Pushover Response and Plastic Hinge Evolution of Steel SMRF with Panel Zone Representation

This study investigates the pushover response and plastic hinge evolution of a six-story steel Special Moment-Resisting Frame (SMRF) incorporating panel zone representation. Nonlinear static pushover analyses were conducted in the X and Y directions using ETABS under displacement control, considering P–Delta effects. The structural response was evaluated through capacity curves, plastic hinge status and distribution, and interstory displacement. The maximum base shear reached 20,830.91 kN in the X direction at a roof displacement of 0.326 m, compared with 6,748.74 kN in the Y direction at 0.323 m. At the final reported analysis steps, 102 hinge records classified as Immediate Occupancy–Life Safety (IO–LS) were distributed across Stories 2–4 in the X direction, whereas 54 records were concentrated on Story 2 in the Y direction. The maximum recorded interstory displacements were 0.021915 m at Story 3 in the X direction and 0.040266 m at Story 2 in the Y direction. These findings demonstrate directional differences in lateral capacity, hinge-status distribution, and deformation response. Further assessment requires drift-ratio verification and comparison at equivalent roof displacements