Control of Wind-Excited Truss Tower Using Semiactive Friction Damper

This paper explores the possibility of incorporating semiactive friction dampers into wind-excited large truss towers to abate excessive vibration. Piezoelectric materials are used to control the clamping force of a friction damper so as to regulate the slip force of the damper through simple feedback of damper motion status. A rational analytical method is then developed for determining wind-induced dynamic response of large truss towers equipped with semiactive friction dampers and performing extensive parametric studies to evaluate their effectiveness. The proposed bimodel method fulfills the task by alternately using a 3D finite-element static model and a 2D lumped mass dynamic model. Finally, the bimodel method and semiactive friction dampers are applied to a large space steel television tower as a case study. The study demonstrates that the bimodel method can efficiently compute wind-induced dynamic response of the television tower with semiactive friction dampers. The semiactive friction dampers can effectively suppress not only excessive displacement response but also velocity and acceleration responses. Compared with passive friction dampers, the semiactive friction dampers are more robust and versatile for enhancing both serviceability and strength performances of the tower.