A hybrid structural control system using a tuned liquid damper to reduce the wind induced motion of a base isolated structure

This study investigates the use of a tuned liquid damper (TLD) as a cost effective method to reduce the wind induced vibrations of base isolated structures. The TLD is modelled as an equivalent linearized mechanical system in which the damping and natural frequency of the sloshing fluid are amplitude dependent quantities. The base isolated structure is represented using a modified form of the linearized Bouc–Wen model, which enables the behaviour of Stable Unbonded Fibre Reinforced Elastomeric Isolators (SU-FREIs) to be described. The TLD and base isolated structure are combined to form a system of coupled ordinary differential equations, the solution to which produces frequency response curves for the structure and TLD. A preliminary TLD design procedure is presented which allows the proper tank dimensions and damping screen properties to be established. The equivalent linearized mechanical model is validated using time simulations which account for the nonlinear behaviour of the structure and fluid. The models are found to be in excellent agreement. A TLD is found to be an effective means to control the wind induced vibration of a base isolated structure.