Seismic retrofit of structures using rotational friction dampers with restoring force

Abstract

In this study, the seismic performance of a rotational friction damper with restoring force is presented. The torsional spring friction damper consists of rotational friction pads with the heavy duty torsional springs attached on both sides of the friction damper. An analytical model and a design procedure for the damper are developed using capacity spectrum method. A parametric study is carried out to investigate the influence of the torsional spring in the response of the structure when subjected to ground motions. The seismic performances of steel structures retrofitted with the torsional spring friction damper and conventional rotational friction dampers are evaluated using fragility analysis, which shows that the structure retrofitted with the torsional spring friction damper has the smallest probability of reaching the specific limit states.