correlations between earthquake parameters and variation of fundamental period in rc frames

in recent decades many researchers have studied on the damage assessment of structures after a seismic event. to assess the damage of structures after an earthquake, it is so important to study the correlations between earthquake parameters and damages of the structures. variation of fundamental period is one of the methods to identify the damage of the structures. in this paper correlation between earthquake parameters and variation of fundamental period is studied.to characterize a seismic event, a lot of parameters have been defined. in this paper several earthquake parameters are chosen to study. two rc frames are analyzed under far-fault earthquake records by nonlinear dynamic analyses. the correlations between earthquake parameters and variation of fundamental periods are calculated. the results show that some of the earthquake parameters have high correlations with variation of fundamental period. the most correlations are for those earthquake parameters which some researchers have shown high correlations between damage indexes of structures and them. so some earthquake parameters which have high correlations with variation of fundamental period can be proper indices to estimate the damage potential of an earthquake.