Energy-based design method for seismic retrofitting with passive energy dissipation systems

In this paper a stepwise multi-mode energy-based design method for seismic retrofitting with passive energy dissipation systems is proposed as an alternative to strength and displacement-based methods. The method utilizes modal pushover analysis to determine modal yield force and ductility factor of an equivalent single-degree-of-freedom system. Two modes with the highest participation factors are accounted for. The energy contribution of each mode is determined using energy spectra and the required amount of energy dissipation is estimated and used to retrofit the original structure with appropriate energy dissipation system. The effectiveness of the proposed method is verified using nonlinear time-history analysis. It is concluded that the proposed method is easy to implement and yields an effective retrofitting design in which damage is confined within the dissipative system.