与设备无关的CAD／CAM软件生成环境

程序分级交互绘图系统ＰＨＩＧＳ（Ｐｒｏｇｒａｍｍｅｒ′ｓＨｉｅａｒｃｈｉｃａｌＩｎｔｅｒａｃｔｉｖｅＧｒａｐｈｉｃＳｙｓｔｅｍ）是一种有用的ＣＡＤ／ＣＡＭ软件生成工具。本文叙述一个应用程序设计环境，ＣＡＤＭＡＤＥ（ＣｏｍｐｕｔｅｒＡｉｄｅｄＤｅｓｉｇｎａｎｄＭａｎｕｆａｃｔｕｒｉｎｇＡｐｐｌｉｃａｔｉｏｎｓＤｅｖｅｌｏｐｍｅｎｔＥｎｖｉｒｏｍｍｅｎｔ）它被设计成为一个标准支持软件的框架，帮助ＣＡＤ／ＣＡＭ程序员去产生一个新的用户ＣＡＤ／ＣＡＭ应用软件。ＣＡＤＭＡＤＥ不是对软件的一种描述，而是提出一套生成应用程序设计环境所必需的规则和风格。     

船舶舱室布置CAD实用方法研究

介绍微机船舶舱室布置ＣＡＤ软件ＥＳＩ－ＣＡＤＣＡＢＩＮ。该系统在ＤＯＳ及ＡｕｔｏＬＩＳＰ语言的基础上，对ＡｕｔｏＣＡＤ软件进行二次开发，建立了符合船舶专业标准和规范的舱室布置要素图形数据库，并设计了多种优化交互功能和控制菜单。软件以人体工程基本原理和一般的舱室布置经验数据作为设计的边界约束条件，通过交互设计进一步体现设计者的美学知识、实践经验及特殊的要求，实现船舶舱室平面布置设计及图面生成。     

基于微机的集散控制系统组态软件的设计与研究

利用ＢＯＲＬＡＮＤ Ｃ＋＋语言支持的面向对象的程序设计方法ＯＯＰ在ＷＩＮＤＯＷＳ环境下对基于微机的集散控制系统ＭＴＤＣＳ的软件组态问题进行了研究，做了具体编程设计工作，实现了可用于ＭＩＤＣＳ的上位机组态软件。它可以编辑任意流程画面，并实现动态显示；还可以进行常规算法组合，生成的可执行件可以下装到ＭＴＤＣＳ控制站。该软件对于大滞后的过程控制系统是有效的。     

AutoCAD在有限元前处理中的应用

ＡｕｔｏＣＡＤ是一种通用的交互式图形软件。对ＡｕｔｏＣＡＤ进行二次开发,通过获取ＡｕｔｏＣＡＤ系统提供的用于图形信息交换的文件（文件扩展名为“．ｄｘｆ”）,并且编制相应的接口程序,可以方便地进行有限元分析的边界节点的设置,还可利用ＡｕｔｏＣＡＤ平台显示已生成的网格,这样大大减轻了有限元分析师的工作量,并能随时控制生成网格的品质。 一、边界节点的自动划分 １．节点的设置 利用ＡｕｔｏＣＡＤ为用户提供的“Ｐｏｉｎｔ Ｓｔｙｌｅ”菜单命令,设置节点的显示状态和尺寸大小,设置对话框如图１ 所示。执行键盘输入…     

SABRE—5000CAD／CAM软件在汽车覆盖件模具制造上的应用

本文介绍了ＳＡＢＲＥ—５０００ＣＡＤ／ＣＡＭ软件系统的总体结构，重点分析了汽车覆盖件模具典型曲面的特点，并在此基础上提出了这些曲面的造型方法；还对刀具运动轨迹的生成和编辑方法进行了讨论；最后介绍了采用ＳＡＢＲＥ－５０００软件进行中支柱零件的曲面造型及刀具运动轨迹生成的一个实例。     

SABRE—5000CAD／CAM软件在汽车覆盖件模具制造上的应用

本文介绍了ＳＡＢＲＥ－５０００ＣＡＤ／ＣＡＭ软件系统的总体结构，重点分析了汽车覆盖件模具典型曲面的特点，并在此基础上提出了这些曲面的造型方法；还对刀具运动轨迹的生成和编辑方法进行了讨论；最后介绍了采用ＳＡＢＲＥ－５０００软件进行中支柱零件的曲面造型及刀具运动力轨迹生成的一个实例。     

一汽液压设备叠加阀系统参数化设计VARY软件

本软件首次在国内液压系统ＣＡＤ上，采用ＡｕｔｏＣＡＤＲ１２．０最新添加的ＤＣＬ功能主中文环境，对叠加阀系统液压原理图进行了参数化设计，只要根据程序汉字操作提示输入液压设备的基本工艺参数和执行元件的动作循环要求，即可自动完成叠加阀系统液压原理图的设计，相应的集成装置装图与零件图均由软件控制自动生成。     

