Cyclic behavior of an energy dissipation system with steel dual-ring dampers (SDRDs)

Abstract

In this paper, the energy absorption system of a steel dual-ring damper (SDRD) is presented and its cyclic behavior is studied analytically and numerically. The energy dissipation mechanism of the SDRD occurs through the formation of moment plastic hinges in steel rings. The purpose of this study is to provide an analytical relationship for estimating the yield strength, yield displacement, and elastic stiffness of the proposed SDRDs. An analytical relationship is presented for calculating the elastic stiffness of SDRDs using the structural analysis method. Also, using plastic analysis and considering the mechanism of plastic hinge formation, a relation has been obtained for estimating the yield strength and yield displacement of SDRDs. Extensive parametric studies have been carried out using a nonlinear finite element method to examine the accuracy of the obtained analytical relationships. The parametric studies include investigating the influence of thickness parameters as well as the inner and outer ring diameters of SDRDs. Nonlinear static analysis is employed to analyze finite element (FE) models under cyclic loading. Also, validation of the results of the finite element models is performed with experimental specimens. There is a good agreement between the results of yielding capacity, yielding displacement, and elastic stiffness of the analytical relationship and FE models parametric studies. The results of the parametric models and the proposed relationship reveal that with elevation of the steel ring diameter, the energy dissipation has increased. Also, as the diameter to thickness (D/t) ratio increases, ductility and equivalent viscous damping ratio are reduced.