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DEFICIENT INFORMATION MODELING OF MECHANICAL PRODUCTS FOR CONCEPTUAL SHAPE DESIGN

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Chinese Journal of Mechanical Engineering 2002年第1期15卷 1-5,26页

作者： Liu Jihong Shu Huilin cad Center，Huazhong University of Science and Technology，Wuhan 430074，China cad Center Huazhong University of Science and Technology Wuhan 430074

In allusion to the deficient feature of product information in conceptualdesign, a framework of deficient information modeling for conceptual shape design is put forward,which includes qualitative shape modeling (a qualitative solid model), uncertain shape modeling (anuncertain relation model) and imprecise shape modeling (an imprecise region model). In theframework, the qualitative solid model is the core, which represents qualitatively (using symbols)the conceptual shapes of mechanical products. The uncertain relation model regarding domainrelations as objects and the imprecise region model regarding domains as objects are used to dealwith the uncertain and imprecise issues respectively, which arise from qualitative shape modeling orexist in product information itself.

关键词： Conceptual shape design Qualitative solid model Spatial cognition

RESEARCH OF GUIDANCE TECHNOLOGY FOR ASSEMBLY MODELING IN VIRTUAL ENVIRONMENT

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Chinese Journal of Mechanical Engineering 2001年第2期14卷 139-143,150页

作者： Zhang Shuyou Liu Zhenyu Tan Jianrong State Key Laboratory of cad&CG,Zhejiang University 浙江大学计算机辅助设计与图形学国家重点实验室浙江

Technology of movement and knowledge guidance in virtual assembly is presented The designer can move the mechanical part precisely under the movement guidance The movement guidance is implemented based on constraint recognition and assembly degree of freedom analysis A multi hierarchy knowledge base is built to represent the assembly knowledge and information The virtual assembly system judges the requirement of the designer based on the context of design task and searches for the useful knowledge and information, which can be provided to the designer in a natural way

关键词： Virtual assembly Virtual reality Movement guidance Knowledge guidance

Co-evolutionary design of discrete structures based on the ant colony optimization

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Progress in Natural Science:Materials International 2007年第9期17卷 1082-1094页

作者： Tao Zhenwu and Xiao Renbin(cad Center,Huazhong University of Science and Technology,Wuhan 430074,China) cad Center Huazhong University of Science and Technology Wuhan 430074 China

In order to optimize the sizing and topology of discrete structures together and resist the combinatorial explosion of the solution space,a co-evolutionary design(CED)method based on ant colony optimization(ACO)for discrete structures is *** tailored ant colony optimization for the sizing of structures(TACO-SS)and the tailored ant colony optimization for the topology of structures(TACO-TS)are implemented *** analysis shows that the computation complexity of each sub-process in CED based on ACO above is polynomial and it guarantees the efficiency of this *** the parameter settings in TACO-SS and TACO-TS are discussed,the convergence history of a sub-process is studied through an instance in ***,according to the design examples of the 10-bar and 15-bar trusses under different cases,the effectiveness of the CED based on ACO is validated and the effects of the loads and the deflection constraints on the co-evolutionary design are discussed.

关键词： evolutionary design ant colony optimization sizing optimization topology optimization

RESEARCH ON THE CONSTRAINT MAPPING FROM FUNCTION TO ASSEMBLY

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Chinese Journal of Mechanical Engineering 2003年第3期16卷 305-308页

作者： Tan JianrongJi YangjianLiu ZhenyuChen HongliangYue XiaoliState Key Laboratory of cad&CG,Zhejiang University,Hangzhou 310027, China Zhejiang University State Key Laboratory of CAD&CG Hangzhou 310027

Assembly sketch is not only the visualization of abstract function, but alsothe template of detail design. Two kinds of information are needed to create assembly sketch:structure and assembly constraint. Most researches are aimed at bow to obtain Structures fromfunction, but the problem of how to obtain assembly constraint from function is ignored. Followingthe definition of assembly unit and the classification of function, a hierarchical mapping methodfrom function to assembly constraint is put forward, and the mapping method includes two steps. Thefirst step is the mapping from function to assembly semantics which is assembly expression andaccordant with engineer's design habit. The second one is the mapping from assembly semantics tobasic assembly constraints that are convenient for computer to handle. The mapping method is appliedto DDMS (design, drafting and management system) successfully.

