Research And Development Of Space Grid Structure System Based On ObjectARX

Space grid structure is a sort of preferable roof type for long span buildings. As a popular form of steel structures, it is widely used in various buildings. At present, the computation and design of space grid structure are completed by Computer Aided Design (CAD) software on the whole. The CAD technique skillfully combines high-speed operation, data processing and drawing of the computer with human creativity and reasoning ability ideally. So CAD has become an essential technical tool in the field of engineering design.Currently, Object-Oriented Programming (OOP) is taking the place of the traditional structural methods to become the mainstream of software-development. ObjectARX is a brand-new tool for AutoCAD secondary development based on object-oriented method. It makes secondary development of AutoCAD convenient and powerful by means of Visual C++. With the powerful tool, the object-oriented programming is introduced to secondary development of structural CAD, and it is possible to develop a CAD software, which is applied to data processing and structural analysis based on graph operation system.The space gird structure CAD system (TRUSSCAD system) in this thesis is developed based on the object-oriented programming method, which uses the VC++ programming technique, AutoCAD developing tool-ObjectARX and other techniques under the Windows operating system. The TRUSSCAD system has three modules, which are pre-process module, computing module and post-process module respectively. The pre-process module mainly performs these tasks, such as quick modeling, defining section and constraint, applying load, collecting data by dialog boxes. Moreover, the informations of the nodes, the member bars and the loads are obtained automatically. The computing module deals with structural computation and section checking, and gets node displacement and internal force, etc. The post-process module is in charge of drawing in the AutoCAD environment, exporting material list, displaying deformation map, etc. Therefore, the TRUSSCAD system not only continues to use powerful graphical function and better user interface of AutoCAD, but also keeps easy oprating to make users master operating method without training. In addition, the system has relatively better stability and efficiency, and it is comparatively in close touch with engineering design.