A novel tuned liquid mass damper for low-frequency vertical vibration control: Model experiments and field tests

To address the issue of excessive static stretching in tuned mass damper (TMD) used for vertical vibration control of low-frequency structures, a novel tuned liquid mass damper (TLMD) is proposed in the present study, and corresponding theoretical analysis and experimental investigation are carried out. The proposed TLMD consists of a mass-spring oscillator and a tank filled with liquid, with the mass submerged in the liquid. The added mass generated from fluid-solid coupling is utilized to achieve an inerter-like effect. Based on the characteristics and configuration of the device, the analytical model of the TLMD is proposed, and the dynamic parameters of the oscillation system are derived. Three TLMDs with different spring stiffness are designed and manufactured. The frequency reduction effect of the added mass and the feasibility of the proposed analytical model have been validated by free decay tests and forced vibration tests. Finally, the proposed TLMD has been implemented for the first time to the low-frequency vertical vortexinduced vibration control of a large-span cable-stayed bridge, and its effectiveness has been verified through a steady-state excitation test based on a self-developed large-scale bridge exciter. The field test results indicate that after the installation of the TLMDs, the steady-state velocity amplitude of the bridge decreases from 19.9 mm/s to 13.2 mm/s, and the damping ratio increases from 0.198 % to 0.842 %.