Seismic Dampers are used in place of structural elements, like diagonal braces, for controlling seismic damage in structures. It partly absorbs the seismic energy and reduces the motion of buildings.
Types of Seismic Dampers:
- Viscous Dampers (energy is absorbed by silicone-based fluid passing between piston-cylinder arrangement),
- Friction Dampers (energy is absorbed by surfaces with friction between them rubbing against each other), and
- Yielding Dampers (energy is absorbed by metallic components that yield).
Fig: Components of a Viscous Dampers
Tuned Mass Damper (TMD)
It is also known as an active mass damper (AMD) or harmonic absorber . It is a device mounted in structures to reduce the amplitude of mechanical vibrations. Their application can prevent discomfort, damage, or outright structural failure.
They are frequently used in power transmission, automobiles and tall buildings.
Taipei 101 has the largest TMD sphere in the world (shown above) and weighs 660 metric tonnes with a diameter of 5.5 metre and costs US$4 million (total structure costs US$ 1.80 billion).