Selected topics in development of a CAD application for sizing light gauge cold rolled steel roof trusses

Scope and Method of Study. The goal of the current project is to develop an application which will let users easily define building and truss geometries. Then, optimum truss member sizes will be calculated based on load inputs. The application will be user friendly with required features and is expected to facilitate a wide range of users. The purpose of this document's to discuss the selected topics involved in the development of this CAD application. The selected topics cover the use of an optimization technique to generate the desired roof slopes, the procedure to size the trusses, the data structure required for the computer program, the fonts to display text in 3D, the method to associate constraints on the geometry and the implementation of Undo/Redo functionality in the application.;Findings and Conclusions. The computer program lets user to generate a building in a 3D application. Snapping functionality and constraint feature is working correctly in the program. Once the user has defined the building geometry, the application will allow the user to define the location of trusses in the plan view. The user can also define group of trusses by defining a region and spacing between those trusses. Application will calculate the truss envelope based on the roof profile defined. User can define a custom truss or a pre-defined truss can be added from the available library. The results generated by the program are validated and a good match is found in the results. The application can also determine the optimum number of panels in any truss added from the library.