

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A novel truing and dressing method was advanced about diamond grinding wheels, specifically surface discharge assisted truing and dressing of metal bonded diamond grinding wheel. Simulation models of temperature fields were established by finite elements analysis using ANSYS software and observations of surface micro-patterns were made by VH-800 3D digital microscope. Based on the experimental results,parameters for surface discharge assisted truing and dressing of metal bonded diamond grinding wheel are optimized.

Mechanical Characteristics and Design Principles of Underwater Force Sensor Based on Pressure Balance of Film

Wang Yong;Liu Zhengshi;Chen Enwei;Ge Yunjian

2008, 19(15):  0-1889. 

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Based on the condensability of liquid, the structure used in multi-axis force sensor of underwater robot aimed at balancing hydraulic pressure was investigated and an iteration algorithm used to calculate the pressure difference between in and out of the sensor was put forward, which applied the pressure balance method of film. Formulas of pressure difference, additional axial force and so on in the pressure balance method of film were educed. The relative factors especially the pressure difference were analyzed,which affected the additional axial force acting on the sensor. Results show that the pressure balance method of film unfit for high pressure balance while possessing a wonderful ability to balance the slight pressure under high pressure. The criterions in designing the structure of the underwater force sensor of film are summed up, viz. compact structure, small ratio of length and diameter, large film of pressure balance, small thickness of wall and little oil inside the structure.

Dynamics Analysis of a 3-RRS Parallel Manipulator

Liu Shanzeng;Yu Yueqing;Liu Qingbo;Si Guoning;Wang Wenjing

2008, 19(15):  0-1889. 

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This paper presented the dynamics equations of a 3-RRS parallel manipulator based on the Lagrange equation, and addressed the dynamics characteristics of the mechanism. The equivalent moment of inertia, driving forces/torques and consumed energy of the mechanism were analyzed through an example. The results of numerical simulation show that, for a given motion, the configuration has a significant influence on the equivalent moment of inertia and driving forces/torques.

Design and Research of SMA Spring Array Based Artificial Muscle

Ying Shenshun;Qin Xiansheng;Wang Wendan;Wang Zhanxi

2008, 19(15):  0-1889. 

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The shape memory effect exhibited by Nitinol wire can be utilized to construct an artificial muscle. However, the produced strain and recover force were relative small and only suitable for micro-robot. New biology inspired artificial muscle aiming to provide robots with big displacement and notable output force was presented. The bionic configuration of the SMA springs array based artificial muscle was designed and its driving mechanism was analyzed. Then, output force formulation was deduced. Muti-body dynamics model of the artificial muscle was built using UG and ADAMS, then control model under Simulink for simulating the artificial muscle was also established. Performance of dynamic characteristics of artificial muscle was simulated and analyzed by integrating the whole working process of bionic arm. The results show that the SMA springs array based artificial muscle has good simplicity and controllable analog output.

Machining Mechanism and Test Study on Micro-machining of ECM Combined Ultrasonic Vibration

Zhu Yongwei;Wang Zhanhe;Li Hongying;Yun Naizhang

2008, 19(15):  0-1889. 

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Basic tests of ECM combined ultrasonic vibration micro-machining were carried out. The electrochemical passivation mechanism was analyzed. It is verified that anode electrolytic passivation membranes can be removed by the great blast wave and the negative pressure effect produced by ultrasonic frequency vibration. The simultaneous methods of electrochemical machining and ultrasonic vibration were analyzed. The micro-machining system that ECM combined piezoelectric ultrasonical vibration was designed and built. The micro-cathodes of different sections and sizes were manufactured by the nontraditional micro-machining. A series of micro-machining tests were carried out for manufacturing micro-structure, such as micro-shafts, micro-holes, micro-grooves and micro-gears. The possibility and advantages of the technology had been proved. The properties of machining micro-structure were studied. 

Roller Bearing Fault Diagnosis Approach Based on Wavelet Transform and Rough Set Theory

Zhang Bangji;Yu Dejie;Yang Sheng

2008, 19(15):  0-1889. 

