Finite element modelling of a TLD with inclined damping screens

Current trends in high-rise structures include increased heights and the use of lightweight and high-strength materials, which has led to very flexible and lightly damped structures. As a result, structures of this type can display increased sensitivity to external dynamic excitation. Among the different solutions considered to control their response, dynamic vibration absorbers (DVA) have been introduced and found to be very effective. A tuned liquid damper (TLD) is one of the more commonly employed dynamic vibration absorbers. The performance of a TLD for a given mass ratio is a function of the tuning ratio and the inherent TLD damping ratio. The damping ratio of a TLD equipped with fixed vertical damping screens is related to the screen pressure loss coefficient (Cι) and the square of the fluid velocity at the screen location. Therefore, the inherent damping ratio that develops due to the screen is amplitude dependent. In this paper, a nonlinear TLD fluid model is updated and validated with experimental results to simulate the effect of inclined damping screens. A pressure loss coefficient (Cθ), which is a function of the screen inclination angle (θ), is utilized for the damping effect of the angled screens.