An adapted weakening and high damping approach for seismic protection of structures

Seismic isolation is widely used in the structures to dissipate the destructive energy of an earthquake by decoupling the superstructure from the ground. High-damping rubber (HDR) devices, as a type of energy dissipating device, used in structural systems to control the structural response under energetic excitations such as earthquakes. This paper uses the Weakening and Damping (WeD) scheme to realize a modified approach in reducing all of the structural responses simultaneously. By this modification, Negative Stiffness Devices (NSDs) are used for the weakening phase to lessen lateral strength. The HDR device is used as a part of NSDs components. HDR generates a high damping force to establish a modified "Weakening and High Damping" (WeHD) concept and gain optimal performance in the overall structural responses. Use of the HDR in seismic base isolation not only prevents permanent deformation under strong motions but also works as an energy dissipating device even during the small ambient vibrations. Since the structure could be unstable by using NSDs, MR dampers are added to preserve stability. An inverse model is employed to command MR dampers by adjusting the voltage and generating the desired control forces. To further verify the proposed WeHD device, a smart base-isolated benchmark building framework is used. Based on the results, the proposed Weakening and High Damping (WeHD) approach not only reduces base displacements, accelerations, and shear but also leads to a reduction in the accelerations and inter-story drifts of the superstructure.