Development Of CAD System For Single Section Continuous Beam Of Middle-Small Span

CAD and CAM - Computer-Aided Design and Computer-Aided Manufacture, are new applied technologies developed along with the computer technology. CAD and CAM have had a rapid development from 1950's. Some special systems for structure design had been developed, as well as some software libraries and blocks for bridge structure design based on AutoCAD.The present study is for the key point of development of the Single Section Continuous Beam of Middle-Small Span CAD System (SSCBMS), which is based on database management. This study has developed a system of CAD technology in bridge design, mainly including the function of SSCBMS, structure of the system, interface design of the system, the development condition of the system, with the emphasis on the design and organization and plan of the system database, the integration technology of the system and the realization of the system joints.This work is a part of a general system, which mainly resolved some key problems such as general layout of the system, the building of database, the integration technology of the system, and the menu of the system .In addition, the block diagram of the system and three dimensional model have also been established.Advanced technology must be used in developing the system, but the utilization of software early developed is also necessary. In the development of this system some beneficial work has been done, such as smooth transition from text data to database, which mixes the software early developed together with the system based on database. This can significantly decrease cost and time of the development of the system.Visual utilization of powerful figure function of modern computer, which transits digital information to visual figures, and interfering and conducting calculation make users know well about the calculating process. Three dimensional browse function of the system has just used visual technology to show whether the box beam is correctly designed.The present work has succeeded in resolving joint between SSCBMS and AutoCAD, this makes the possibility of the three dimensional browse function of the system and engineering drawings by the system. ActiveX Automation technology is the most advanced technology in the second development of AutoCAD, and the succeeded development of this system provide a new technique solution for the development of CAD in this field.