PERFORMANCE EVALUATION OF FRICTION DAMPERS UNDER SEISMIC LOADS

Several structural control techniques such as passive, active, semi active and hybrid control techniques are gaining importance in earthquake resistant design of structures. Friction damper is a passive type energy dissipating device, which dissipates the seismic energy by virtue of the solid friction developed between the two sliding surfaces. Friction dampers get activated at their slip load and starts dissipating energy. The maximum energy dissipation and least response of the structure occur at optimal slip load of friction dampers. In the present study, the optimal slip load of the friction dampers provided in a nine storey reinforced concrete frame model was evaluated analytically using nonlinear time history analysis. Then the effect of friction dampers on the displacements and forces in the structure was evaluated. Acceleration time histories of El Centro ground motion (N-S component) and Indian seismic zone IV were used for the analysis. The analyses were carried out using SAP2000 computer package. The results confirmed that a good reduction in the displacements and forces is possible with the addition of friction dampers and hence it can be used as an alternative for the conventional ductility based design methods.