Empirical correlations of constant ductility seismic input and hysteretic energies with conventional intensity measures

Ground motion intensity measures (IMs) possess a significant role in earthquake engineering, especially during ground motion selection for nonlinear response history analyses and dynamic shake table tests as well as for probabilistic seismic engineering. Conventional IMs are not capable of accounting for the duration-related cumulative plastic damage, the frequency content of the ground motions, and the hysteretic behavior of the structural members which can be considered inherently by seismic energy-based IMs. However, many efforts have been paid for conventional IMs to relate them to the structural response. To benefit from these efforts, an empirical correlation study between energy-based and conventional IMs is required. To this end, constant ductility seismic input energy and hysteretic energy imparted to diverse single-degree-of-freedom (SDoF) systems were calculated for near-field earthquake records. The empirical correlations of the energy-based IMs with conventional spectrum-based, peak amplitude-based and cumulative-based IMs have been investigated based on the response history analyses. Further, predictive models between energy parameters and spectral acceleration were suggested considering different constant ductility levels. Hence, ground motion characteristics reflected by the input and hysteretic energy can be explicitly considered in performance-based earthquake engineering applications.