The performance-based seismic design has two primary concerns: (a) appropriate quantification of the uncertainties associated with the performance evaluation process, and (b) satisfactory characterization of the associated structural damage for direct incorporation into the design or performance evaluation methodology. This study deals with seismic damage assessment of moment resisting frames. Some damage indicators are introduced by using the nonlinear responses obtained at the output of

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... ear static procedures. Among these, some are possible extensions of previously defined static indicators and some are newly defined ones. The damage variables used in formulation are inelastic displacement, spectral displacement, spectral acceleration, and base shear. The introduced damage indicators address the plastic ductility, loss of strength, stiffness degradation, and dissipated energy of a structure. The variations in damage values for various drift criteria were used to associate with different performance levels.