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A new method was presented for fault diagnosis rule acquisition based on wavelet transform and rough set. It linked the wavelet and rough set theory. The method was applied to roller bearing fault diagnosis successfully. It gives a higher fault diagnosis ratio using energy feature than the traditional method using time and frequency parameters. It proposes a new method for fault diagnosis of roller bearings and other machine equipment, and gives a new method for building the simpler knowledge base of intelligent fault diagnosis system.

Numerical Algorithm of Tooth Profile of Noncircular Gear Based on the Characteristics of Cutter Envelope

Wu Chuanyu;Jin Yuzhen,;He Leiying

2008, 19(15):  0-1889. 

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According to the theory and real process of tooth profile generation with rack-shaped cutter, the kinematics model of cutter in the machining simulation system was presented. With the analysis of the tooth profile generation in the simulation process, the tooth profile was described as feature point set, and the generating rule of the tooth profile was summarized. Moreover, the numerical algorithms of the whole tooth profile data, which included the feature point, fillet and addendum curve, were proposed. The software of tooth profile for elliptical gear was programmed, which could be used by wire electric discharge machining for the elliptical gear’s machining. The elliptical gear machined by this method has been used successfully in the rice transplanter and its test platform, which verifies the feasibility of the method.

Study on Natural Torsional Vibration Characteristics of Dual Mass Flywheel-radial Spring Type Torsional Vibration Damper

Li Guanghui;Hu Jianjun;Qin Datong

2008, 19(15):  0-1889. 

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The operation principle of dual mass flywheel-radial spring（DMF-RS） type torsional vibration damper was analyzed, and the design method of natural torsional vibration characteristics control of DMF-RS type torsional damper for automotive powertrains was studied herein.Based on the multi-freedom with mass-spring torsional vibration analysis model of powertrain system, the natural torsional vibration characteristics of the system with DMF-RS type torsional damper were analyzed, and compared with the clutch type torsional vibration damper, the effectiveness of DMF-RS type torsional damper on the torsional vibration control was verified.

Experimental Study of H∞ Robust Control for Flexible Plate Vibration System Based on Piezoelectric Chips

Li Dongwei;Bai Hongbai;He Zhongbo;Hou Junfang

2008, 19(15):  0-1889. 

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There are design calculations, simulation and tests of robust active vibration controller based on one flexible plate bended piezoelectric actuators and sensors. Firstly, the multi input multi output(MIMO) transfer function model of three modals of the plate vibration system was identified by the multivariable frequency-domain identification theory. Then, by means of frequency weighted transformation of the flexible plate model with residual modal multiplicative uncertainty according to the performance of disturbance suppression, control gain restrain and robust stabilization,a mixed sensitivity robust controller was established. The results of simulation proves the rationality of the controller and the weighted functions. After the active vibration control tests of initial disturbance and random disturbance, the results verify that compared to the LQR controller, the controller can achieve better performance under the condition of system robust stabilization, the attenuation time is shortened 30s, the noise reduction is increased 4dB.

Optimization Design of CVT Cooling System Based on Improved Particle Swarm Optimization Algorithm

Zhou Yunshan;Liu Jingang;He Xiahui;Li Quan

2008, 19(15):  0-1889. 

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A method for optimization design of continuously variable transmission cooling system based on improved particle swarm optimization algorithm was presented herein. The basic design scheme of the whole cooling system was determined firstly. And then, considering energy loss properties and cooling pressure control valve operating characteristics, key structure parameters of cooling system were optimized based on the improved particle swarm optimization algorithm. The results of simulation and complete vehicle test prove that the designed cooling system can realize more excellent global and local cooling flux distribution, and can satisfy cooling requirements under any extreme operation conditions. 

Dynamic Scheduling Optimization Strategy Based on Memetic Algorithm

Zhang Guohui;Gao Liang;Liu Wenjun

2008, 19(15):  0-1889. 

