The Effect of Record Selection Technique on Dissipated Hysteresis Energy and Park Ang Damage Index in Moment Resisting RC Frames

The main sources of the uncertainty in estimation of structural seismic responses is the uncertainty of the earthquake records as the input excitations. In recent years, along with the development of performance-based seismic design approaches, importance of the record selection strategies in nonlinear response history analysis of structures has been highlighted and has attracted the attention of many researchers. Record selection in performance-based seismic design approaches is often done based on the intensity measure of the records. The spectral shape has been introduced as a powerful intensity measure in record selection techniques for estimation of some structural responses such as the maximum inter-story drift ratio. In the present study, the sufficiency of the spectral shape in assessment of hysteresis energy of the structure and the maximum Park Ang damage index in plastic hinges has been investigated in special moment-resisting RC frames. In this way, four 2D structural models of special moment-resisting RC frames with inelastic characteristics have been analyzed under a set of strong ground motion records selected based on the spectral shape by the conditional spectrum method. After determination of numerical values of hysteresis energy of the structure and maximum Park-Ang damage index in the plastic hinges, the correlation of such responses have been investigated with the various secondary intensity measure. These intensity measures are selected such that they cover various properties of strong ground motion records such as frequency content and duration. The results indicate that spectral shape is not sufficient for prediction of hysteresis energy and Park-Ang damage index of special moment-resisting RC frames. To obtain an unbiased and reliable estimate of such responses, more studies on record selection strategies is needed. Among the secondary intensity measure, those associated with the energy content and duration of the records are more correlated with the aforementioned structural responses.