Effectiveness of Design Procedures in Counteracting Second Order Effects in Steel Moment Resisting Frames

The seismic response of structures is always influenced by second order (P–Δ) effects. importance these effects becomes significant when the structure experiences large plastic deformations. Seismic codes indicate that P–Δ may be counteracted means an increase lateral strength required a first analysis, but expressions Strength Amplification Factor (SAF) given in are often criticized researchers. This paper proposes and validates formulation SAF for Moment Resisting Frames (MRFs), which generalization derived past some authors based on SDOF systems. To this end, stage research set steel MRFs designed analyzed neglecting determined nonlinear static incremental dynamic analyses mean annual frequency exceedance Significant Damage (SD) Near Collapse (NC) limit states computed. In stage, each re-designed considering design according to provisions European, American Canadian or other formulations proposed literature, such as Bernal authors. accuracy accounting comparing stages.