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Based on rolling-horizon procedure, a memetic algorithm was proposed to solve the dynamic job-shop scheduling problem. In this procedure, periodic and event driven rescheduling strategies were employed to decompose the scheduling process into a series of continual and static scheduling problems, and the Memetic algorithm was applied to solve each of the static scheduling problems. The order crossover and a new mutation based on neighborhood search were employed in the Memetic algorithm. After each crossover and mutation operation, an improved simulated-annealing algorithm was utilized for local search. A modified job-shop benchmark instance was tested, and the experimental results show the effectiveness of the proposed strategy.

Digital Manufacturing Shop Based on Digital Human

Dong Bolin;Wang Zhisen;Wang Chunxian

2008, 19(15):  0-1889. 

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By utilizing the mobile communication and mobile computation technology,this paper put forward the concept of digital human (DM) and built DM prototype. DM accessed to digital manufacturing shop in real time, obtained information through sense, made judgment according to imaginal thinking, intuition and experience, and integrated seamlessly with machine intelligence which was based on long-term storage, exact inference and quick data processing to realize flexible and convenient optimal manufacturing decision-making. Based on DM conception, authors built the new type of digital manufacturing shop which supported DM, analysed the network architecture and function modules of this shop floor. Finally, integrated with multi-agent technology, authors analysed the operation model of this shop floor.

Research on Configuration Decision Model Based on Weighted Directed Graph for Reconfigurable Manufacturing System

Lü Chao;Li Aiping;Xu Liyun

2008, 19(15):  0-1889. 

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In order to attain the system configuration and analyze the impact of the configuration on performance rapidly and effectively, a modeling method based on weighted directed graph was presented according to characteristics of RMS. By using modular method, some sub-models were achieved according to functionality of RMS.The integrated configuration decision model was attained by anglicizing and clustering the adjacency matrix, accessible matrix and conjunction matrix, this model can give performance reference data to system configuration. The sensitivity and expansibility of this model were integrated by analysis the weighted conjunction matrix, an application was presented to illustrate the effectivity of the model. 

Cutter Layout Design of Full-face Rock Tunnel Boring Machine(TBM)

Huo Junzhou;Shi Yanjun;Teng Hongfei;Chai Rongfeng;Zhang Lihua

2008, 19(15):  0-1889. 

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A cutter layout method of the full-face rock TBM was proposed, in which the technological requirements of the cutter layout were summarized, then the rock-broken volume estimation method for the non-equality cutter space was given and a nonlinear multi-objective cutter layout mathematical model with complex constraints was established.Further, based on the coupling analysis of the multi-objectives and constraints of the mathematical model, a hierarchy solving strategy of polar radius and polar angle was given and the genetic algorithm (GA) was used to solve cutter layout design of the full-face rock TBM. Finally, taking some imported full-face rock TBM cutter layout design as an experimental example, compared with the computational results of the original layout design, the experimental results show that the proposed cutter layout mathematical model and corresponding solution strategy are feasible and effective.

Active Vibration Control for Flexible Piezoelectric Manipulator Based on Fuzzy-PID Fusion Control

Yu Yueqing;Zhou Gang;Fang Daoxing

2008, 19(15):  0-1889. 

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Based on fuzzy-PID fusion control theory, a method of vibration control for the flexible manipulators with piezoelectric smart structure was presented. A cantilevered beam, experimental setups of 1R and 2R flexible manipulators were built, and their control systems were developed. The vibration control of the all flexible manipulators was achieved by experiments. The experimental results show that the proposed method is of simple arithmetic and real-time characteristics without the dynamics model of the manipulators and has good robustness and fast response for vibration control of flexible manipulators.

Design Behaviors Capture Based Lightweight Design History Management Research

Fu Xiangjun;Peng Yinghong

2008, 19(15):  0-1889. 

