Reliability-based design of fluid viscous damper for seismic protection of building frames

Viscous dampers are energy dissipation devices widely employed to control the structural response of mechanical and civil systems subjected to dynamic loadings. In particular, such dampers have been extensively applied in earthquake engineering to enhance the seismic performance of new and existing building frames. Although simplified methodologies for the preliminary design of the optimal damper properties are well established, they are often based on deterministic or semiprobabilistic approaches neglecting the response dispersion due to the uncertainties inherent to the seismic input and the system model. This paper proposes a reliability-based methodology for the optimal design of viscous dampers in structural systems subjected to the uncertain seismic input. The methodology is capable of controlling the probability of exceeding limit states related to the structural failure, while limiting the damper forces. Thus, it provides a useful means to identify the optimal damper properties based on performance-based criteria.