CAD Ststem Of Modular Fixture Based On ACIS

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.