【作者】 王朝阳；

【导师】 段国林；

【作者基本信息】 河北工业大学 ， 机械设计及理论， 2007， 硕士

【摘要】 CAD技术是制造业的核心技术,大力发展自主CAD系统是我国制造业信息化发展道路中的重中之重。伴随着计算机软硬件技术的高速发展,CAD系统的开发向着更高、更深层次方向发展。基于CAD几何造型引擎进行的CAD系统开发与基于某个通用CAD系统的二次开发和完全从底层做起的开发方式相比,具有开发周期短、见效快、系统稳定性好、功能强的特点,是符合市场经济机制和合理分工原则,迅速提高国内CAD系统技术水平和市场占有率的有效方式。本文对当今国际上成功的三维几何造型引擎ACIS进行详细讨论和分析的基础上,基于面向对象技术和组件技术的思想,针对开发基于ACIS的自主三维CAD系统的需求,对ACIS的实体造型技术和组合夹具CAD系统的实现进行了研究,本文的研究工作主要包括:1、详细介绍了ACIS、HOOPS的基本内容,包括开发特点,数据结构以及ACIS类的层次定义和ACIS与HOOPS的关联方法;2、对比分析了国内外组合夹具CAD系统的研究现状,实现了组合夹具CAD系统的总体结构设计,遵循“软件工程”的思想,对系统进行了统一的规划,把庞大的系统设计分成若干子类,独立开发,缩短了系统的开发周期,提高了系统的兼容性和稳定性;3、采用基于窗口和面向对象的设计方法设计了良好的用户界面,使人机对话变得更加直观,操作更加简捷;4、利用ACIS提供的丰富完备的类库和函数库,实现了线框模型、曲面模型、实体模型的构造和操作;5、作为组合夹具CAD系统的进一步应用,在对国内外组合夹具CAD技术的研究现状进行分析的基础上,针对槽系组合夹具的设计特点,实现了组合夹具元件的参数化设计;6、综合考虑工程人员思维习惯及装配模型细节构建的设计过程,系统中实现了四种基本的装配约束方式:面对齐、轴重合、旋转、移动。更多还原

【Abstract】 CAD is one of the key technologies of manufacturing industry, it is important to promote the development of CAD systems in order to accelerate the information of domestic manufacturing industry. The development of CAD systems follows the high-speed development of technology of the software and hardware. Compared with developing a CAD system based on another CAD system or based on the way that totally starts from the ground floor, it is fast, effective, with good systematic stability and strong function that developing a CAD system based on a 3D solid modeling engine. It is according with the market economy mechanism and rational division of work principle, improving domestic CAD systematic engineering level and the effective way of the occupation rate of market rapidly.Based on the analyzing and discussing of the successful 3D geometry modeling engine ACIS, this paper goes on in detail with the method of object-oriented technology and component technology. In order to the aim of developing an independent 3D CAD system based on ACIS, this paper studies about entity modeling technology and implementation method of modular fixture CAD system based on ACIS. The main work can be summarized as follows:1. The contents of ACIS and HOOPS including ACIS developing characteristics, data structures, and hierarchy definitions of ACIS classes as well as methods to connect ACIS and HOOPS are deeply described in the paper;2. The current states of the world about CAD technologies’application on modular fixture systems are analyzed and compared with each other. The whole structure is designed following the thought of“Software Engineering”. The systems are classified into many sub-classes which then can be developed separately. By the above methods, the cycle of development is shortened and the compatibility and stability can be improved;3. Window-based and object-oriented methods are adopted and a good interface is designed which make connection and operation between human and computer more direct and simple;4. The class and function libraries provided by ACIS are so complete that wireframe model, curved surface model as well as solid model can all be constructed and operated;5. Based on the current state of CAD technology application on modular fixture in the world, the parameterized design of modular fixture is realized according to the design characteristics of T-slot-based modular fixture;6. The fundamental styles of assembling rules including“FaceAlign”,“CoAxis,”“Rotate”and“Move”are realized in terms of engineers’thought habit and model details to be assembled.更多还原