A variably baffled tuned liquid damper to reduce seismic response of a five-storey building

Abstract

Structural control is considered to be an efficient method to improve the seismic behaviour of buildings. Semi-active control methods have the reliability of passive systems, and at the same time offer the consistency and variability of active systems. In this method, structural responses decrease based on the change in damping properties or stiffness of the system. A tuned liquid damper (TLD) has low manufacturing, installation and maintenance costs. In this paper, a variably baffled TLD is proposed to reduce seismic response of structures and its behaviour is evaluated under near- and far-field earthquakes. Damping of structural models can be changed using an efficient semi-active control algorithm, which acts by changing the angles of baffles. The results show that using these dampers in the semi-active control with an efficient design algorithm for changing the baffle angle improves seismic behaviour of the structural models and reduces the roof displacement. Consideration of the maximum roof displacement and its root mean squared value show that a TLD with variable baffles exhibits excellent performance under both near- and far-field earthquakes, while creating further response reduction under near-field earthquakes. However, the decreases of responses in angles of 0° and 20° are greater than those in angles of 50° and 70°.