Seismic Dampers – Friction Dampers

How It Works

Seismic Dampers are used in damping the oscillations of a building during an earthquake. There are many types of dampers for buildings, and damping through friction tends to provide the greatest amount of overall damping. The Friction damper operates on the principles of a coulomb damper, translating kinetic energy into heat by friction.

The Dampers allow the building to move elastically and dissipate the energy of the earthquake. This, in turn, produces substantial savings as structural elements can be optimized for cost savings.

Designed to slip before structural members yield, Friction Dampers act as a reusable fuse and simultaneously dissipate energy. In doing so the building is able to withstand an earthquake without sustaining significant damage to its structure.

Friction dampers are easily modeled and easy to design with. They can be implemented into virtually any project, making it easy to incorporate advanced earthquake engineering concepts into traditional building design.

 

 

Friction damper compare undamped

Why QuakeTek Dampers?

The idea for the first friction damper for seismic control was produced by Dr.Avtar Pall in 1984 and our proprietary manufacturing process and techniques have made the device manufacturable. Our team has perfected these techniques over the last 25 years, ensuring repeatability, reliability and precise tuning for building applications all around the world.

Each friction damper is individually tuned and tested to ensure that it meets the loads and travels modeled by the Structural Engineer.

Our purpose built facility ensures that the dampers are built in the most efficient manner possible and that costs are minimized without Ever sacrificing quality.

Using this technology provides earthquake protection all while creating major savings in structural costs.

While any two steel members in contact will provide coulomb damping, it is often difficult to obtain consistent results.  If set too low the damper could slip under service loads, while if set too high they could fail to slip at all. If poorly manufactured or if the wrong materials are used the friction damper can suffer from stick-slip, experience cold welding or experience excessive bolt relaxation.

Friction dampers must, therefore, be built under controlled conditions, individually and thoroughly tested  in order to ensure that they operate correctly.

Production run of Friction Dampers

Friction Damper Design

Friction Dampers are either modeled with a rectangular hysteretic loop or as a spring. The two main outputs of the design being the required slip load and travel.

With these two parameters, Quaketek can provide Dampers ranging from 20 to 400kips per damper with travels commonly between 1 and 12 inches. Other sizes can be custom designed as required.

Dampers can be designed for indoor or outdoor applications as the finishes can be adapted for different environments.

Sustainable Design

Social Responsibility

As urban sprawl continues and populations in seismic areas grow, our communities and therefore buildings must become more resilient. Earthquakes in or near major cities have taught us time and time again that even if buildings do not collapse, damaged buildings means people are displaced and often left homeless. The poorest members of society are often most affected by seismic events and least likely to have safety nets such as earthquake insurance or the ability to leave the affected area. The current principle of collapse prevention through ductility is simply unsustainable!

The low cost and ease of use of friction dampers, allows governments and societies to simultaneously improve the resilience and environmental responsibility of communities.

Environment

Dissipating seismic energy through the usage of large ductile sections is highly inefficient and wasteful. Producing steel releases 4 tonnes of C02 per tonne of steel produced and concrete is even more polluting, we must therefore be diligent and responsible in our usage of these materials. Every tonne saved by using dampers to dissipate energy instead of more material to stiffen members, directly benefits our environment.