Wall-type Damper

• It is effective for absorbing a wide range of vibrations, from wind vibration to violent shaking caused by strong earthquakes.
• No maintenance is required as the viscous fluid remains stable over many years, and there is absolutely no leakage of fluid.
• VWD can be designed to suit the scale of the building and vibration damping required.

The Oiles Viscous Wall Damper is a vibration attenuator using the shear resistance force of a highly viscous fluid. It consists of outer steel container filled with a viscous fluid and an internal shearing plate.

The relative storey displacement induced by an earthquake or a strong wind produces movement of a shearing plate fixed to the upper beam relative to the viscous fluid container fixed to the lower beam. The resistance created by the movement of the shear plate in the viscous fluid effectively absorbs the vibration energy.

This chart shows the relationship between force and displacement when VWD is subjected to the motion expected during a major earthquake. Design values correlate well with actual measurements indicating stable performance and accurate design methods. The hysteresis loop of VWD produces a smooth curve, test results indicate stable damping is achieved during motion from small amplitude low speed vibration to large high speed shaking.

• Horizontal vibration force/±300tons
• Maximum horizontal/±200mm

Basic performance tests of a VWD from low to high speed demonstrated that a stable damping function could be obtained during motion from small amplitude low speed vibration to large high speed shaking.

Response to a seismic wave was tested to verify the characteristics of VWD for actual buildings during a major earthquake. Results show actual measurement coincide with calculated values, verifying safety in a major earthquake.