DEVELOPMENT OF A SOFTWARE FOR THE ANALYSIS OF FRAMES, TRUSSES AND GRILLAGES USING VISUAL BASIC LANGUAGE INTEGRATED INTO AUTOCAD

Abstract

The engineering industry is rife with various software packages which come in various shades and dimensions. Many a times, these software packages for analysis of structural problems are developed abroad and are usually based on conditions that prevailed in that clime. Also, most of these software are very expensive and are rarely affordable to the average individual or company. The aim of this project is to develop a simple but highly efficient software to analyse frames, trusses, and grillages, and any other structure that can be modelled into a joint - member framework using the 12 x 12 stiffness matrix. The developed software is then linked to AutoCAD so as to complement it with a graphical enhancement for the purpose of visualization only. An algorithm is first developed for the solution of structural problems using the 12 x 12 stiffness matrix. The advantage of using the 12 x 12 stiffness matrix procedure is that it simplifies and generalizes the analytic procedures, and the same algorithm and programme structure is required to analyse all the category of structures that falls under the purview of this research. Using the developed software, a typical test case for the programme, a full pylon truss is analysed with the programme to determine the effectiveness and accuracy of the coding. The programme is run with the data provided in the spreadsheet. The typical pylon consist of 282 joints and 677 members. The truss loading case is purely hypothetical for the limited purpose of this work, however exact loading subroutines may be added if so desired. The loadings are applied at the joints in this case and the pylon is supported on four of its joints. One of the joint is pinned, while the remaining three are roller supports. The results generated by this software are checked for accuracy and compliance and these results are compared with that generated by some other structural analysis software. When the results obtained from this software were compared with prokon software, it was discovered that the results of analysis were typically the same. Hence, it was concluded that this software is a very useful alternative for the solutions of structural problems that fall within the purview of the thesis only.