Fluid viscous dampers in tackle-damper configuration: An experimental study

This study presents dynamic test results on a recently developed damper placement known as the tackle-damper configuration. This innovative setup integrates a viscous damper alongside two inclined tackles, each comprising multiple turns of wire ropes threaded between upper and lower sheaves. This configuration has the ability to amplify damper deformations and forces based on the mechanical advantage of the tackle. Four specimens of tackle-damper configurations are tested under different dynamic harmonic and seismic loadings. Obtained results indicated that tackle-damper configuration changes pure viscous behaviour of the fluid viscous damper to an amplified viscoelastic behaviour. It is verified that energy dissipation in the tackle-damper configuration arises from two sources, i.e. fluid viscous damper and capstan friction between the wire ropes and the sheaves. Ideally, deformation and force amplification factors in the tackle-damper configuration should depend solely on the number of wire ropes and the inclination angle of the tackle. However, it has been found that true force amplification factor is much larger than the ideal value due to the capstan friction. Moreover, true deformation amplification factor can also be much smaller than the ideal value. This is attributed to the elastic stretching of individual wire ropes within the tackles. Therefore, both friction and wire rope elongation substantially affect the true amplification capabilities of the tackle-damper configuration.