NURBS曲线曲面的构形原理及其在产品造型中的应用

本文介绍了NURBS曲线、曲面的数学表达,给出了NURBS曲线和曲面的构形原理,在此基础上,推导了过滤曲面,进而获得了产品造型所要求的曲面。实践表明,应用NURBS曲面,使产品造型设计者能随心所欲地实现自己的设计意图。     

基于Pro/engineer的折叠夹板注塑模虚拟装配及模流仿真

利用Pro／engineer对折叠夹板进行产品及注塑模的参数化设计及虚拟装配。检测模具开模时的干涉情况;同时,仿真注射时的模流过程,实现在设计模具时就确切了解塑料在型腔中的充填和流动情况,预测折叠夹板产品质量,从而优化了模具的设计流程,减少了设计周期。     

产品复杂曲面人机工程学设计研究

对产品形态设计中复杂曲面的人机工程学性能的设计问题进行了分析,研究了产品曲面人机性能设计的解决方案,应用遗传算法工具实现了对复杂曲面形态解方案的随机搜索以及通过程序进行自动评价与选择的机制,建立了基于Unigraphics造型平台的曲面人机设计过程机制与原型系统。     

基于Protoolkit的圆柱螺旋齿轮的精确三维参数化建模

在CAD/CAM/CAE中,机械产品的三维建模是基础,其精确程度和质量决定着设计、分析、制造等后续过程的质量。文中讨论了圆柱齿轮中的一类圆柱螺旋齿轮的齿廓曲面的精确表达,在三维造型软件Pro/Engineer中的生成方法以及在Pro/Engineer与C语言的接口Protoolkit中,圆柱螺旋齿轮上的形状结构特征在Pro/Engineer中的表达、操作、处理函数的功能和应用开发方法。并以此为例设计了一个圆柱螺旋齿轮的三维参数化设计系统。     

电视机屏幕高次方程曲面的精确绘制

在进行产品设计时,经常要用到曲线、曲面的绘制。高次方程表达的曲面如Z=f (x, y)对于三维绘图软件往往难于实现。介绍了一种快速、精确地绘制高次方程曲面的方法,即使用数学软件MATLAB来进行点阵数据的计算,然后将点阵数据保存到记事本当中,并转化为Pro/E可以接受的*.ibl形式,在Pro/E中生成曲面并进行曲面的优化,从而拓宽了Pro/E软件在曲面设计中的应用。     

基于Pro／ENGINEER的蓝牙耳机逆向造型设计

一、引言 由于曲面产品造型复杂、难以直接确定其各曲线的连接点等原因,在对成型产品进行修改的过程中,通过对产品模型进行逆向扫描,完成产品模具的逆向造型设计,可以大大加快产品的研发速度,尤其对于复杂曲面的物件来说,经济效益更是明显。模具逆向工程技术是利用计算机辅助测量技术与CAD／CAM技术,实现实物扫描、几何建模和曲面加工体化,     

汽车车身逆向工程设计关键技术及应用

逆向工程设计方法是汽车车身设计过程中的一个重要环节,也是一种快速设计的工程方法。逆向工程设计主要包括如下过程：三维测量获得点云数据、数据处理、特征提取、曲面重构和曲面评价等。逆向设计并不是简单地复制,而是要在逆向过程中增加一些特征要素,以设计出工艺性更好、质量更高的产品的过程。该文主要探讨汽车车身逆向设计的关键技术和技术特点。     

用Imageware进行车身A级曲面设计

本文介绍了A级曲面的技术要求和应用在车身上的设计准则以及使用Imageware进行A级曲面设计的关键点.通过车身轮舱的A级曲面设计实例,证明了Imageware在车身高品质曲面设计中巨大的发展潜力.     

汽车前轴零件三维参数化实体建模技术的研究

一、前言CAD/CAM技术的发展经历了四个阶段：曲面造型技术、实体造型技术、参数化技术和变量化技术。每次新技术的出现都促进了设计技术的提高和制造技术的更新。当前,CAD/CAM技术正朝着更加智能化和集成化的方向发展。在我国,虚拟现实技术、三维造型技术、参数化设计技术等新概念正逐步渗透到传统的设计与制造过程中,改变着人们的设计思路和行为模式,推动着工程技术的不断发展。由于产品的有限元分析、模具设计、工艺设计和NC代码生成等设计环节均建立在产品的三维模型基础上,因而快速、准确地建立产品的三维模型是产品设计过程…     

过测地线的优化曲面设计

给定一条曲线,构造以其为测地线的曲面,这是服装鞋帽类产品的设计/制造业中的一个现实课题.已有研究结果是构造出以给定曲线为公共测地线的曲面束,然后用拟合数据点的方法来确定最终曲面.这种通用方法受到曲面参数及其表示方法的影响,且没有对曲面的光顺程度加以考虑.从服装材料的特性和设计思想出发,提出一种利用能量优化来确定最终曲面的新方法.通过改变曲面表示形式和引入能量函数,方便而有效地确定了过给定测地线的一张优化曲面.给出了在插值拟合等约束条件下的相应算法.实例表明,所给算法很好地模拟了成衣的光顺设计与加工,在计算机辅助设计/制造(CAD/CAM)中富有应用价值.     

