检索结果-南通市图书馆

Acquisition and Active Navigation of Knowledge Particles throughout Product Variation Design Process

Chinese Journal of Mechanical Engineering 2009年第3期22卷 395-402页

作者： zhang shuyou XU Jinghua Mechanical Engineering Department Zhejiang University Hangzhou 310027 China

The variation design of complex products has such features as multivariate association, weak theory coupling and implicit knowledge iteration. However, present CAD soft wares are still restricted to making decisions only according to current design status in dynamic navigation which leads to the huge drain of the knowledge hidden in design process. In this paper, a method of acquisition and active navigation of knowledge particles throughout product variation design process is put forward. The multi-objective decision information model of the variation design is established via the definition of condition attribute set and decision attribute set in finite universe. The addition and retrieval of the variation semantics is achieved through bidirectional association between the transplantable structures and variation design semantics. The mapping relationships between the topology lapping geometry elements set and constraint relations set family is built by means of geometry feature analysis. The acquisition of knowledge particles is implemented by attribute reduction based on rough set theory to make multi-objective decision of variation design. The topology lapping status of transplantable substructures is known from DOF reduction. The active navigation of knowledge particles is realized through embedded event-condition-action（ECA） rules. The independent prototype system taking Alan, Charles, Ian＇s system（ACIS） as kernel has been developed to verify the proposed method by applying variation design of complex mechanical products. The test results demonstrate that the navigation decision basis can be successfully extended from static isolated design status to dynamic continuous design process so that it more flexibly adapts to the different designers and various variation design steps. It is of profound significance for enhancing system intelligence as well as improving design quality and efficiency.

关键词： variation design knowledge particles acquisition active navigation structure transplantation rough set

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Model Order Reduction for Coupled Dynamic Characterization of Torsional Micromirrors

引用

Chinese Journal of Mechanical Engineering 2011年第5期24卷 829-835页

作者： SHI Jian zhang shuyou Department of Mechanical Engineering Zhejiang University Hangzhou 310027 China

Numerical solutions could not perform rapid system-level simulation of the behavior of micro-electro-mechanical systems（MEMS） and analytic solutions for the describing partial differential equations are only available for simple *** order reduction（MOR） can extract approximate low-order model from the original large scale *** model order reduction algorithm is based on first-order system model,however,most structure mechanical MEMS systems are naturally second-order in *** the purpose of solving the above problem,a direct second-order system model order reduction approach based on Krylov subspace projection for the coupled dynamic study of electrostatic torsional micromirrors is *** block Arnoldi process is applied to create the orthonormal vectors to construct the projection matrix,which enables the extraction of the low order model from the discretized system assembled through finite element *** transfer functions of the reduced order model and the original model are expanded to demonstrate the moment-matching property of the second-order model reduction *** torsion and bending effect are included in the finite element model,and the squeeze film damping effect is considered as *** empirical method considering relative error convergence is adopted to obtain the optimal choice of the order for the reduced model.A comparison research between the full model and the reduced model is carried *** modeling accuracy and computation efficiency of the presented second-order model reduction method are confirmed by the comparison research *** research provides references for MOR of MEMS.

关键词： model order reduction torsional micromirror moment-matching

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Virtual Reality Toolkit for the Assembly of Nanotube-based Nano-electro-mechanical Systems

引用

Chinese Journal of Mechanical Engineering 2011年第1期24卷 1-11页

作者： GAO Zhan LECUYER Anatole zhang shuyou State Key Laboratory ofCAD＆CG Zhejiang University Hangzhou 310027 China School of Computer Science and Technology Nantong University Nantong 226019 China BUNRAKU Group INRIA Campus University de Beaulieu Rennes 35042 France

