Experimental study on a novel replaceable yielding-based energy dissipater for rocking and seesaw buildings

Abstract

The use of energy dissipaters for creation of earthquake-resilient buildings has been paid more and more attention in recent years, and some newly developed structural fuses or dampers have been proposed to be employed in rocking and seesaw buildings. In this study, a new type of yielding-based dampers, called curved-yielding-plates energy dissipater (CYPED), is introduced. CYPEDs are installed at the bottom of rocking or seesaw building's circumferential columns at the lowest story and have hysteretic behavior in their deformation occurring in vertical direction. The initial curvature of the yielding plates prevents them from buckling and gives the device a smooth force-deformation behavior. First, by performing a set of cyclic tests on three specimens of CYPED, their hysteretic force-displacement behavior was investigated. Then, to show the efficiency of this energy dissipating device in reducing the seismic response of buildings, they were employed numerically as multilinear plastic springs in the computer models of a sample seesaw steel building, and a series of nonlinear time history analysis (NLTHA) were performed on both seesaw building and its conventional counterpart. Results of NLTHA show that the proposed seesaw structural system equipped with appropriate CYPEDs not only gives the building a longer natural period, leading to lower seismic demand, but also leads to remarkable energy dissipation capacity in the building structure at base level and, therefore, keeping the seismic drifts in elastic range in all stories of the building. In this way, the building structure does not need any major repair work, even after a large earthquake, while the conventional building suffers from heavy damage and is not usable after the earthquake.