Research And Development Of Computer-Aided Design System In Space Grid Structure

Space-grid structures are used in a lot of architecture for their abundant forms, good structural capability and better economy benefit. During the two decades, the space grid structure was becoming a very popular structure type. Now.the span of this kind of structure is becoming larger and the form is becoming more complicated increasingly.lt is very important to work out the CAD software that is used to design the space grid structure.On the basis of summarizing the similar software's strongpoint and shortcoming, the key techniques used to develop the computer-aided design system are studied especially in this thesis.In this thesis, a new input way of structure skentch was gained . Utilizing ActiveX Automation ,the system can manage AutoCAD to directiy create some entities such as lines and spheres that are used to figure the bars and nodes. At the same time,the information of bars and nodes can be generated automationlly through analyzing these entities' correlative data. While the application is running,the user can intercommunicate with the system and achieve the information of loads and boundary restraint. By this means,the applicable range of the pre-processing is extended.This thesis workout the program of analysing and desgining based on finite element method. Moreover, puts forward the issues in practice calculating throughresults that have been calculated. In light of object-oriented idea.this paper detailed studied how to deal with mixed-language programming in Windows environment with VB and Fortran. VB and Fortrant mixed-language programs are successfully implemented to improve the system's effect.This thesis also studied the design of line. Making use of ActiveX Automation , the intercommunicating connection between the application and Excel is established. Then it is very easy to deal with and design data.The system of this thesis consist of pre-processing module, structure anslysis module and post-processing module.The article introduced design of each module and design of data structure and data files. Finally, credibility of the system is verified by calculating examples.