Viscous Dampers – Vibration Control Devices for Buildings, Bridges & Mechanical Equipment

Viscous dampers, also referred to as earthquake dampers, seismic dampers, or fluid viscous dampers, are energy dissipation devices commonly used for structural vibration control. Through the reciprocating motion of an internal piston, they generate shear action within the damping medium, thereby absorbing and dissipating vibration energy caused by earthquakes, wind loads, or mechanical operations. They are widely applied in buildings, bridges, and industrial equipment. The fluid viscous damper, as a type of viscous damper, is distinguished by its use of high-performance liquid as the damping medium. It achieves more efficient energy dissipation through precisely engineered fluid channels and orifice structures.

Structural Composition

A viscous damper consists of a spherical bearing rod, hydraulic oil chamber, damping orifice, guide rod, piston, cylinder, sealing ring, and other components.

Working Principle

The viscous damper is filled with a viscous fluid (e.g. silicone oil) and is equipped with a piston structure. When a structure experiences relative displacement due to external forces (such as earthquake or wind load), the connecting components at both ends of the damper move relative to each other, causing the piston to move within the cylinder. As the viscous fluid passes through small orifices or gaps in the piston, a damping force is generated, converting the structure's kinetic energy into heat and dissipating it.

Features

• High energy dissipation. It dissipates large amounts of vibration energy, providing significant vibration reduction.
• Velocity-dependent. The damping force is related to the piston velocity and is insensitive to minor vibrations.
• Durable and reliable. Excellent sealing performance and a long service life (typically over 30 years).
• Simple maintenance. No external power required and virtually maintenance-free.
• Temperature stability. Specially formulated fluid ensures stable performance across a wide temperature range.

Installation

Applications

• Bridge structures: Used at bridge pier tops, beam ends, and similar locations, viscous dampers mitigate vibrations caused by earthquakes or wind loads.
• High-rise buildings: Used in combination with shear walls and frame structures, viscous dampers significantly reduce inter-story displacement and structural acceleration induced by earthquakes.
• Industrial plants and equipment foundations: Installed on the foundations of large-scale machinery, viscous dampers mitigate the impact of operational vibrations on building structures.