Fluid viscous dampers are installed in buildings and bridges to reduce the impact of earthquakes and strong winds. They consist of an oil cylinder, piston, and rod. The cylinder is divided into two chambers by the piston, and it is filled with viscous fluid. Under earthquakes and strong winds, one of the chambers within the cylinder is compressed by the piston, forcing the viscous fluid to flow through the orifices on the piston into another chamber. As the viscous fluid passes through the orifices, it generates heat energy, dissipating the energy from the earthquake. The damping force generated by the fluid viscous damper is a function of the relative velocity between its two ends. The greater the relative velocity, the larger the damping force. Due to the 90-degree phase difference between the relative displacement and relative velocity of the structure, the damping force is minimum when the relative displacement of the structure reaches its peak. This characteristic allows the damper to dissipate energy without imposing an additional burden on the structure.
Damper force: 0.05 to 300 tonf.
Stroke: +/- 20 ~ +/- 800 mm.
Nonlinear exponent: 0.1 to 1.0.