CAD System for Cylinder Head Used in High-Speed and Heavy-Power Diesel Engine

A CAD system for the cylinder head is developed. As an integrated system, it can be used in 3 D modeling, 2 D drawing and finite element structural analysis and optimization. The key problems in system designing are introduced. Design flow, system structure and how to solve the key problems are focused on. All of those would form the base for more research on how to use the modern CAD technology to design complex engine parts. And it is also a good example of using the modern CAD technology.

RESEARCH AND IMPLEMENTATION OF A WEB-BASED CAD SYSTEM

Computer aided design on the Internet/Intranet explores new frontiers in design environment. A new Web based CAD system is introduced. The users can install the CAD system on the server to build three dimensional models of products through a Web browser in any operation systems. No system installation and system maintenance are required. A new architecture and the database of system are discussed. The UML models of the system are presented. The proposed organization is implemented on the World Wide Web using Java and CORBA.

Research on CAD system of lever-hinge style welding fixture

A computer aided design system of welding fixture (called WFCAD system) is introduced in this paper. The microcomputer graphics software AutoCAD has been used as the supporting software of WFCAD system. By means of programming, 2-D and 3-D parameterized graphic libraries of components of welding fixture are established. With the aid of AutoCAD ' s advanced development system (ADS), menus and dialogs are constructed for convenient use of graphic library, and it also makes the system has a good man-machine interface.

DESIGN AND CAD SYSTEM OF THE TOOL FOR DRILL FLUTE

Based on the principles of differential geometry and kinematics, a mathematical model is developed to describe the grinding wheel axial cross-section with the radial cross-section of the flute in a given drill under the basic engagement condition between the generating flute and the generated grinding wheel （or disk milling tool）. The mathematical model is good for the flute in the radial cross-section consisting of three arcs. Furthermore, a CAD system is also developed to represent the axial cross-section of the grinding wheel （or disk milling tool）. With the system, the grinding wheel （or disk milling tool） axial cross-section that corresponds to the three-arc flute cross section can be conveniently simulated. Through the grinding experiment of drill flutes, the method and the CAD system are proved to be feasible and reasonable.

Intelligence in Clothing Pattern CAD System

It analyzes three recognition methods for five elements,i.e.dot,line,loop,clothing pattern as well as characters,and also applies intelligent points and tangential curve in the CAD system to solve the problem complained by CAD users.It indicates that recognition of five elements is a foundational technique of intelligence in clothing pattern CAD system.Common functions in operation state such as move,rotation,flip,measure,should precede ones in element state as dot,line,and pattern.Moreover,it is realized that the less skill the CAD user needs,the more the CAD software is high-tech.

Data Model Transformation in CAD System for Multi View Modeling

This paper describes multi view modeling and data model transformation for the modeling. We have proposed a reference model of CAD system generation, which can be applied to various domain specific languages. However, the current CAD system generation cannot integrate data of multiple domains. Generally each domain has its own view of products. For example, in the domain of architectural structure, designers extract the necessary data from the data in architecture design. Domain experts translate one view into another view beyond domains using their own brains.The multi view modeling is a way to integrate product data of multiple domains, and make it possible to translate views among various domains by computers.

Web-Based Interactive VR-CAD System for Conceptual Design and Analysis

To overcome the bottleneck of the one-way translation from VR （ virtual reality） to CAD in VR-based CAD system, this paper proposes a Web-based VR-CAD system WVCD （ Web-based virtual conceptual designer） to support both customers＇and design team members＇involvement in the conceptual design and analysis activity over the Internet. It provides users with both parametric and freehand methods to create and edit 3D conceptual models with different levels of complexity in a VR environment intuitively without the need of switching between the VR environment and CAD tools. As a simple and low-cost VR-CAD system, WVCD can help to popularize and improve the Web-based collaborative conceptual design.