Nano assembly and manipulation technologies are the basis for nano-electro-mechanical systems（NEMS）. Atomic force microscope（AFM） is widely used to manipulate nanotubes to assemble NEMS. Manipulating nanotubes with AFM is a challenging and difficult task. One of the major reasons is the deficiency of visual information during the manipulation process. To address these difficulties, this research aims to put forward novel virtual tools and assembly strategies to improve the efficiency, accuracy and ease of the assembly process of NEMS. This paper begins by the discussion of the principles and implementation of a virtual nano-assembly simulator, which serves as a benchmark to test the proposed NEMS assembly techniques and virtual tools. Then, a general framework of nanotube-based NEMS assembly is proposed. Several nano-assembly strategies and virtual tools, such as automated path planning for NEMS assembly, a four-step scheme of nanotube manipulation, virtual fixtures for assembly finalization and safe manipulation, are introduced. These virtual tools and methods are experimented for justification. An assembly task of moderate complexity was performed in our virtual nano-assembly simulator with and without the help of the proposed toolkit. Experimental results suggest that the proposed methods tend to greatly enhance the efficiency and accuracy of nanotube-based NEMS assembly. In general, the proposed virtual reality toolkit not only ensures the safety, but also enhances the accuracy and efficiency of the assembly of nanotube-based NEMS.

关键词： virtual reality nano-assembly nano-electro-mechanical systems haptic feedback

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Structural Scheme Optimization Design for the Stationary Platen of a Precision Plastic Injection Molding Machine

引用

Chinese Journal of Mechanical Engineering 2014年第4期27卷 714-721页

作者： REN Bin zhang shuyou TAN Jianrong State Key Laboratory of Fluid Power Transmission and Control Zhejiang University Department of Civil and Architectural Engineering City University of Hong Kong

The current development of precision plastic injection molding machines mainly focuses on how to save material and improve precision, but the two aims contradict each other. For a clamp unit, clamping precision improving depends on the design quality of the stationary platen. Compared with the parametric design of stationary platen, structural scheme design could obtain the optimization model with double objectives and multi-constraints. In this paper, a SE-160 precision plastic injection molding machine with 1600 kN clamping force is selected as the subject in the case study. During the motion of mold closing and opening, the stationary platen of SE-160 is subjected to a cyclic loading, which would cause the fatigue rupture of the tie bars in periodically long term operations. In order to reduce the deflection of the stationary platen, the FEA method is introduced to optimize the structure of the stationary platen. Firstly, an optimal topology model is established by variable density method. Then, structural topology optimizations of the stationary platen are done with the removable material from 50%, 60% to 70%. Secondly, the other two recommended optimization schemes are given and compared with the original structure. The result of performances comparison shows that the scheme II of the platen is the best one. By choosing the best alternative, the volume and the local maximal stress of the platen could be decreased, corresponding to cost-saving material and better mechanical properties. This paper proposes a structural optimization design scheme, which can save the material as well as improve the clamping precision of the precision plastic injection molding machine.

关键词： finite element analysis injection molding machine stationary platen topology optimization

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Reconfigurable Modeling Technology of Similar-structure Products Configuration Design

引用

Chinese Journal of Mechanical Engineering 2013年第1期26卷 189-196页

作者： QIU Lemiao REN Bin zhang shuyou XU Jian The State Key Lab of Fluid Power Transmission and Control Zhejiang University

The product configuration modeling is a key technology to realize configuration design. Most of the researches were mainly conducted focusing on how to establish a product configuration model, but were short of the consideration about the application scope and dynamic change features. In this paper, the reconfigurable modeling technology of similar-structure products configuration design is studied to enhance the generality and diversity of product configuration models, and to facilitate the dynamic upgrade of configuration models. The configuration components of products with similar structures are divided into sharable configuration components, essential configuration components and optional configuration components, so the construction of reconfigurable model of configuration design can be converted into the set operation of configuration components. The horizontal adjusting reconstruction of configuration model is carried out through the adding, replacing and deleting of configuration components, the vertical adjusting reconstruction of configuration model is carried out through the parametric deformation of configuration components, and the variable topological configuration model reconstruction can be realized through the transformation of partial structure of configuration components. Finally, NC machine products are used as an example to analyze and verify the reconfigurable modeling technology of products with similar structures. The speed of NC machine configuration design is found to be improved, and the number of NC machine configuration design models is decreased. And the reconfigurable design system of NC machine products is developed. The proposed modeling technology provides references for the processes, methods and steps of model reconstruction.