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Most research projects focus on product model based knowledge representation pattern to build design rational systems, while neglect the bottleneck of knowledge acquiring. A lightweight design history management framework was proposed, which combined with the design event ontology and an activity knowledge acquisition method that can captures the designer’s behavior without distracting designers from their normal design processes. In order to acquire the design intent knowledge, a Naive Bayes approach was taken to predict the goal task of design events and plan recognition method to discover the plan level procedural knowledge. 

A Mathematical Modeling Method and Experimental Investigation on Micro Heat Pipe with a Rectangle-grooved Wick Structure

Li Xibing;Li Yong;Xu Zechuan;Tang Yong

2008, 19(15):  0-1889. 

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South China University of Technology, Guangzhou，510640
By analyzing and deducing the factors influencing its structure, strength and heat transfer limits,this paper was to establish the heat transfer models of circular micro heat pipe with a rectangle-grooved wick structure, including the models of viscous limit, sonic limit, entrainment limit, capillary limit, condensing limit, boiling limit, continuous flow limit and frozen startup limit. It was also to establish the model of strength theory and to testify by means of experiments the correctness of the heat transfer models thus built. The study lays a powerful theoretical foundation for the design and manufacture of circular micro heat pipe with a rectangle-grooved wick structure.

Study on Ontology Based Technical Innovation

Jiang Liang;Sun Tiebing;Qu Fuzheng

2008, 19(15):  0-1889. 

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The scientific principle of technical innovation often comes from other domains. The larger the span between domains is, the higher level of innovation we will get. By combining ontology and semantic technology, which aimed to realize reuse and sharing of information and knowledge, with theory of inventive problem solving TRIZ, method of solving technical conflict based on ontology was proposed and the flow chart of solving technical conflict based on ontology was given. By making use of ontology construction software protégé and ontology description language OWL, on the basis of technical conflict solution theory, which came from TRIZ, the technical innovation ontology was constructed, which will pave the way for ontology based technical innovation in semantic web in the future. The validity of this method was proved by a case study, which described technical innovation of critical part of dynamic compaction machinery self-release mechanism. 

Fault Diagnosis of Bearings Based on the Wavelet Grey Moment Vector and CHMM

Xu Zengbing;Xuan Jianping;Shi Tielin;Wu Bo;Hu Youmin

2008, 19(15):  0-1889. 

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According to the essential characteristics of fault diagnosis of mechanical equipment and traits that continuous hidden Markov model (CHMM) has the great ability of classifying time sequence pattern, a method of fault diagnosis based on the wavelet grey moment vector and CHMM for the rolling bearing was put forward. A nondimensional wavelet grey moment vector which was extracted from the vibration signals was used as the feature parameters, and they were used to train the CHMMs of some fault states, then these trained CHMMs were applied to identify the states and fault patterns of bearings. At last, the experimental study verifies that the method of fault diagnosis for the bearings is effective with small training samples.

An Un-empirical Model for Probability Prediction of Common Cause Failures in Systems

Zhou Jinyu;Han Wenqin;Zhu Fuxian;Xie Liyang

2008, 19(15):  0-1769. 

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The generating and coupling mechanism of common cause failures was studied based on load-strength interference theory and the regularity of the common load giving rise to element failure dependency whereas strengths of components were independent was brought to light. Establishing the relationship among the common load variance, component strength variance and component failure dependency by correlation coefficient, an un-empirical model for probability prediction of common cause failures was derived. Considering the facts that low-order failure data being known and distributed functions of common load and component strength being unknown, a practical method for common cause failures probability assessment was put forward. Different from the conventional model, the new model and method embody the inherent mechanism of common cause failures with overcoming shortages of depending field data or subjective experience too much, which gives a new path for risk data analysis, failure probability prediction and reliability design of redundant systems.

材料工程

Reseach on Viscoe-elasticity Plasticity Unified Constitutive Relationstip of Vibrational Rotary Forging and Its Hysteresis Procedure Simulation


Cai Gaipin;Jiang Zhihong;Luo Xiaoyan

2008, 19(15):  0-1889. 

