Effects of Modeling Uncertainties on Fragility Curves of MRFs Considering Accumulation Damage

Incorporating structural modeling uncertainties along with record-to-record variability is of great importance in seismic performance evaluation of structures. It is important to consider these uncertainties in order to accurately estimate the seismic response of structures. On the other hand, structures may be excited by successive earthquakes which can cause accumulative damage in them. Therefore, taking into account the effects of repetitive earthquakes on seismic behavior of structures should be considered as a necessary topic since the seismic design of buildings in most parts of the world is based on the main characteristics of the mainshock. In this study, Latin hypercube sampling was employed to consider the effects of modeling uncertainties in a 4-story steel moment-resisting frame. In this paper, state-dependent fragility which provides a prediction of potential damages during successive earthquakes is plotted for the considered benchmark frame with probabilistic modeling parameters. Moreover, a sensitivity analysis was carried out for different structural modeling input parameters based on the Spearman rank-order correlation. Results showed that the damping ratio has the most impact on estimations.