In this paper, the plastic design with mechanism control (PDMC) for steel moment resisting frames (MRFs) is presented. The PDMC method in rigid plastic analysis, by considering the second-order effects, is guaranteed the achievement of global mechanism and prevented undesired mechanisms such as the soft story, which leads to decrease the ductility and energy dissipation capacity of the structures. The concept of PDMC is based on the plastic rotation of columns in developing a mechanism in which for a specified target displacement, the global mechanism has a minimum plastic rotation among all other undesired collapse mechanisms. In the presentedmethod, the design conditions for storymechanisms are derived by using an energy equilibriumequation. For demonstrating the accuracy of the proposed design procedures, both pushover and nonlinear incremental dynamic analyses (IDAs) are applied to evaluate the structural performance. The results show that the designed structures comprise high seismic performance and the design objective thatwas to obtain a globalmechanismis achieved.
