The implementation of semi-active friction damper for vibration mitigation of seismic structure generally requires an
efficient control strategy. In this paper, the fuzzy logic based on Takagi-Sugeno model is proposed for controlling a
semi-active friction damper that is installed on a nonlinear building subjected to strong earthquakes. The continuous
Bouc-Wen hysteretic model for the stiffness is used to describe nonlinear characteristic of the building. The optimal
sliding force with friction damper is determined by nonlinear time history analysis under normal earthquakes. The
Takagi-Sugeno fuzzy logic model is employed to adjust the clamping force acted on the friction damper according to the
semi-active control strategy. Numerical simulation results demonstrate that the proposed method is very efficient in
reducing the peak inter-story drift and acceleration of the nonlinear building structure under earthquake excitations.