A modified friction damper is presented to enhance the performance of conventional friction damper and semi-active variable friction damper. An additional plate is provided be-tween the two sliding plates of a conventional friction damper which results in an additional sliding interface with the same normal (clamping) force. Similar modification is also made to semi-active variable friction damper (SAVFD) to enhance its performance. The enhancement in the performance of the benchmark building is studied under across wind loads by installing the modified dampers. The governing equations of motion are solved by employing state space the-
ory. Optimization of location and number of dampers is also carried out with the help of a con-trollability index which is obtained with the help of root-mean-square (RMS) value of the in-ter-storey drift. Further, a parametric study of passive friction dampers by varying slip force is
carried out. From the numerical study, it is found that both double friction damper and semi-active variable double friction damper (SAVDFD) are quite effective in enhancing the per-formance of the benchmark building. At optimized locations, both the proposed dampers give
significant enhancement in the performance of the benchmark building.