Research On Training System Of Parts Representation Based On AutoCAD

"Mechanical drawing" is an important compulsory course for engineering undergraduates; it is well known that one of the most important tasks is to develop students' capability of imagination and ideation, as well as the ability of representing a part with 2D drawing based on orthographic projection method, so 2D representation is a fundamental part of the course, and it is also a difficult knowledge point for students because of the traditional teaching procedure and practicing style.The training system of parts representation was based on AutoCAD, adopting VBA, and SQL server techniques to realize a series of specific functions. It supplied students with an open and highly-targeted learning environment, which can effectively improve their ability of representing a part. The major research work includes the following:1) Designed and created a fundamental part database, Studied data storage technology and data access technology.2) Made 2D views as blocks, During the designing process of 2D views, much attention has been paid to the diversity of parts representation scheme, and drawing conventions have been strictly followed. Some tips on how to work out the commonly-encountered problems while transferring 3D model to 2D views have been concluded.3) Realized interactive function for 3D model with Cult3D technique. Student can zoom or move the part by mouse operation, and also can rotate the part to observe it freely.4) Analyzed the selection principle and components of parts representation scheme, put forward an automatic check strategy and applied it to the training system, successfully realized automatic check function.5) According to students' and teachers' requirements, designed and realized a series of function module such as identity verification module, parts selection module, 2D views selection module, files management module, output module and add new parts or new representation scheme module etc.The training system included some typical 3D models, and Cult3D interactive technique has been successfully applied to the system, which supplied students with vivid 3D models, and greatly stimulate their interests. After choosing a part to practice, students also can observe the part's structure freely; select some 2D views in the drawing area of AutoCAD to form a certain representation scheme, and then submit it, the system would perform automatic check function, and put forward a judgment to the scheme. At the same time the preferred representation scheme would be available to students. In this way, the system would greatly improve students' learning efficiency, and also be helpful to broaden students' thinking way.