Tuned Mass Dampers

Tuned Mass Dampers for Bridges, Buildings and other Tall Structures

Wide span structures such as bridges, stairs, and roofs, as well as tall, narrow structures such as chimneys, antennas, masts and buildings, can be easily excited to high vibration amplitudes in their first or higher eigenforms. Excitations can be caused by wind forces, pedestrian traffic, machinery or earthquakes. Natural frequencies and damping are typically low for these structures. With GERB tuned mass dampers (TMD), these vibrations can be easily reduced.

Millennium Bridge – London, GB (Vertical TMD and Horizontal TMD)
Millennium Bridge – London, GB (Vertical TMD and Horizontal TMD)

All GERB TMDs, both vertical or horizontal, have three main components: Spring or pendulum – Oscillating Mass – Viscodamper® (viscous fluid damper).

Every TMD is exactly tuned to the main natural frequency of the structure.

Although TMDs have been well-known for a long time, it is still difficult to provide exact tuning and predefined system damping. Furthermore, the three components must not change their dynamic properties over time, even when exposed to variable weather conditions. GERB has worldwide success in designing and manufacturing TMDs with masses from 20 to 10,000 kg, and vibration frequencies from 40 to as low as 0.3 Hz.

To protect against vertical vibrations, GERB TMDs are equipped with helical compression springs and Viscodampers®. For horizontal and torsional vibrations, GERB supplies TMDs with leaf springs or pendulums, and Viscodampers®.