关键词： similar-structure products configuration component product configuration model reconstruction

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

REVERSE DESIGN APPROACH FOR MECHANISM TRAJECTORY BASED ON CODE-CHAINS MATCHING

引用

Chinese Journal of Mechanical Engineering 2007年第3期20卷 86-90页

作者： zhang shuyou YI Guodong XU Xiaofeng State Key Laboratory of CAD＆CG Zhejiang University Hangzhou 310027 China

Aiming at the problem of reverse-design of mechanism, a method based on the matching of trajectory code-chains is presented. The motion trajectory of mechanism is described with code-chain, which is normalized to simplify the operation of geometric transformation. The geometric transforma-tion formulas of scale, mirror and rotation for trajectory code-chain are defined, and the reverse de-sign for mechanism trajectory is realized through the analysis and solution of similarity matching between the desired trajectory and the predefined trajectory. The algorithm program and prototype system of reverse design for mechanism trajectory are developed. Application samples show that the method can break the restriction of trajectory patterns in matching, meet the demand of partial match-ing, and overcome the influence of geometric transformation of trajectory on the reverse design for mechanism.

关键词： Trajectory Code-chain Similarity matching Reverse-design

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

MODELING METHOD FOR PRODUCT STRUCTURE MAPPING BASED ON REVERSE SOLVING OF LOCUS AND MOTION

引用

Chinese Journal of Mechanical Engineering 2007年第5期20卷 114-119页

作者： zhang shuyou YI Guodong XU Xiaofeng State Key Laboratory of CAD＆CG Zhejiang University Hangzhou 310027 China

Aiming at the problem of structure design in reverse-design of mechanism, a structure mapping method based on reverse solving of locus and motion （RSLM） is presented. The mechanism scheme meeting the requirements of geometric and structural features is obtained through RSLM. The element instance subsets related to component are established based on the element type mapping, pair structure type mapping and design knowledge mapping between components and elements layer by layer. The assembly position mapping of elements is established based on the topological structure information of mechanism scheme, and the product modeling of structure mapping is realized. The algorithm program and prototype system of product structure mapping based on RSLM are developed. Application samples show that the method implements the integration of scheme design, assembly design and structure design, and modeling for product structure mapping based on RSLM. The feasibility of assembly is analyzed in scheme design that contributes to reducing the design error, and raising the design efficiency and quality.

关键词： Reverse solving Mapping Mechanism Assembly Modeling

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Disassemblability Modeling Technology of Configurable Product Based on Disassembly Constraint Relation Weighted Design Structure Matrix(DSM)

引用

Chinese Journal of Mechanical Engineering 2014年第3期27卷 511-519页

作者： QIU Lemiao LIU Xiaojian zhang shuyou SUN Liangfeng The State Key Lab of Fluid Power Transmission and Control Zhejiang University

The current research of configurable product disassemblability focuses on disassemblability evaluation and disassembly sequence planning. Little work has been done on quantitative analysis of configurable product disassemblability. The disassemblability modeling technology for configurable product based on disassembly constraint relation weighted design structure matrix （DSM） is proposed. Major factors affecting the disassemblability of configurable product are analyzed, and the disassembling degrees between components in configurable product are obtained by calculating disassembly entropies such as joint type, joint quantity, disassembly path, disassembly accessibility and material compatibility. The disassembly constraint relation weighted DSM of configurable product is constructed and configuration modules are formed by matrix decomposition and tearing operations. The disassembly constraint relation in configuration modules is strong coupling, and the disassembly constraint relation between modules is weak coupling, and the disassemblability configuration model is constructed based on configuration module. Finally, taking a hydraulic forging press as an example, the decomposed weak coupling components are used as configuration modules alone, components with a strong coupling are aggregated into configuration modules, and the disassembly sequence of components inside configuration modules is optimized by tearing operation. A disassemblability configuration model of the hydraulic forging press is constructed. By researching the disassemblability modeling technology of product configuration design based on disassembly constraint relation weighted DSM, the disassembly property in maintenance, recycling and reuse of configurable product are optimized.