基于组件的典型零部件快速设计系统的开发

文章提出了一种基于组件技术的典型零部件快速设计系统的开发技术,通过开发基于组件的典型零部件设计校核模块,建立基于XML技术的典型零部件的模型库及其管理模块,同时为适应工程图的要求,开发了国标符号程序库,达到了跨多种CAD平台的软件及设计资源复用的需要。并以Pro/E平台为例,通过API接口组件的开发,实现了该平台下的典型零部件的设计计算、造型、生成符合国标的工程图,极大地提高了设计效率。     

面向机器人装配设计与规划的集成框架

本文针对面向机器人装配的产品设计与装配规划中的关键问题,分析实际产品设计与 装配规划的一般过程,提出了将面向机器人装配的产品设计与装配规划进行系统集成的框架 ,并对系统的各个模块的功能和实现作了研究探讨,通过在工程实践中的应用验证了其正确 性和有效性．     

MSC SimDesigner在产品设计中的作用

MSC SimDesigner是面向设计工程师开发的仿真平台,借助它可以使产品设计流程中的结构设计和工程分析更紧密地结合在一起,从而减少设计失误. 本文通过示例展示基于该仿真平台的创新流程所蕴含的巨大优势.     

Reuse in Command-and-Control Systems

Rockwell International's Command-and-Control Systems Division, assisted by the Software Productivity Consortium, initiated a pilot project to evaluate the applicability of SPC's Synthesis methodology. Synthesis is an approach based on domain-specific reuse, by which an organization can standardize its perceptions of customers' needs and effective solutions. We present CCSD's experience to date using Synthesis. Our application of Synthesis has resulted in a partially automated environment that supports the specification of a communications-control and -management system and the generation of corresponding software requirements, design, and code. A domain-specific notation, created by the project, lets an engineer describe one of these systems in terms of high-level requirements and engineering decisions. The engineer can then generate a product by mechanically selecting, adapting, and composing the relevant reusable components based on those decisions. We have used this environment to create parts of two products, and we are now using it on a CCSD project     

Developments of CAD in civil engineering reviewed

Substantial progress has been made during the past decade in making the computer an effective analytical tool for the design engineer. However more recent development has concentrated on various features of a design offices final product. These areas comprise production of construction drawings, interactive graphics, colour graphics, pre-and post-processing of input and output data, linking analysis programs to modular design programs to provide a rapid transfer of design to the latest code requirement, use of microcomputers and personal computers. There is also significant software development for site management, cost analysis, general administration and documentation related to construction. This takes advantage of the availability of cheaper hardware which can communicate with other computers elsewhere in a network. User interaction facilities are being built into programs which allow the engineer to concentrate on design decisions. This paper reviews the developments during the last two-three years in CAD in Civil Engineering.     

A feasible approach to the integration of CAD and CAPP

Although current CAD systems are declared to be feature-based, in fact, the so-called feature is just a modeling macro or menu name such as Protrusion, Revolution, Cutout, Block, etc., instead of a design feature or manufacturing feature in accordance with engineering practice. Consequently, product model data insufficiency and incompatibility between varieties of application systems are still the major barriers to system integration, especially the integration of design and process planning. This paper proposes a practical solution for a bi-directional integration of CAD and CAPP on the platform of commercial CAD systems. The key techniques such as feature recognition and conversion, feature parameter and constraint extraction, feature tree reconstruction, technical information processing, process planning, automatic process drawing marking and 3D material stock CAD model generating are discussed. And the extracted features and their related technical information and knowledge are encapsulated together with the geometry-oriented CAD model to form an integrated product information model to facilitate effective integration with the downstream activities. The integrated CAD/CAPP system is implemented on a commercial CAD package, UGS/SolidEdge. A case study and industry implementation illustrate the feasibility of the approach proposed.     

Image Processing to Automate Mesh Generation

Finite element modeling is now a standard approach used in the industry to minimize costly trials and help reduce the overall lead time in product and process design. However, building surface/solid models defining the product shape and generating finite element meshes for analyses still require a significant amount of the engineers’ time. In this paper, we present a new method for automatically generating a finite element mesh directly from bitmap images obtained from an artist’s concept of a label for an embossed aluminum beverage can, and demonstrate its application towards the building of tooling mesh models used in the modeling of the embossing process. This approach completely eliminates the need for creating a surface/solid model, thus resulting in a dramatic reduction in the time required for process design.     

Shape mining: A holistic data mining approach for engineering design

Although the integration of engineering data within the framework of product data management systems has been successful in the recent years, the holistic analysis (from a systems engineering perspective) of multi-disciplinary data or data based on different representations and tools is still not realized in practice. At the same time, the application of advanced data mining techniques to complete designs is very promising and bears a high potential for synergy between different teams in the development process. In this paper, we propose shape mining as a framework to combine and analyze data from engineering design across different tools and disciplines. In the first part of the paper, we introduce unstructured surface meshes as meta-design representations that enable us to apply sensitivity analysis, design concept retrieval and learning as well as methods for interaction analysis to heterogeneous engineering design data. We propose a new measure of relevance to evaluate the utility of a design concept. In the second part of the paper, we apply the formal methods to passenger car design. We combine data from different representations, design tools and methods for a holistic analysis of the resulting shapes. We visualize sensitivities and sensitive cluster centers (after feature reduction) on the car shape. Furthermore, we are able to identify conceptual design rules using tree induction and to create interaction graphs that illustrate the interrelation between spatially decoupled surface areas. Shape data mining in this paper is studied for a multi-criteria aerodynamic problem, i.e. drag force and rear lift, however, the extension to quality criteria from different disciplines is straightforward as long as the meta-design representation is still applicable.     

移情在产品设计中的诠释方式研究

理性的技术如伺获得感性的表达。是新时代、新技术下新的社会要求。文章提出移情作为一种情感化的设计方法．设计师通过对用户群的分析,将用户群以往的情感、思想、体验等融入到产品中,借助产品的形态、色彩、使用体验等实现移情,使产品成为一个有生命的个体,“由物及我,由我及物”,使用户获得愉悦的情感体验,从而提升产品的认同感。