Feasible Method to Assess the Performance of a Lung Cancer CT Screening CAD System in Clinical Practice: Dependence on Nodule Size and Density

Detection of small pulmonary nodules is the goal of lung cancer screening. Computer-aided detection (CAD) systems are recommended to use in lung cancer computed tomography (CT) screening to increase the accuracy of nodule detection. Size and density of lung nodules are primary factors in determining the risk of malignancy. Therefore, purpose of this study is to apply computer-simulated virtual nodules based on the point spread function (PSF) measured in same scanner (maintaining spatial resolution condition) to assess the CAD system performance dependence on nodule size and density. Virtual nodules with density differences between lung background and nodule density (ΔCT) values (200, 300 and 400 HU) and different sizes (4 to 8 mm) were generated and fused on clinical images. CAD detection was performed and free-response receiver operating characteristic (FROC) curves were obtained. Results show that both density and size of virtual nodules can affect detection efficiency. Detailed results are possible to use for quantitative analysis of a CAD system performance. This study suggests that PSF-based virtual nodules could be effectively used to assess the lung cancer CT screening CAD system performance dependence on nodule size and density.

CAD System Dedicated to the Design of Sport Bike Frame Structure

This article aims to discuss the design process of the CAD system dedicated for sport bike frame structure, introducing in detail its design concept and the scheme of implementation. Based on the different usages of sport bikes and the requirements on the system made out by Beijing Hanglun Sport Apparatus Company Limited. Structural analysis on two types of bikes frames is carried out. The system defines the basic design parameters and analyses the constraint conditions.Then calculating formulas with constraint conditions are derived. The system solves equations with Visual C++ program, realizes input of the original data and output of the results through interactive system. With AutoCAD14.0 as the platform, the system uses VC++ and ObjectARX to realize auto output of bike frame graphics. The system has been put into use. Practice has affirmed that the system抯 convenience, applicability and reliability all have reached the expected goal.

Research on Technology of Wooden Furniture CAD System

This paper introduces the current situation of domestic furniture production as well as world furniture CAD products, puts forward the necessity of developing a dedicated CADsystem——WFCAD and its main functions. It analyzes in detail the applied technology and keytechniques, including geometric modeling, assembly, joint design, database linking and management. The application of WFCAD in furniture manufacturing enterprises and its further improvement are outlined.

Development of 2D casting process CAD system based on PDF/image files

A casting process CAD is put forward to design and draw casting process. The 2D casting process CAD, most of the current systems are developed based on one certain version of the AutoCAD system. However the application of these 2D casting process CAD systems in foundry enterprises are restricted because they have several deficiencies, such as being overly dependent on the AutoCAD system, and some part files based on PDF format can not be opened directly. To overcome these deficiencies, for the first time an innovative 2D casting process CAD system based on PDF and image format file has been proposed, which breaks through the traditional research and application notion of the 2D casting process CAD system based on AutoCAD. Several key technologies of this system such as coordinate transformation, CAD interactive drawing, file storage, PDF and image format files display, and image recognition technologies were described in detail. A practical 2D CAD casting process system named HZCAD2D（PDF） was developed, which is capable of designing and drawing the casting process on the part drawing based on the PDF format directly, without spending time on drawing the part produced by AutoCAD system. Final y, taking two actual castings as examples, the casting processes were drawn using this system, demonstrating that this system can significantly shorten the cycle of casting process designing.

Concurrent Design Study of the Petroleum Equipment CAD System

Military petroleum equipment, as the special device a nd tool for petroleum storage, transportation, filling, chemical analysis, detec tion and maintenance for the army, is an important means and basis of petroleum indemnificatory. To adapt to modern war in high-tech conditions, the petroleum equipment have to develop towards higher reliability, adaptability, maneuverabil ity, standardization, container and cell type with versatile multi-functions. As a new design theory and design process, concurrent engineering may prod uce remarkable benefit when applying to product development. With the aid of the state-of-the-art modeling and simulation technology, it foresees the future or even the whole life cycle of the products designed. Based on wide statistics and survey, the product design period is reduced by 1/2～1/3 with concurrent des i gn process. The application of concurrent design process in new petroleum equi pment development shall greatly accelerate the petroleum equipment updating an d promote their indemnificatory.