关键词： disassemblability modeling disassembly entropy disassembling degree weighted DSM product configuration model

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Metamorphic Manipulating Mechanism Design for MCCB Using Index Reduced Iteration

引用

Chinese Journal of Mechanical Engineering 2013年第2期26卷 232-241页

作者： XU Jinghua zhang shuyou ZHAO Zhen LIN Xiaoxia State Key Laboratory of Fluid Power Transmission and Control Zhejiang University

The present research on moulded case circuit breaker（MCCB） focuses on the enhancement of current-limiting interrupting performance during short circuit, overload, under voltage and phase failure, involving electrics, magnetic, mechanics, thermal, material, friction, arc extinguishing, impact vibration, skin effect, etc. The rigid-flexible coupling of the parts and components of the metamorphic manipulating mechanism in multi-fields leads to the non-rigid, high frequency, high damping, singularity of the Euler-Lagrange equations which represents the multi-body dynamics. The small step iteration which is used for obtaining the instantaneous and short time critical interrupting performance of metamorphic mechanism appears inaccuracy. It is difficult to realize top-down design by existing CAD systems. Therefore, a metamorphic manipulating mechanism design method for MCCB using index reduced iteration（IRI） is put forward. The metamorphic manipulating mechanism of MCCB is decomposed into three mechanisms： main switch connector mechanism, electromagnet-drawbar-jump buckle mechanism, and bimetallic strip-drawbar mechanism, which is respectively described by electro-dynamic force, electromagnet force, and bimetallic strip force. The dummy part（virtual rigid） without moment of inertia and mass is employed as intermediate to join the flexible body and rigid body. The model of rigid-flexible coupling metamorphic mechanism multi-body dynamics is built. The differential algebraic equations（DAEs） of the multibody dynamics model are converted to pure ordinary differential equations（ODEs） by coordinate partition. Order reduced integration with multi-step and variable step-size is preceded based on IRI. The non-linear algebraic equations are solved in each integration step by Newton-Rapson iteration. There is no ill-condition and singularity of Jacobian matrix when step size reduces to zero. The independent prototype design system using ACIS R13, HOOPS V11.0 and Visual C＋＋.NET 2003 h

关键词： index reduced iteration (IRI) moulded case circuit breaker (MCCB) metamorphic manipulating mechanism Euler-Lagrange equations rigid-flexible coupling multi-body dynamics current interrupting simulation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

层次多叉树映射布尔体廓后验误差的自适应层切

引用

浙江大学学报（工学版） 2024年第4期58卷 748-760页

作者：郭洪帅张树有伊国栋刘晓健谭建荣浙江大学流体动力基础件与机电系统全国重点实验室浙江杭州310027 浙江大学宁波科创中心浙江宁波315100

在给定构建方向下,层切厚度影响熔融沉积成型零件表面的阶梯效应,层切轮廓及其层次关系是路径规划的研究基础.为此,提出基于布尔体廓运算的自适应层切方法,在零件模型不同高度层切面上构建局部轮廓拓扑并计算内核域,根据内核点连线与轮... 详细信息

在给定构建方向下,层切厚度影响熔融沉积成型零件表面的阶梯效应,层切轮廓及其层次关系是路径规划的研究基础.为此,提出基于布尔体廓运算的自适应层切方法,在零件模型不同高度层切面上构建局部轮廓拓扑并计算内核域,根据内核点连线与轮廓环的交点,将轮廓环数据映射到一维坐标轴,基于拓扑映射判定轮廓环层次关系.建立层次关系多叉树,以树高映射体廓特征变化的布尔运算,根据层变阈值设计自适应层厚,通过体廓后验误差估计任意层厚的体积误差,验证自适应层切的有效性.实例打印及不同自适应层切方法对比结果表明,采用体廓后验误差计算的层切体积误差精度比牙尖高度法的更高;通过控制体廓特征部位的层厚来减小体积误差,有助于提高模型特征部位的表面成型精度.

关键词：熔融沉积成型自适应层切拓扑映射体积误差层次多叉树体廓后验误差

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：