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

Ground motion intensity measures (IMs) play a significant role in earthquake engineering, especially during ground motion selection for nonlinear response history analyses, dynamic shake table tests, and 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 made for conventional IMs to relate them to the structural response. An empirical correlation study between energy-based and conventional IMs is required to benefit from these efforts. 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, considering different constant ductility levels, predictive models between energy parameters and spectral acceleration were suggested. Hence, ground motion characteristics reflected by the input and hysteretic energy can be explicitly considered in performance-based earthquake engineering applications.