基于水平集方法的产品异构模型融合研究*

复杂产品设计往往涉及多个CAD/CAE系统,不同系统在几何模型构建、表达和存储等方面存在异构性,导致系统间数据和信息难以融合集成,降低了复杂产品的设计与开发效率。为了实现异构CAD/CAE模型语义信息和几何特征的融合,提出基于水平集方法的产品异构模型融合方法。构建了基于模型距离场的体素化模型,给出了体素化模型的可视表达方法,建立了距离场交、差和并集操作函数与产品造型特征复制、提取和识别的映射关系,建立了构造速度场操作函数和形位误差信息、高级语义信息和局部特征信息融合的映射关系,实现了产品异构模型的信息融合。通过复杂汽轮机叶片模型形位误差和高级语义信息融合试验,证明了方法在异构CAD/CAE系统信息集成方面的有效性和实用性。     

面向CAD系统的连续体结构形状与拓扑优化

针对当前连续体结构优化所面临的有限元模型与CAD模型转换困难,产品设计意图和结构工艺在优化过程中难以保持等问题,研究了面向CAD系统的连续体结构形状与拓扑优化方法。通过分析CAD几何表达和CAE网格划分特点,采用欧拉网格和扩展有限元法,建立面向结构优化的CAD/CAE模型融合机制;而后基于连续体物质导数,推导了CAD直接建模操作敏度,驱动CAD实体模型进行结构形状与拓扑优化。在此基础上,针对操作敏度量纲不一致问题,采用速度场均匀化方法,修正操作敏度,以提高优化收敛效率。通过三维CAD实体模型结构优化实例,验证了上述方法的可行性和求解效率。     

A CAD/CAE-integrated injection mold design system for plastic products

Mold design is a knowledge-intensive process. This paper describes a knowledge-based oriented, parametric, modular and feature-based integrated computer-aided design/computer-aided engineering (CAD/CAE) system for mold design. Development of CAx systems for numerical simulation of plastic injection molding and mold design has opened new possibilities of product analysis during the mold design. The proposed system integrates Pro/ENGINEER system with the specially developed module for the calculation of injection molding parameters, mold design, and selection of mold elements. The system interface uses parametric and CAD/CAE feature-based database to streamline the process of design, editing, and reviewing. Also presented are general structure and part of output results from the proposed CAD/CAE-integrated injection mold design system.     

PDM 在空间光学仪器虚拟产品研制开发中的应用研究

论述了在运用CAD/CAE/CAM技术研制开发空间光学仪器虚拟产品时,产品数据管理(PDM)的应用与特点,及PDM在企业产品设计管理中的应用。     

Application of an integrated CAD/CAE/CAM system for stamping dies for automobiles

The globalization and competition in the automobile industry makes it necessary to reduce the time spent on product development. Therefore, computer aided product development has become one of the most important techniques in the automobile industry. According to the concurrent engineering concept, an integrated CAD/CAE/CAM system for automobile stamping die development is established. The system is based on 3D surface construction CAD software STRIM, CAD/CAE software CATIA, stamping formability analysis software DYNAFORM, CAM software CADCEUS, a stamping design knowledge-based system, and a product database. This paper uses the development of trunk lid outer panels as an example to showcase the power of the system, in which the different development stages can be performed simultaneously. The system can greatly reduce the development time and cost, improve the product quality, and push products into the market in a relatively short time.     

基于UG的SF32601型自卸车运动学分析与仿真

在进行CAE分析时,一般是在CAD软件中建立产品模型,然后通过中间格式的转换导入CAE软件中进行CAE分析,产品的CAD数据可能会丢失或产生错误.UG的运动分析模块内嵌功能强大的ADAMS的求解器,完全满足整车运动学分析与仿真的要求.笔者以UG的运动分析模块为平台,在建立整车运动学模型后,对模型进行了运动学仿真及干涉检查,为企业的技改提供依据。     

网络制造环境下注塑模CAD/CAE系统集成的研究与实现

分析网络环境下的注塑模CAD/CAE协同工作流程,结合网络化制造和注塑成型CAE系统的特点和发展过程,提出基于Internet的解决方案。为实现CAD、CAE的协同工作,开发基于协同工作流管理的网络服务系统,实现CAD/CAE数据传输、工艺参数配置以及分析结果显示的系统集成。同时,提出基于W eb Services的解决方案,提出采用标准化、更开放的网络信息集成平台,以期推动注塑模CAD/CAE等数字化制造技术在网络环境下的应用和发展。     

Product data model for PLM system

Product lifecycle management (PLM) is a new business strategy for enterprise’s product R&D. A PLM system holds and maintaining the integrity of the product data produced throughout its entire lifecycle. There is, therefore, a need to build a safe and effective product data model to support PLM system. The paper proposes a domain-based product data model for PLM. The domain modeling method is introduced, including the domain concept and its defining standard along the product evolution process. The product data model in every domain is explained, and the mapping rules among these models are discussed. Mapped successively among these models, product data can be successfully realized the dynamic evolution and the historical traceability in PLM system.     

