Seismic Fragility Assessment of RC Frame Equipped by Visco-Elastic Dampers Using NLTHA and FNA

In recent years, the issue of lower computational cost and analysis time has been the important factors for the structural analysts. In the meantime, after years of its introduction as an analysis having features of nonlinear analysis, the Fast Nonlinear Analysis (FNA) claims to have a higher performance speed than other nonlinear analyses, but has been less used by the researchers in this field. This research is conducted in order to improve the accuracy of the claim for a significant difference between the duration of structural analysis using the FNA method in comparison with the Nonlinear Time History Analysis (NLTHA) in  Sap2000 software. RC frame with two seismic resistant systems of Moment Resistant Frame (MRF) only and MRF equipped by visco-elastic dampers (MRF-VD) and efficiency of the FNA method has been investigated. The results indicated that in the analysis time, the structural analysis is decreased by 7-9 times, while the seismic fragility curves calculated for performance limit state of the frame does not provide an accurate estimate of the damage to the frame.