Experimental study on steel hysteretic column dampers for seismic retrofit of structures

In this research, the seismic performance of a steel column damper is evaluated using cyclic loading tests of two one-story one-bay reinforced concrete (RC) frames before and after retrofit. The theoretical formulation and design procedure of the damper are explained first and then the details of the tests are described. The seismic performances of the test frames are evaluated in terms of hysteretic behavior, energy dissipation, crack pattern, failure mechanism, and damper behavior. The analytical model of the damper is established and verified using the experimental data. In order to further investigate the applicability of the developed damper for seismic retrofit, a case-study structure is chosen and retrofitted using the proposed damper. The seismic performance of the structure is evaluated and compared before and after retrofit in detail using pushover, nonlinear time-history, and fragility analyses. The results show that the presented damper can efficiently reduce inter-story drifts and damage of the structure. The details of modeling techniques and simulations given in this study can provide guidelines and insight into nonlinear analysis and retrofit of RC structures.