This thesis presents the results of a study of several reanalysis procedures as applied to the fully stressed design of rigid-framed structures. The objective of the research project undertaken was to: (1) provide a literature review presenting state-of-the-art techniques used in reanalysis, (2) introduce two methods of reanalysis which are developed and used in this study, (3) conduct studies to evaluate the feasibility of each of these methods, and (4) present recommendations pertaining to the use of reanalysis methods. The two methods include an exact method (matrix displacement method) and an approximate method, labeled the modified stress method in this paper. The results of several example problems show that the approximate method produces accurate results while reducing the required computer solution time. Finally, a discussion of applications of reanalysis to other phases of structural analysis/design, particularly in the area of structural optimization, is presented in conclusion of this project. / M.S.

The accuracy and reliability of three structural analysis and design programs were evaluated. The three programs considered were MicasPlus, STAAD III, and GTSTRUDL. Nine different test cases of three basic steel space frames were analyzed and designed using the programs. The nine cases were formed by modifying different modeling, analysis, and design parameters. Comparison of results obtained from the programs for each case was presented. It was found that the percentage differences in the analysis results obtained from the programs were typically less than five percent. For steel design, both MicasPlus and GTSTRUDL gave member sizes that were very close. It was also found that changing modeling parameters can have a significant effect on analysis results. This confirms the importance of accurate structural modeling. The functionality and usability of the three programs were also evaluated. After an extensive study of MicasPlus a list of suggested modifications and additions to the program was presented. / Master of Science