铝门窗设计,报价及下料系统

介绍一个计算机辅助铝门窗设计、工程报价及优化下料的ＣＡＤ软件。该系统在ＤＳＯ及ＡｕｔｏＬＩＳＰ语言，Ｔｕｂｏ ＰＡＳＣＡＬ语言的基础上，成功的对ＡｕｔｏＣＡＤ软件进行了二次开发。系统开发紧紧抓住铝门窗企业“设计－下料－生产”这条主线，实现了对铝门窗生产加工，备料，成本核算等基础信息的管理，构造出了上有待业特点的ＣＡＤ系统。     

一汽液压设备叠加阀系统参数化设计VARY软件

本软件首次在国内液压系统ＣＡＤ上，采用ＡｕｔｏＣＡＤＲ１２．０最新添加的ＤＣＬ功能及中文环境，对叠加阀系统液压原理图进行了参数化设计，只要根据程序汉字操作提示输入液压设备的基本工艺参数和执行元件的动作循环要求，即可自动完成叠加间系统液压原理图的设计，相应的集成装置装配图与零件图均由软件控制自动生成。     

起重机起升机构装配仿真的研究与实现

机械ＣＡＤ的一个重要内容是计算机仿真。本文总结了在起重机ＣＡＤ 系统中，利用微机上ＯｐｅｎＧＬ 图形库， 研制起重机起升机构仿真软件的理论和实现方法；着重讨论了三维图形在系统中的建立和运行过程。通过计算机仿真，使得ＣＡＤ 系统能够按照用户设计或分析的结果，真实地展示出起重机整机实时工作的情况，并根据其工作状态不断地调整设计方案。     

Automatic,parallel and fault tolerant mesh generation from CAD

HEXAR, a new software product developed at Cray Research, Inc., automatically generates good quality meshes directly from surface data produced by computeraided design (CAD) packages. The HEXAR automatic mesh generator is based on a proprietary and parallel algorithm that relies on pattern recognition, local mesh refinement and coarsening, and variational mesh smoothing techniques to create all-hexahedral volume meshes. HEXAR generates grids two to three orders of magnitude faster than current manual approaches. Although approximate by design, the resulting meshes have qualities acceptable by many commercial structural and CFD (computational fluid dynamics) software. HEXAR turns mesh generation into an automatic process for most commercial engineering applications.     

Meshing complexity: predicting meshing difficulty for single part CAD models

This paper proposes a method for predicting the complexity of meshing computer aided design (CAD) geometries with unstructured, hexahedral, finite elements. Meshing complexity refers to the relative level of effort required to generate a valid finite element mesh on a given CAD geometry. A function is proposed to approximate the meshing complexity for single part CAD models. The function is dependent on a user defined element size as well as on data extracted from the geometry and topology of the CAD part. Several geometry and topology measures are proposed, which both characterize the shape of the CAD part and detect configurations that complicate mesh generation. Based on a test suite of CAD models, the function is demonstrated to be accurate within a certain range of error. The solution proposed here is intended to provide managers and users of meshing software a method of predicting the difficulty in meshing a CAD model. This will enable them to make decisions about model simplification and analysis approaches prior to mesh generation.     

基于T-Spline的全自动几何拓扑修复方法

从高质量曲面网格生成的需求出发,提出了一种基于T-Spline的全自动几何拓扑修复方法.本文方法创新性主要可归纳为:1）对原有计算机辅助设计（Computer aided design,CAD）几何模型不进行任何修改保留其本真,自动识别CAD几何模型中常见不必要的几何特征,成功解决了CAD几何模型中存在的几何瑕疵,如短边、窄面、退化边、退化面、非连续光滑边界及尖锐特征等,利用新生成的"虚边"、"虚面"处理几何瑕疵,同时通过虚拓扑重构CAD几何模型的B-Rep;2）开发了一套CAD/CAE集成系统,统一了几何模型与计算分析模型,实现计算机辅助工程（Computer aided engineering,CAE）与CAD两者的无缝集成,所有拓扑修复操作及后续CAE分析计算均在同一环境下进行,避免了几何模型在CAE与CAD系统间进行转换时造成的数据丢失.该方法能够对复杂实体实现全自动几何拓扑修复及网格生成,实验表明,在保证不失真的前提下,修复后的几何模型能够生成质量良好的网格且能降低网格的生成规模,验证了本文方法的实用性和有效性,以满足工程实际分析的需要.     

基于ADAMS的装载机工作装置优化

装载机工作装置的优化是一个非常复杂的问题,在保证各性能指标的情况下,工作装置的自动放平性能成为优化设计的目标.基于机械系统动力学软件ADAMS环境,对装载机工作装置中各主要杆件进行参数化,创建了装载机工作装置的虚拟样机优化模型.采用目前最先进的OPTDES非线性二次规划计算方法,以装载机工作装置连杆机构的平移性和自动放平性能为目标进行了优化设计.提出的轮式装载机工作装置的连杆机构参数优化设计的新方案简单、直观且精度高.通过优化分析使铲斗的平移性得到了进一步的提高,自动放平性能得到了更加明显的改善.     

