Minimum failure cost-based energy dissipation system designs for buildings in three seismic regions – Part II: Application to viscous dampers

• Minimum failure cost-based framework to obtain optimal viscous damping systems.
• Optimal design focuses on reducing the failure costs for more frequent seismic events.
• Response spectrum method is quite accurate for minimum failure-cost damper designs.
• Optimal design achieves reduced fragility for all expected seismic motions.

A methodology for calculating the life-cycle cost of building structures under seismic loading was presented in the companion appear Shin and Singh, 2014. In this paper, this methodology is applied to obtain the minimum failure cost-based optimal designs of fluid viscous dampers for model structures in three different seismic regions in the USA. Genetic algorithm is utilized to obtain the optimal number and location of dampers to be installed on the buildings. The failure costs are optimally reduced at all seismic intensities that are expected to occur on the site to achieve the minimum life-cycle and object costs. The numerical results show the impact of optimal designs on structural performance in terms of reduced fragilities covering different performance objectives over the spectrum of expected seismic intensities. The results also demonstrate that although the structural system may go in inelastic range at the higher intensities of motion, the response spectrum method can still be effectively used for the failure cost-based optimal design of linear damper.