Viscous damper consists of cylinder piston rod, filled the viscous fluid liquid inside the cylinder. When the structure deformed, force the piston moved aligned the cylinder.
Simultaneously, the viscous fluid liquid forced move from one side through the restrained channel to other side, which lead as the damping force occurs.
While the external force induced by Earthquake or wind apply on the structure, due the deformation of the structure will force the Viscous damper action, and the viscous damper transfer the dynamic energy to heat energy (due to the friction and the collision of molecular of the viscous fluid). Which reduce the deformation of the structure keep the structure with more safety and durability.