A task-oriented modular and agent-based collaborative design mechanism for distributed product development

The rapid expansion of enterprises makes product collaborative design （PCD） a critical issue under the distributed heterogeneous environment, but as the collaborative task of large-scale network becomes more complicated, neither unified task decomposition and allocation methodology nor Agent-based network management platform can satisfy the increasing demands. In this paper, to meet requirements of PCD for distributed product development, a collaborative design mechanism based on the thought of modularity and the Agent technology is presented. First, the top-down 4-tier process model based on task-oriented modular and Agent is constructed for PCD after analyzing the mapping relationships between requirements and functions in the collaborative design. Second, on basis of sub-task decomposition for PCD based on a mixed method, the mathematic model of task-oriented modular based on multi-objective optimization is established to maximize the module cohesion degree and minimize the module coupling degree, while considering the module executable degree as a restriction. The mathematic model is optimized and simulated by the modified PSO, and the decomposed modules are obtained. Finally, the Agent structure model for collaborative design is put forward, and the optimism matching Agents are selected by using similarity algorithm to implement different task-modules by the integrated reasoning and decision-making mechanism with the behavioral model of collaborative design Agents. With the results of experimental studies for automobile collaborative design, the feasibility and efficiency of this methodology of task-oriented modular and Agent-based collaborative design in the distributed heterogeneous environment are verified. On this basis, an integrative automobile collaborative R＆D platform is developed. This research provides an effective platform for automobile manufacturing enterprises to achieve PCD, and helps to promote product numeralization collaborative R＆D and management development.     

逆向工程集成数据处理系统

在分析研究集成逆向工程系统的特点、关键技术及实现方法的基础上，提出了一种基于商品化CAD／CAE／CAM系统，通过一数据转换器建立集成逆向工程系统的方法，其组成框架包括测量路径规划、数据处理、基准重建、格式及代码转换、CAD／CAE／CAM系统等。根据下游的应用需求。操作者可以选择不同实物测量方式、路径规划和采样点。在完成测量数据的除噪、光滑、对齐、分块和分层后。测量数据可以以IGES格式或系统要求的格式输入CAD系统进行模型重建，建立CAD模型；也可选择直接生成数控代码和STL文件。这种集成方式能提高测量及模型重建的效率。适应不同的应用需求。并能充分利用成熟的CAD／CAE／CAM系统的功能，缩短产品的开发周期。具有柔性及灵活的特点．已成功应用于实践。     

冷挤压工艺规划的发展及原型系统研究

介绍冷挤压工艺规划的研究现状,分析其发展趋势,提出一基于特征的集成ＣＡＤ／ＣＡＰＰ＝ＣＡＥ和优化技术的冷挤压工艺规划原型系统,并对基于特征的产品模型建立、可行性分析、工艺规划和工艺评价及优化等关键技术进行分析。原型系统的建立为实现集成ＣＡＤ／ＣＡＰＰ／ＣＡＥ和优化技术的冷挤压工艺规划系统奠定了基础。     

数字化设计技术在雷达机柜设计中的应用

叙述了雷达机柜现代化设计方法。它是基于计算机技术及网络平台,采用系统设计和并行设计的多学科综合设计思想,运用Top—down建模方式和模块化方式相结合进行CAD设计,根据实际工况,利用CAE软件进行力学及热分析,达到验证和优化CAD设计目的,实现产品开发的全数字化过程。雷达机柜的数字化设计包括三维几何模型设计、产品造型设计、仿真设计等,PDM对所有设计数据进行存储和管理。     

Feature-based non-manifold modeling system to integrate design and analysis of injection molding products

