Estimation of Cyclic Demand in Metallic Yielding Dampers Installed on Frame Structures

Abstract

The efficacy of hysteretic dampers can be formulated as the number or equivalent inelastic cycles, or the ratio of normalised dissipated energy to displacement ductility. This parameter is used in the design of framed structures with supplemental dampers and it is strongly influenced by the impulsive effects of earthquakes and other structural parameters. This paper presents an estimate of the cyclic demand of dampers installed in reinforced concrete frames, based on nonlinear time history analyses. Statistical analyses of the results are used to highlight relevant parameters and calibrate a predictive formula and upper-bound design values. The collapse pattern of the frames seems to have no effect on the efficacy of the dampers; thus, the seismological parameters that describe impulsivity should drive the design of hysteric dampers.