Research & Development

Since 1907, when GERB was founded, the solution to vibration problems of our customers has been our main target. This has obviously required continuous research and development to keep pace with the fast growing technical level in our business. Research and development is therefore one of our most important activities.

Everything started with two imperial patents in 1910 and 1913.
Then in 1938, William Gerb received a patent no. 659230 - for a Viscodamper® under the title "Device for the Damping of Vibrations". The Viscodamper® is still used today in many modifications and applications.

At GERB we typically do not concentrate on basic research, however, we are determined never to loose contact to actual reality. We, therefore, have taken part - and will do so in the future - in research projects with other institutions, for example technical universities. One such example was a project for the elastic support of a multi-story building directly above a subway line, using helical spring elements and Viscodampers®. In the mid 80s this project, led by Prof. Stühler of the Technical University Berlin, was the beginning of a whole new era, the vibration control of buildings.

Another important task of our R & D division is to define and measure the properties and parameters of new Viscodampers® and spring elements, to develop design procedures and to verify them. A number of test stands are available in our company which can easily be adapted to all typical requirements.

Figure 1 - SCHENCK Test Stand

You will find more pictures of our other test stands in the photo gallery of this chapter.

We maintain regular contacts with Research Institutes and Testing Laboratories in Germany and other countries which can be used whenever necessary.

Another major task of the R & D division deals with "Tuned Mass Dampers" Dampers (TMD). Quite a number of pedestrian and other bridges have been equipped worldwide with GERB TMDs, as have been football-arenas, towers, stacks or simply elevated factory floors. Each of these TMDs is tailor-made and has to be tested to guarantee its required properties.

One of the most spectacular and recent examples is the Millennium Bridge in London designed by Sir Norman Foster as a pedestrian Thames bridge which had to be closed right after the opening day because of high vibration levels. To solve this vibration problem a complex system was developed.

Figure 2 - Excitation of a Multi-dimensional TMD

The original idea was to use multidimensional TMDs for which GERB developed a prototype (see figure 2). Although the test results on site were quite promising, an alternative solution was more favoured. In the final solution 58 GERB-TMDs in 12 different sizes and shapes where developed, designed, manufactured and installed, together with a couple of other shock absorbers. An example is shown in figure 3. Many special requirements had to be taken into account, not only certain geometrical and optical limitations but also some related to the technical properties of the integrated Viscodampers®, which forced our R & D division to develop a completely new damper concept.

Figure 3 - Vertical TMD.

In addition, the customer asked for major test series to prove compliance with the requested tolerances of frequency, mass and damping of the TMDs.

Tests after installation of the TMD finally have proven proper functioning in reality, hence shortly after the installation of these TMDs the Millennium Bridge could be reopened.