Spectral-To-Structural Filtering of Acceleration-Defined Exceedance into Realized Input Energy in Regular and Torsionally Irregular RC Frames

Acceleration-defined spectral exceedance bands – the period intervals in which a recorded acceleration response spectrum exceeds the code-based design spectrum – are commonly read as direct indicators of structural severity. Using records of the 2023 Elbistan earthquake applied at multiple orientations to regular and torsionally irregular reinforced-concrete frames, this study shows that such exceedance is a conditional indicator: structural significance requires joint period alignment and input-energy spectral relevance. Realized input energy is consistent with an effective modal mass baseline (median normalized efficiencies of 0.89–1.02), correlates strongly with peak roof displacement, and varies with the adopted structural configuration and loading direction.