关键词： Constraint mapping Assembly constraint Assembly design Function design

PREDICTION OF ACOUSTIC PERFORMANCE IN EXPANSION CHAMBER MUFFLERS WITH MEAN FLOW BY FINITE ELEMENT METHOD

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Chinese Journal of Mechanical Engineering 2003年第3期16卷 292-295,304页

作者： Liu YadongLi CongxinRuan XueyuNational Die & Mold cad EngineeringResearch Center,Shanghai Jiaotong University,Shanghai 200030, China Shanghai Jiaotong University National Die & Mold CAD Engineering Research Center 上海 200030

The equation of wave propagation in a circular chamber with mean flow is obtained. Computational solution based on finite element method is employed to determine the transmission loss of expansive chamber. The effect of the mean flow and geometry (length of expansion chamber and expansion ratio)on acoustic attenuation performance is discussed, the predicted values of transmission loss of expansion chamber without and with mean flow are compared with those reported in the literature and they agree well. The accuracy of the prediction of transmission loss implies that finite element approximations are applicable to a lot of practical applications.

关键词： Wave equation Finite element method Exhaust mufflers Acoustic characteristics

INTEGRATED LAYOUT DESIGN OF CELLS AND FLOW PATHS

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Chinese Journal of Mechanical Engineering 2003年第3期16卷 225-228页

作者： Li Zhihua Zhong Yifang Zhou Ji cad Center, Huazhong University of Science and Technology,Wuhan 430074, China cad Center Huazhong University of Science and Technology Wuhan 430074

The integrated layout problem in manufacturing Systems is investigated. Anintegrated model for Concurrent layout design of cells and flow paths is formulated. A hybridapproach combined an enhanced branch-and-bound algorithm with a simulated annealing scheme isproposed to solve this problem. The integrated layout method is applied to re-layout the gear pumpshop of a medium-size manufacturer of hydraulic pieces. Results show that the proposed layout methodcan concurrently provide good solutions of the cell layouts and the flow path layouts.

关键词： Facility layout Integrated layout design Material flow network Manufacturing system

A new method for designing a developable surface utilizing the surface pencil through a given curve

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Progress in Natural Science:Materials International 2008年第1期18卷 105-110页

作者： Hongyan Zhao,Guojin Wang* Department of Mathematics and State Key Laboratory of cad&CG,Zhejiang University,Hangzhou 310027,China Department of Mathematics and State Key Laboratory of cad&CG Zhejiang University Hangzhou 310027 China

This paper proposes a new method for designing a developable surface by constructing a surface pencil passing through a given curve, which is quite in accord with the practice in industry design and *** utilizing the Frenet trihedron frame,we derive the necessary and suffcient conditions to construct a developable surface through a given *** the requirements in shoemak- ing and garment-manufacture industries,we also study the special case of specifying the given curve as a *** given geodesic can be classified into three types corresponding to each type of developable *** also present the polynomial representation of the developable *** algorithm is convenient and effcient for applications in engineering.

关键词： cad/CAM Developable surface Geodesic Frenet frame

From Concepts to Consistent Object Specifications:Translation of a Domain-Oriented Feature Framework into Practice

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Journal of Computer Science & Technology 2001年第3期16卷 208-230页

作者： Harald E. Otto cad/CAM Research, University of Tokyo, 7-3-1 Hongo, Bunkyo-Ku, 113-8656 Tokyo, Japan cad/CAM Research University of Tokyo Tokyo Japan

A steady increase in consumer demands, and severe constraints from both a somewhat damaged environment and newly installed government policies, require today's product design and development to be faster and more efficient than ever before, yet utilizing even fewer resources. New holistic approaches, such as total product life cycle modeling which embraces all aspects of a product's life cycle, are current attempts to solve these problems. Within the field of product design and modeling, feature technology has proved to be one very promising solution component. Owing to the tremendous increase in information technology, to transfer from low level data processing towards knowledge modeling and information processing is about to bring a change in almost every computerized application. From this viewpoint, current problems of both feature frameworks and feature systems are analyzed in respect to static and dynamic consistency breakdowns. The analysis ranges from early stages of designing (feature) concepts to final system implementation and application. Por the first time, an integrated view is given oil approaches, solutions and practical experience, with feature concepts and structures, providing both a feature framework and its implementation with sufficient system architecture and computational power to master a fair number of known consistency breakdowns, while providing for robust contexts for feature semantics and integrated models. Within today's heavy use of information technology these are pre-requisites if the full potential of feature technology is to be successfully translated into practice.

关键词： framework integration feature semantics conceptual structures model consistency

THE LIMITING CASE OF THIELE'S INTERPOLATING CONTINUED FRACTION EXPANSION

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Journal of Computational Mathematics 2001年第4期19卷 433-444页

作者： Jie-qing Tan (Institute of Applied Mathematics, College of Science and cad/CG Division College of Computer & Information Hefei, University of Technology, Hefei 230009, China) 中国科学技术大学安徽合肥 230009

By means of the determinantal formulae for inverse and reciprocal differences with coincident data points, the limiting case of Thiele's interpolating continued fraction expansion is studied in this paper and given numerical example shows that the limiting Thiele's continued fraction expansion can be determined once for all instead of carrying out computations for each step to obtain each convergent as done in [3].

关键词： Continued fraction Inverse difference Reciprocal difference Expansion.