Experimental Study and Parameter Design Method on the Performance of a Novel Variable Coefficient Viscous Fluid Damper

In recent years, earthquake performance of buildings has been a hot topic in disaster prevention and mitigation research. Constant coefficient viscous fluid dampers are advantageous in terms of energy dissipation and vibration reduction technology, as they effectively reduce vibrations without adding to structural stiffness, provide good structural adaptability, lower construction costs, and facilitate installation. However, due to their structural deficiencies, they exhibit a mismatch between the increase in damping force and the increase in seismic forces experienced by the structure, that is, they cannot simultaneously satisfy performance requirements under both frequent and rare earthquakes. In this paper, a new two-stage variable coefficient viscous fluid damper, which can self adaptively adjust its mechanical properties to improve the vibration control efficiency of the energy dissipation device. Performance tests have verified that the damper has stable output and good working performance and can meet the actual engineering needs. A design methodology for variable damping parameters is proposed, effectively translating the structural performance objectives to the damper design parameters. Numerical results show that, compared with constant coefficient viscous fluid damper, the variable coefficient viscous fluid damper can increase the story drift angle reduction rate by 10% to 30%. It not only significantly reduces the structural response under seismic action but also meets the specific seismic objectives of various engineering projects through its flexible adjustment methods, achieving energy dissipation at multiple stages.