| The objective of this study is to develop a computer procedure for the optimum performance-based design of semi-rigid connected steel frames at different performance levels. The conventional elastic and geometric stiffness matrices of frame elements are systematically modified to reflect the progressive degradation of structure stiffness due to both plastic behavior and connection rigidity influences under incrementally increasing loads. This study also includes a finite element model for some types of semi-rigid connections in order to investigate the behavior of the connection under loading.; An optimization process is introduced using a genetic algorithm with a detailed pushover procedure. Inter-story and roof drift, and strength and the rigidity factor constraints corresponding to the various performance levels are all accounted for by the optimization model. Different damage contributions and different connection cost contributions to the objective function are presented. Finally, a comparison between the results of optimization of the advanced and the modified analysis method is presented. |
