Seismic performance of isolated buildings with friction spring damper

The main objective of this paper is to introduce a new combination of passive seismic response control devices containing Friction Spring Damper (FSD) and Pot Bearing (PB) for buildings and compare this system with conventional seismic isolators such as Lead Rubber Bearing (LRB) and Friction Pendulum System (FPS). For this purpose, two benchmark buildings with different structural systems have been considered for implementing the devices. To capture the flag-shaped and self-centered behavior of FSD, new uniaxial material has been developed for OpenSees, and numerical verification of the material has been done based on a past experimental study. Nonlinear dynamic time-history analyses have been used to extract the seismic responses of models, including fixed-base structures, and isolated structures by FSD along with PB, LRB, and FPS. The results show that not only the proposed isolation system has the capability of reducing base shear and inter-story drift as well as both conventional seismic isolation systems compared to fixed-base structures, but also the system has even better performance than the isolated structures with LRB. Moreover, due to the self-centered behavior of FSD, the residual displacement of the proposed system is much lower than conventional isolation systems, which can lead to lower maintenance costs of isolators.