Vertical Isolation of 1-Story Structures with the Nonlinear Viscous Dampers for Seismic Response Reduction

The viscous dampers have been considered as preferred supplementary energy dissipating devices for structural vibration control, especially in innovative lateral displacement control strategies. The interactional effects of connected structures were first discussed as a seismic response reduction approach for building systems by Klein et al. (1972). In the vertically isolated structures (VIS), vertical isolation layers are applied in a way to partition the structure into two interactional inner and outer substructures (Ziyaeifar et al. 2012.) A comprehensive investigation was performed on displacement control features of the vertically isolated structures interconnected by viscous and viscoelastic links (Milanchian et al. 2017). In the present study, the effects of nonlinear behavior of viscous dampers in the efficiency of the VIS are taken into consideration. By using a set of earthquakes with a wide range of dominant periods, and conducting a series of nonlinear time history analyses, the application of nonlinear viscous dampers (NVDs) in the VIS has been thoroughly studied. In these analyses, the interaction effect of isolation ratios and link parameters on response control of the VIS was explored. Also, color contour graphs were defined for presentation and investigation of large amounts of output results, in which three states of Mass Isolation, Interactional State, and Control Mass have been differentiated.