基于直接CAD几何模型的辐射场生成技术研究及应用

介绍了基于直接CAD几何模型的3维辐射场生成技术及其应用情况。在大规模并行非结构网格蒙特卡罗粒子输运方法的基础上,结合在线地图、SolidWorks等直接CAD几何模型,提出了1种适用于电子元器件、复杂厂房几何和大区域城市环境的高效辐射场生成模拟计算方法。并基于该技术实现了安卓设备电路板辐射场、复杂放射源迷道辐射环境和核辐射在百米量级城市环境建筑物区域的数值模拟,获取了全空间的辐射场中子注量率和能量分布信息,验证了该项技术在电子元器件辐照效应、放射源屏蔽设计和核辐射瞬发效应仿真应用中的可行性。

椅旁IPS e.max CAD高嵌体修复后牙缺损的临床效果探析

目的为评价CEREC椅旁CAD/CAM系统制作的IPS e.max CAD玻璃陶瓷高嵌体应用于根管治疗后牙缺损病例的临床效果。方法选择42例根管治疗后牙,应用高嵌体的牙体预备方式,采用CEREC椅旁CAD/CAM修复系统和IPS e.max CAD玻璃陶瓷,即刻完成修复体并粘接;修复1年后复查,参照改良修正后的美国公众健康服务标准(US Public Health Service Criteria,USPHS),在修复体边缘染色、边缘继发龋、修复体边缘适合性、修复体崩瓷折裂或脱落、修复体颜色、牙龈健康状况、修复体邻接关系、患者满意度8个方面进行评价。结果修复体边缘染色C级病例1例,成功率97.6%;边缘继发龋C级病例1例,成功率97.6%;修复体邻接关系欠佳C级病例1例,成功率97.6%;在边缘适合性、修复体崩瓷折裂或脱落、修复体颜色、牙龈健康状况、患者满意方面表现优秀,成功率均为100%。结论椅旁CAD/CAM系统制作的IPS e.maxCAD高嵌体修复体在短期内可取得良好的修复效果。

创新创业驱动的车身CAD教学模式探索

在创新创业国家战略背景下,以创新创业思维模式和能力培养为导向,对“车身CAD技术”实践课程内容进行综合改革,基于OBE理念进一步夯实与提升教学实效。以学生团队为中心设计教学过程和实验内容,围绕学生综合能力的培养制定多元化考核方式。综合使用数字化设计工具及先进仪器设备,实施“理论—实践—管理—创新—创业”的螺旋阶梯式五位一体教学。教学实践表明该模式显著的锻炼和提升了学生的创新创业能力。

高职CAD软件综合应用线上线下混合教学研究

针对CAD软件综合应用课程涉及看图识图、空间想象和计算机操作能力等特点,结合前期实际教学中出现的各种问题,提出“以学生为中心”线上线下混合式教学新策略解决现有问题。本文重点以“拉伸特征”的课内实验改革实践为例,教学改革后培养了学生自主学习能力和创新意识,提高了课程教学质量,优化了学生学习效果。

基于工程实践的工程制图与CAD课程题库建设与实践

为改善中医药院校学生工程实践机会不足、解决实际问题能力弱的现状,文章梳理了课程内容的知识点,并深入企业调研,收集工程实践案例,挖掘其与课程知识点的结合点。依托真实工程案例,精心设计工程案例题目,旨在通过习题与测试,引导学生将所学知识应用于工程实践中。这一系列基于工程实践的工程制图与CAD课程题库建设举措,不仅明确了学生的学习目标,激发了学生的学习兴趣,还有效提升了学生的学习效率,增强了教学效果,为其他工程类课程题库的建设提供了借鉴。

数字化技术在《电气CAD制图》课程建设中的应用研究

教育信息化背景下推进课程信息化建设,满足教育改革需求,促进教学理念转变,提高课堂教学质量。有鉴于此,本文中探究《电气CAD制图》课程建设中应用数字化技术的措施。通过分析《电气CAD制图》课程建设中数字化技术应用的作用,深入探讨数字化技术的具体应用,充分发挥数字化技术的优势,改善传统教学方式的不足,创新课堂教学理念,进一步提高课程建设质量,促进电气人才培养质量的提升。希望通过文中论述,能为课程建设提供借鉴与参考。

课程案例—任务驱动教学模式探索——以“采矿CAD”课程为例

基于工程教育专业认证标准和矿业类教学质量国家标准,融合OBE教育理念,结合专业特色和毕业要求,设置课程目标,重构知识体系。构建了“案例教学、任务驱动、考核反馈”三个教学模块,针对不同模块探索“理论学习、实践操作、综合训练”多层次教学形式,以实现“学生知识积累、专业技能、表达能力提升”的一体化目标,形成了基于OBE理念的高校CAD课程案例—任务驱动教学模式。新模式实践效果显著,对高校CAD课程教学具有借鉴价值。