Evaluation of 2D concentrically braced frames with cylindrical dampers subjected to near-field earthquake ground motions

Near field earthquakes have imposed major damage to buildings in the past years. In some cases, the intensity of such damage is too considerable to be disregarded. The most effective way to improve seismic performance of buildings is applying a seismic control technique. The cylindrical friction damper is one of these methods, which has become popular for its desirable performance in the energy dissipation of lateral loads. The main objective of this study is to evaluate the near-field seismic performance of braced frame buildings equipped with cylindrical friction dampers. In this regard, four steel braced frame buildings, including a 4-, 8-, 12-, and 16-story braced frame building are modeled in OpenSees platform. Then, a set of near-field earthquake motions are applied to these structures and the structural response is captured in each story. Results show that there is a direct relation between the optimal slip load and the intensity of the input earthquake. In the next step, the structures are analyzed by selecting the optimum slip load for the damper. It is revealed that cylindrical friction dampers improved structural performance in terms of energy absorption of the structure. However, findings confirm that there is an indirect relationship between the number of floors in a building and the above mentioned feature of these dampers.