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As viscoe-elasticity-plasticity material constitutive relationship was analyzed, a hypothesis yield face which was not effected by temperature was popularly used to suppose viscoe-elasticity-plasticity material deformation trend, and the inherent law of metal material in heat deformation was difficultly opened out by this method. Thus, the viscoe-elasticity-plasticity material constitutive relationship needed to be built by the continuum mechanics theroy and thermodynamics under the conditions of temperature field effect consideration and the hypothesis yield face overcame. After motion hardening variable and the identification hardening variable introduced, the inner variables and stress evolvement course were analyzed in heat steady state creep forming, the viscoe-elasticity-plasticity material constitutive equations were established.And by means of Oula difference method, the unified constitutive equations numerical solutions were also obtained. According to a cycle of strain ratio loading and by MATLAB computer simulation, the varied law of inner variables, stress and strain were found, and the validity of the viscoe-elasticity-plasticity unified constitutive models were alidated.


Deformation Behavior and Processing Map of the Nickel-based Superalloy GH4169 in the Isothermal Compression

Li Miaoquan;Wang Xiaojin;Su Shaobo;Wang Hairong

2008, 19(15):  0-1889. 

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Isothermal compression for the nickel-based superalloy GH4169 was carried out at a Thermecmaster-Z simulator, effect of the process parameters on the flow stress was investigated and the processing map was obtained in isothermal compression of the nickel-based superalloy GH4169 according to the analyses of experimental results. The research results show that the peak and steady stress significantly decreases with an increasing of the deformation temperature and a decreasing of the strain rate in the high temperature deformation of the nickel-based superalloy GH4169.The processing map was drawn from the experimental data. From the processing map of nickel-based superalloy GH4169, three unstable regions are in the following: the first is as 970~1030℃ of deformation temperature and 10.0~50.0s^-1 of strain rate, the second is as 930~940℃ of deformation temperature and 0.15~7.0s^-1 of strain rate, and the third is as 930~960℃ of deformation temperature and 7.0~50.0s^-1 of strain rate.

Simulation of Unsteady State Rolling Processes by Thermal-mechanical 
Coupled Rigid-plastic Finite Element Methods

Deng Hua;Duan Jianhui;Huang Ping;Li Hanxiong

2008, 19(15):  0-1889. 

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The biting stage of the strip rolling was simulated by using the three-dimensional large deformation thermo-mechanical coupled rigid-plastic finite element methods. The conditions in simulation were consistent with those in practical rolling processes. The simulated result was compared with the real process data, which shows that the method used herein to simulate the unsteady rolling state is practicable and reliable. Finally, the roll force distribution and the rolled piece deformation in the bite stage were studied and the rolled piece temperature influence on strip-head bending was analyzed. 

Development of Simulation and Real Time Control Platform for Fuel Cell Powertrain

Jin Zhenhua;Ouyang Minggao;Lu Qingchun;Gao Dawei

2008, 19(15):  0-1769. 

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Based on virtual instrument development workbench, simulation and real time control system for fuel cell powertrian was developed and a model based controller development platform was constructed. Sub-systems of the powertrain were modeled and simulation software was developed with LabVIEW Simulation module. Real time control system was constructed with embedded PC and LabVIEW real time module. Application of the platform shows the system works well.

Development of Mechanical Self-leveling Device for Vehicle Height

Cao Min;Wang Yibin;Yu Fan

2008, 19(15):  0-1889. 

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In view of the respective defects of existing self-leveling device for vehicle height,taking the rear independent suspension of a certain light bus as the development subject,a mechanical self-leveling device for vehicle height was innovative-designed,trial-produced and experimental-validated.To compare the performance of self-leveling suspension with that of common suspension,the time and frequency domain analytical methods were adopted to model,simulate and analyze for vehicle suspensions under the conditions of random and pulse road.Based on above experimental validation and simulation analysis,the main characteristics of self-leveling vehicle suspension are deduced preliminarily.