https://www.journalisss.ir/ Journal of Steel & Structure en daily 1 Sat, 21 Mar 2026 00:00:00 +0330 Sat, 21 Mar 2026 00:00:00 +0330 https://www.journalisss.ir/article_243288.html This research evaluates the seismic performance of special moment-resisting steel frames (SMRSFs), both with and without viscous dampers, using nonlinear static (Pushover) analysis per Standard 2800 and Incremental Dynamic Analysis (IDA) as a benchmark for collapse assessment. The study examines 3D 12- and 16-story structures, with eight models each (four bare, four with dampers), designed for high seismicity and soil type III, using SAP2000-V19. Key findings indicate that changing columns from square to rectangular sections increases vulnerability and story drift ratios, while increasing the number and length of spans in the Y-direction reduces absolute lateral displacement. Results from both Pushover and IDA methods are consistent and confirm that viscous dampers significantly reduce the dispersion of IDA results, enhance energy dissipation, and decrease both absolute and relative displacements across all seismic intensities. Furthermore, the IDA clearly demonstrated that dampers increase the structure's maximum tolerable acceleration before reaching critical collapse thresholds, effectively shifting structural capacity curves to safer levels and confirming their effectiveness in improving seismic safety.