Current CAE systems used for both the simulation of the injection molding process and the structural analysis of plastic parts accept solid models as geometric input. However, abstract models composed of sheets and wireframes are still used by CAE systems to carry out more analyses more efficiently. Therefore, to obtain an adequate abstract model, designers often have to simplify and idealize a detailed model of a part to a specific level of detail and/or abstraction. For such a process, we developed a feature-based design system based on a non-manifold modeling kernel supporting feature-based multi-resolution and multi-abstraction modeling capabilities. In this system, the geometric models for the CAD and CAE systems are merged into a single master model in a non-manifold topological representation, and then, for a given level of detail and abstraction, a simplified solid or non-manifold model is extracted immediately for an analysis. For a design change, the design and analysis models are modified simultaneously. As a result, this feature-based design system is able to provide a more integrated environment for the design and analysis of plastic injection molding parts. This paper was recommended for publication in revised form by Associate Editor Tae Hee Lee Sang Hun Lee received his B.S., M.S., and Ph. D. degrees in Mechanical Design and Production Engineering from Seoul National University, Korea, in 1986, 1988, and 1993, respectively. Dr. Lee is currently a Professor at the School of Mechanical and Automotive Engineering at Kookmin University in Seoul, Korea. His research interests include CAD/ CAM, human-centered design and engineering, digital human modeling and simulation, computer-aided automotive design and manufacturing., and computer-aided tooling design.     

二维图像的光亮度重构实体几何模型的神经网络法

三维表面重建技术具有广泛的应用前景，由二维图像的光亮度重构实体几何模型是工业制造中迫切需要研究的课题之一。本文给出了一种基于BP神经网络的新型反射模型，用于三维实体几何模型的恢复与重建，它是基于兰伯特(Lambertian)反射模型的改进算法，这一造型手段可用于CAD/CAE/CAM系统中，使得重建出的三维模型可以参与造型系统实体的基本运算和操作，共同推动CAD/CAE/CAM在制造业信息化领域的技术进步。从实例表明该算法较传统的算法更快和更精确。     

基于逆向工程的空调遥控器三维模型设计研究

针对市场对家电产品开发周期日益苛刻的需求,为满足家电产品快速开发,快速更新的需要,以空调遥控器外形三维模型重建与再设计为例,从遥控器外形点云数据的快速测量、点云数据的处理、点云几何拓扑结构分析、主辅曲面重建以及结合新产品开发需求再设计遥控器三维模型结构等方面对家电产品的快速设计进行了研究。对基于逆向工程的家电产品三维模型快速设计方法进行了归纳,提出一种正、逆向设计相结合的产品三维模型快速设计方法。研究结果表明,基于逆向工程技术的再设计方法,有利于提高家电产品设计效率,为家电类产品的开发提供了一种方便、快捷的手段。     

三维CAD/CAE一体化的参数化动态有限元建模

提出了一种基于CAD参数化技术与CAD／CAE一体化技术的参数化动态有限元建模方法，该方法解决了三维实体有限元建模中几何模型的描述与驱动、参数联动、模型自动更新等一系列问题，为先进的参数化有限元分析与优化设计提供了关键技术基础；阐述了三维参数化动态有限元建模方法中的若干关键技术，包括具有典型意义的基于AutoCAD／MDT二次开发环境ObjectARX的CAD／CAE集成方法、复杂三维组合曲面网格全自动生成算法、复杂三维实体的四面体网格全自动生成算法、面向对象的有限元模型描述方法，以及有限元模型的参数驱动方法等；建立了一个三维参数化形状优化设计应用原型系统。     

产品设计和工程分析集成信息模型

产品设计和工程分析的有效集成是提高产品设计质量的有力保障，本文将集成过程中所涉及到的信息分成CAD设计模型，CAE分析模型和离散模型三个部分，然后介绍采用STEP资源所设计的这三个模型的集成信息模型，最后，介绍该集成信息模型的实施，该模型不仅集成了产品工程设计过程中的设计信息，而且集成了产品工程分析过程中采用各种数值方法进行数值分析计算所涉及到的诸多信息。     

基于数字制造模式的卫生洁具制造技术研究

介绍了基于CAD／CAE／CAM／RP技术的新的卫生洁具产品快速研发技术模式，即对产品进行参数化的计算机三维设计和产品物理性能的计算机模拟，然后采用快速原型技术，快速、准确地制出陶瓷种模，再翻制工作模。新方法不但提高了产品质量，而且可缩短新产品开发周期。     

基于特征建模技术的CAD/CAE集成方法研究

采用基于特征的非流型建模技术提出了实现CAD／CAE集成系统的的新方法，方法通过建立和使用包括CAD和CAE系统中需要的全部不同类型几何模型的单一主模型，并通过选择操作实现了从主模型中同步快速提取适用于CAD的实体模型和适用于CAE的非流型模型。本方法还通过基于特征的多分辨率和多抽象建模技术实现了不同细节层的CAD模型和不同抽象层的CAE模型建立：     

CAD三维实体造型对企业产品研发能力的影响

目前，CAD的应用是一个企业产吊研发过程中必不可少的。对企业产品的研发流程以及产品研发过程中二维CAD应用存在的主要问题进行了研究，阐述了三维图形软件的应用以及CAE软件的应用对企业产品研发能力的影响。