Elastic and Inelastic Input Energy Correlations: Effects of Damping, Pulse Type, and Significant Duration

In the seismic analysis and design of the structures, the energy-based approach has been considered a sought-after alternative to conventional design approaches in recent years. It accounts for the pulse type, frequency content, and duration-related cumulative damage potential of an earthquake. Precise computation of seismic input energy imparted into the structure during a seismic action is decisive in reaching a comprehensive energy-based seismic design method. Hence, based on the modal contributions, a methodology to determine the seismic input energy demands of multi-degree-of-freedom (MDOF) frames has been proposed. This paper evaluated the method through nonlinear response history analyses (NRHA) of four benchmark MDOF frames with three, six, nine, and twenty stories. The effects of the pulse type and significant duration of the ground motions, and the system’s damping characteristics on the elastic and inelastic input energy correlations were investigated. Whereas the correlation was not significantly affected by the significant duration of the earthquake record or the period of the structure, better correlations were detected for the structural systems with a 5% damping ratio under non-pulse-like ground motion records. The correlation between the elastic and inelastic seismic input energies was nearly 98%, with a maximum mean difference of 18.9% for the non-pulse-like ground motion records.