Life-Cycle Cost Based Optimal Retrofitting of Structures by Fluid Dampers

Abstract

A simulation-based, probabilistic framework is discussed in this paper for design of viscous dampers based on life-cycle cost criteria. This framework allows for explicit consideration in the design process of all important nonlinearities for both the dampers and the structural behavior, as well as of all sources of uncertainty related to the seismic hazard. It is based on an assembly-based vulnerability approach for estimating earthquake losses, and on description of the earthquake hazard through stochastic ground motion models. In this setting, the life-cycle cost is quantified by its expected value over the space of the uncertain parameters for the structural and excitation models, and is estimated through stochastic simulation. For the design-optimization an algorithm appropriate for costly global optimization problems is adopted. An illustrative example is presented that considers the optimal life-cycle based design of fluid viscous dampers for retrofitting a three-story concrete structure.