无线传感器网络软件动态加载技术研究

以Arena操作系统的设计技术为基础,构建了一个适合无线传感器网络软件动态加载的总体设计方案,详细给出了动态对象加载器的接口设计技术。该设计减小了系统运行时的内核镜像,实现了系统在运行状态下动态加载和卸载软件模块的功能,同时保证系统长时间可靠运转并具备高可配置能力,从而有利于系统软件的升级和后期维护。模块动态加载实验验证了该设计方案的可行性。     

Feature-based modeling for automatic mesh generation

Automatic meshing algorithms for finite element analysis are based on a computer understanding of the geometry of the part to be discretized. Current mesh generators understand the part as either a boundary representation, an octree, or a point set. A higher-level understanding of the part can be achieved by associating engineering significance and engineering data, such as loading and boundary conditions, with generic shapes in the part. This technique, called feature-based modeling, is a popular approach to integrating computer-aided design (CAD) and computer-aided manufacturing through the use of machinable shapes in the CAD model. It would seem that feature-based design also could aid in the finite element mesh generation process by making engineering information explicit in the model.This paper describes an approach to feature-based mesh generation. The feature representation of a fully functioning feature-based system that does automatic process planning and inspection was extended to include finite element mesh generation. This approach is based on a single feature representation that can be used for design, finite element analysis, process planning, and inspection of prismatic parts. The paper describes several advantages that features provide to the meshing process, such as improved point sets and a convenient method of simplifying the geometry of the model. Also discussed are possible extensions to features to enhance the finite element meshing process.     

A new approach to automatic and a priori mesh adaptation around circular holes for finite element analysis

Through our research on the integration of finite element analysis in the design and manufacturing process with CAD, we have proposed the concept of mesh pre-optimization. This concept consists in converting shape and analysis information in a size map (a mesh sizing function) with respect to various adaptation criteria (refining the mesh around geometric form features, minimizing the geometric discretization error, boundary conditions, etc.). This size map then represents a constraint that has to be respected by automatic mesh generation procedures. This paper introduces a new approach to automatic mesh adaptation around circular holes. This tool aims at optimizing, before any FEA, the mesh of a CAD model around circular holes. This approach, referred to as “a priori” mesh adaptation, should not be regarded as an alternative to adaptive a posteriori mesh refinement but as an efficient way to obtain reasonably accurate FEA results before a posteriori adaptation, which is particularly interesting when evaluating design scenarios. The approach is based on performing many offline FEA analyses on a reference case and deriving, from results and error distributions obtained, a relationship between mesh size and FEA error. This relationship can then be extended to target user specified FEA accuracy objectives in a priori mesh adaptation for any distribution of circular holes. The approach being purely heuristic, fulfilling FEA accuracy objectives, in all cases, cannot be theoretically guaranteed. However, results obtained using varying hole diameters and distributions in 2D show that this heuristic approach is reliable and useful. Preliminary results also show that extension of the method can be foreseen towards a priori mesh adaptation in 3D and mesh adaptation around other types of 2D features.     

Integration of CAD and boundary element analysis through subdivision methods

Subdivision methods have been mainly used in computer graphics. This paper extends their applications to mechanical design and boundary element analysis (BEA), and fulfills the seamless integration of CAD and BEA in the model and representation.Traditionally, geometric design and BEA are treated as separate modules requiring different representations and models, which include continuous parametric models and discrete models. Due to the incompatibility of the involved representations and models, the post-processing in geometric design or the pre-processing in BEA is essential. The transition from geometric design to BEA requires substantial effort and errors are inevitably introduced during the transition. In this paper, a framework of realizing the integration of CAD and BEA was first presented based on subdivision methods. A common model or a unified representation for geometric design and BEA was created with subdivision surfaces. For general 3D structures, automatic mesh generation for geometric design and BEA was fulfilled through subdivision methods. The seamless integration improves the accuracy of numerical analysis and shortens the cycle of geometric design and BEA.     

模块机器人及计算机辅助设计

本文利用新一代计算机辅助设计方法,开展模块机器 人的设计方法论和CAD系统的研究,旨在提出解决柔性加工系统的计算机辅助设计智能软件 的思路和框架．本文以模块机器人的设计为突破口,提出了以面向任务为特征、基于事例的 设计方法在机械概念化设计中的应用．论文中介绍了近年来发展迅速的模块机器人的标准模 块和基本拓扑关系,根据模块机器人概念化设计的特征,结合人工智能应用中基于事例的推 理机制,提出了面向任务和基于事例的计算机辅助设计方法和应用软件的框架,以及实现自 上而下的计算机推理的流程．文中还介绍了面向用户的机器人任务和工作环境的表示．     

粒子群算法用于装载机工作装置优化计算

装载机的工作装置是组成装载机的关键部件之一,其设计水平的高低直接影响工作装置性能的好坏,进而影响整机的工作效率与经济性指标。本文基于MTLAB,运用粒子群算法对ZL50装载机工作装置的连杆机构进行优化计算并对计算结果进行分析。